Revenge of the Smelly Ducting
March 27th, 2005
For about a month now, we’ve had this odd odor in our house. It started out in our laundry room, on the east end of our main floor. Then we noticed it in our bedroom, on the west end of our 2nd floor. Since then, we’ve noticed it in almost every room in the house on different days, but never all over at once. It’s always one or two rooms, but they could be on opposite ends of the house.
I few weeks ago, I realized that the smell was coming from the furnace vents. After some experimentation, I noticed that running the furnace made the smell go away. It got worse when the temperatures were warmer, and the furnace wasn’t running.
So we called out our local heating/plumber guy. After they were out here three times, they did find a couple of problems with our furnace, but no gas leaks or anything that could explain the smell — which, by the way, three different employees couldn’t identify. They even left an air charting unit with us, which ruled out things like carbon dioxide, carbon monoxide, and particulates. It did helpfully notice that there were odors, but didn’t tell us what they were.
So here we are, still smelling this…. smell. It defies categorization. It mystefies experts. Something like a cross between dirty laundry, mold, and a skunk. And yet…. none of those, either. It’s weird.
I’ve taken to closing the vents in our bedroom before turning in for the night if the smell is bad in the evening.
So, I’m appealing to all the bloggers out there for suggestions, short of selling the place and moving to town :-)
Oh, and this is not the first time we’ve had odor problems here. However, the cause the first time was immediately apparent and thus could be eventually dealt with :-)
Categories: General
John, can it be a ’sewer, or sceptic tank’ smell being moved by the wind that day. My daugther had a smell and a wet basement wall that tricked us for a year. Finally figured out the sewer line was cracked inside the basement wall. No leak inside or outside, but in the wall. Just a thought. It would seem however that a H/C guy probably already eliminated that prospect. Ours wasn’t a true sewer smell because the water we were dealing with could probably only be classified as grey water.(leak was small enough not to allow any solids to escape into the wall.) c
Reply
Some things to check
1. Air intake for furnace (should be one leading to outside) is clear and no smell near it outside
2. Furnace filter is cleaned/replaced and put in correct orientation
3. could have ductwork cleaned out (can DIY a bit by using a shopvac to clean out first three/four feet at each vent in each room)
4. no cat litter pan or anything like that in basement or near cold air return vents
5. cold air return ductwork is clean
6. cold air return vents cleaned out and working properly
If you have a forced-air furnace, consider that when the furnace comes on, it sucks down a lot of air and moves it around so…
You may need to check for mold/mildew. Does your laundry dryer vent properly outside? (if you vent inside, the moisture can cause mold buildup) While you’re checking your dryer, if your hose is more than a few years old, replace with a clean metal one.
Have you looked in your attic? Check for dead animals, mold, etc. And while you’re up there, see if you have enough insulation! (you can then run your furnace less)
Reply
Our furnace is in the basement, and the cold air return goes from a room where we’ve never noticed the smell — and we haven’t noticed the smell in the basement, either (until yesterday, but even then, not in the utility room). I’ve also stuck my nose into the attic and our crawlspace and haven’t detected anything.
I too have wondered about the ducts, or maybe the heat exchanger. We first noticed the problem on a warm (for late winter) and humid day, which was nicely situated between cold spells… wouldn’t surprise me if we got some condensation somewhere.
I suppose it could be a sewer or septic smell, originating from somewhere other than the utility room or crawlspace. Hmm. I’ll have to mention that.
Thanks!
Reply
I too, have that smell in a 3 yr old house we have just purchased, no heat running, and the oder comes and goes, thinking maybe dead animal in the duct work,
Reply
jgoerzen Reply:
July 10th, 2005 at 8:23 pm
Ours eventually disappeared over time… the people we talked to thought it probably wasn’t a dead animal because the smell lingered so long. We never did figure out what it was.
Reply
sue Reply:
January 23rd, 2008 at 4:51 pm
How long did the smell linger for. I think we have a dead something in our heating duct.
Reply
brenda Reply:
March 24th, 2009 at 7:47 am
We just had a dead cat removed from our duct work yesterday. She had pulled down the collapsible part and crawled into the main duct and died. The smell was horrendous. After removing and deodorizing the smell left.
shaydee318 Reply:
October 16th, 2008 at 8:09 pm
We have a similar problem too. Outside of our house you can smell this odor up the street people past by and look at us crazy like we are nasty people and we are not. Our neighhbors talk about us and when we come outside they get so quiet. We moved in right before my husbands grandmother died, and the house was already messed up but clean as it can be , just smelly. I wonder where the smell is coming from. We don’t know what to do about the smell because the house is old and we don’t have money to remodel it right now. This is a pain in my ass.I read that we could check the air ducts but thats money we dont have. Someone please give me some advice.
Reply
DMW Reply:
November 15th, 2005 at 7:17 pm
Just in the last two months I have found an odd smell in my cold air return. My furnace is not even a year old and I did not notice a smell during last winter or spring/summer. It is driving me crazy and I am making my husband crazy by having him remove vents and look for something dead. No plumbing near the vents so I, too, am at a lost!
Reply
Anonymous Reply:
December 5th, 2005 at 8:51 pm
turn off your electronic air cleaner on the furnace- worked immediately for us
Reply
Dana Reply:
August 3rd, 2007 at 10:57 am
There is a horrible sweet skunk smell in my daughter’s bedroom. Today is the fifth day since we’ve recognized the smell. My daughter cannot even sleep or go in there, the smell is so bad. We had to look in the attic, nothing there. At first we detected it coming from the vent high above my daughter’s dresser. Now it’s right when you walk in. Once you smell it, you want to run away!
Reply
Nicki Reply:
October 8th, 2007 at 10:14 pm
Did you ever locate the source of this smell? We have the exact same smell (sweet skunk is how I described it), started under our bathroom sink. Now it’s in my daughter’s closet on the OTHER side of the house, but gone from our room. Plumber can find nothing. Pest control can find nothing.
Reply
Did you ever figure out what it was? We just started noticing a very similar thing this last week and we are pulling our hair out. Has anybody reading this ever solved the problem or figured out what”it” was???? Thanks!
Reply
jgoerzen Reply:
September 28th, 2005 at 8:57 am
Nope, we never figured it out. It slowly disappeared over time. Very, very strange!
Reply
Anonymous Reply:
October 26th, 2005 at 6:27 pm
Sniff around - particularly near the drains in the basement to see where the smell is coming from. If you have a basement that has a drain, the smell could be coming from the drain and spreading to the rest of the house when the furnace fan turns on. The smell could be coming out of the drain since the trap may be dry. Pour a gallon of water into the drain and see if that prevents the smell from getting into the basement.
Reply
I don’t know if you ever figured the odor out but we bought a new house and had the same problem. Finally we found out it is coming from the electronic air filter on our furnace. We turned it off and the smell went away. Thank God– it was driving me crazy
Reply
Bill Reply:
December 15th, 2005 at 6:56 am
Sound similar to a problem I’ trying to figure. Everytime someone takes a long shower a sudden burst of foul air comes through the cold air vent inside the living room. Anyone have an idea?
Reply
Anonymous Reply:
December 15th, 2005 at 1:05 pm
We are having a similar problem. Every time we shower and use hotwater and kick our furnace on it creates a very foul sewer smell. Noticed it coming from the ducts, so I tracked it to the basement. I noticed that it was coming from a non-caulked hole where my air intake and exhaust exits the house. Above that area is a screened porch with a tile floor. The exhaust and intake travels the length of the screened porch and comes out in the open air. The other area that wasn’t caulked was drawing air becasue out hot tankless water heater was drawing air from the outside (tight house) to feed it. Well, our setic tank sits about 8 feet from the edge of the porch and we are thinking that the gas from the tank is escaping, getting trapped under the porch and when the heat kicks on it draws it into the house. Can’t smell it outside, but you can tell it is coming from the outside. We caulked this area and the smell stopped. Found another area I need to caulk tonight to stop it there too. Hope this helps. It’s a really strange occurence. House is only six months old. I’m going to have the HVAC guys run another air intake into the furnace room where the tankless water heater is. This should the allow the water heater to suck air from that pipe run to a more open area outside (fresh air), rather than sucking the trapped gas under the porch through small cracks in the walls under it.
Reply
I am having the same problem. Please let me know what you come up with because it is so weird.
Reply
jgoerzen Reply:
January 23rd, 2006 at 8:24 am
We never found the problem — it just disappeared after awhile.
Reply
Anonymous Reply:
February 1st, 2006 at 9:03 am
How long is ” a while”? We are wondering how long we will have to live with the smell!
Reply
We just went through this over the weekend. Not sure if yours is the same problem, but we noticed this horrible smell for a few days, but it just suddenly got worse one day. It seemed to emanate from the basement in the laundry room. We checked ducts, drains, the works, and finally we found it! It was a dead animal of some kind in our dryer hose that vents to the outside! The flap cover had broken long ago and I guess this little animal wanted to get warm. It was a nasty gross mess, including some maggots and potato bugs ACK! We cleaned out the dryer and replaced the vent cover and dryer hose. It’s been 2 days now and the smell is finally going away. Check your dryer hose, and the flap cover to the outside….maybe you’ll get lucky with that. Hope you find your problem
Reply
I have been having a problem with smell off and on for over a year. It doesn’t matter if it is hot or cold, heater running or not. Seems to be comming from heater vent. Nothing in crawl space that I can see. ANY suggestions???
Reply
Kelly Reply:
August 15th, 2006 at 9:21 pm
We have a smell that sounds like yours. It is such a foul smell that it really defies explanation. It is like a dead rat (which we have a big problem with), with a little musty odor and skunk type smells all rolled together. It is just awful. We just purchased our house and haven’t been in it more than 3 weeks and I am going crazy with this smell. I haven’t called any experts in yet - but I am going to. The smell is coming from 2 floor vents in our house. The heating system is really old - I am wanting to just rip out the whole thing. Any suggestions would be helpful!
Reply
Connie Stock Reply:
September 25th, 2007 at 12:49 pm
I am so glad that we aren’t the only people with this awlful smell coming from our vents. We have had the air conditioning man to the house and he can’t seem to figure it out. It smells like rotten eggs. We’ve had it a couple of years. It seems to be worse in the summer when the air is running. If we are not running the air or the heater the smell is gone but if its on then we have the smell. It’s terrible and embarrassing. If you find the problem PLEASE let me know.
Reply
ELECTRONIC AIR FILTER: someone mentioned this as the problem and solution. We have had this problem too. We have two systems in our old house and the electronic air filters are the cause. I dont know why. But turn them off and the smell is gone the next day. I think it has to do with the level of humidity in the air. When it is more humid the filter generates this smell. In our case it wasn’t a maybe - it was the problem. Every once and a while I clean them and put them back on and eventually the smell comes back. They sit off and were a waste of money.
Good luck.
Reply
Melissa Reply:
September 16th, 2008 at 6:24 pm
How do you know what the electronic air filter is and how do you turn it off?
Reply
If anyone could help me I would sure appreciate it. Feel free to e-mail me. I have a dead animal odor coming from my heating vents and the furnace isn’t even on. It’s putrid. I just spent 330 dollars having all my ductwork cleaned and sanitized and two days later the smell is back. When it came back very suddenly today, I noticed the side of my furnace where there is an air vent really stunk. I took off the vent and the smell just emanated from somewhere in the furnace. (or so it seems) I have also worried that it is some sewage problem although I don’t have septic and it does seem to come from the furnace area. I have had to block all my heating vents with cardboard. The smell goes away once the heat has been on a while, but returns as soon as heat is off.
I’d appreciate any thoughts.
Reply
Olga Reply:
September 12th, 2006 at 8:47 pm
Linda - I read your comment and we are in the exact same scenario. I spent 400 bucks today having the ducts cleaned and now I’m still smelling that terrible smell. Did anyone reply to your question? have you gotten rid of the smell? One other thing that I’ve noticed is that the smell only comes when the temps outside are cold (below 50 degrees). Perhaps the cold air is somehow pushing the smell around? My husband and I are very upset, since we love everything about this house (just purchased 2 months ago) but we can’t stand the smell! HELP!
Reply
Sam Reply:
December 5th, 2006 at 9:29 am
Did you figure this out? We have a similar problem, cold mornings, a sweet smell comes out of the main intake vent in our bedroom..
Reply
Arvid Reply:
October 15th, 2007 at 12:13 pm
Turn off your electronic air filter. We did & the house was oder free in one hour.
Reply
patricia Reply:
April 26th, 2007 at 12:06 pm
please let me know if u found out what the problem was with your smell in your vents, we have the same thing, it is horrible, email me at stretch1946@hotmail.com thanks
Reply
christine Reply:
May 17th, 2007 at 9:23 pm
Gross thought it may be, rodents urinate and poop in the vents. This is one smell that lingers even afte they have left and when the heat comes on so does the smell. This will not go away until you flush out the vetns. One thing rodents do not like is the smell of bleach. Whislt this may be difficult for you to stand you should flush out the vents and every few weeks put some bleach in and you will see the lottle critters leaving. I had a huge issue in a pantry on our farm then after scrubbing it out every few days I spray some bleach around. I haven’t seen the little beggars for a year. Also my husband spread lime in our crawl space. This gets rid of any msell and discourages them from returning.
Reply
We have been having the same problem. We just moved into our 150+ year old house(it was rehabbed) 2 1/2 months ago. The first month we didn’t have any problems. Now anytime we run the shower, this sewage/marshy smell comes through the vents. We had a septic guy look at the septic system and not finding any obvious cause, he thought a second vent would help…well it didn’t. We are thinking about getting a plumber in here next. We also had a dead animal smell coming out of the hole in the wall for the hot and cold water pipes leading from the basement into the kitchen when we ran the washing machine. We filled the hole up with expanding foam and that seemed to have helped. Running the sinks and the toilet haven’t caused the smell yet all the water goes down the same pipe out to the septic tank. It is strange
annoying and embarassing. We are desperate to get it to stop. This is our first home and we really want to love it, but right now it’s hard to not be frustrated.
Reply
Help! I have a related problem. Last week, I found out that my apartment furnace was emitting 600ppm of CO. So I had the furnace replaced with a brand new furnace, with new ducts, fixtures and all. A few hours later, there is this smell which is hard to define. A mixture of skunk or dead animal type smell which is lightly suffocating and highly discomforting. There is no blurring of the eyes with this smell. I am sure that there is no gas or CO leak since furnace was totally replaced. Also smell emanates from the vents. Area around the furnace itself has no smell.
Thanks in advance for any advice on resolving this issue.
Reply
Donna Williams Reply:
November 20th, 2006 at 9:43 am
I would like to share with you our battle with our illusive smell from our basement. Our home is 17 yrs. old and is not using a septic sys. Our smell is a cross between sewage & sewer gas smell, musty water and ???). A good plumber recently replaced two toilets on main level, both had faulty seals. But the smell came back-! Replacing toilet seals is relatively cheap and easy and is a good idea as sewer gas can escape from beneath a bad toilet seal and sink into the basement (so I have been told). We have replaced our hot water heater, thinking the anode rod was corroded. The smell came back. We have repaired our water main into the house (cracked off INSIDE the basement foundation approx. 2 years ago). Smell came back-!! NEXT WEEK, we are having our dryer vent checked. Thanks to your comments, I have learned there is a real possibility that something met it’s death inside my dryer vent, which is many many feet too long, installed incorrectly with bends and twists that very possibly are holding massive amounts of soggy dryer gunk and Lord knows what else. I will now turn OFF my electric air cleaner. It’s a process of elinination I am learning. Our plumber is coming back after the dryer vent is cleaned and checked and will (hopefully) do a smoke test, where the smoke bomb is dropped thru the stack on the roof to identify leaks. Smoke bombs like this are apparantly hard to find here in Chicago (short shelf life) and I am hoping he does manage to get his hands on one. Thanks for the sharing of ideas, I too will pass along our finding on the road to eliminate the STINK!
Reply
vonn Reply:
November 2nd, 2007 at 12:12 pm
We have a horrible smell also and can not find out what it is!! I can not stand the smell anymore. Does it smell like a gas? We have had different people out here and they can’t find anything.We have a boiler system so no register vents. Help if you find a solution.
Reply
I have spent the whole day smelling this f’ing smell in the basement and its exactly what u guys are describing…Having no smell from the vent or toliets or anything…but I noticed its comeing from the corner of the cealing…We took off the plug in and it smelt like skunk..any sudgestions? I do believe its a dead rat or something….we are probably going to rip off some dry wall and find the problem….
Reply
hello, we too have an odor that has just recently begun 3 or 4 days ago. woke us out of a sound sleep. but in our case it seems stronger when the furnace is running. is this a different problem?
Reply
Teri Reply:
December 4th, 2006 at 9:19 pm
I am having the same problem. I am seriously considering turning my furnace off and buy electric heaters for every room! The smell was bad about 2 months ago. Then it went away completely. Now it’s back with a vengance! You can smell it all the time but when the heat is on it gets 10 times worse. I have seen posts saying to turn off the electronic air filter . . . would this be a switch that is on the wall? I have a switch that is in the “on” position but I don’t know what it is for. Any help, I will be forever grateful!
Reply
HELP!!! My husband removed the vents to install these scented vent paks, but upon doing so he cursed us with this FOUL ODOR!! We had the ducts cleaned and deodorized. It worked for a while but now he removed the ceiling fan to replace it and now IT’S BACK. It smells like an animal rolled in standing water. Please help me.
Reply
No, we never found the cause of the problem. It simply went away with time.
Reply
I get this same problem every year when it gets cold. I suspect that it is a downdraft from my furnace. I do not have a combustion air intake because it can draw enough air from the basement. I think as it is running it creates a negative pressure in my basement. After it stops, the negative pressure draws air from the roof vent back into the house. My plumbing stack vent is a little lower than my furnace vent on the roof. I think the cold outside air is trapping the warm plumbing vent air and keeping it close to the roof. If anyone has had this similar problem, have you had to install a separate combustion air intake? I have seen a product that is a charcoal plumbing vent filter that is supposed to eliminate vent odors. Has anyone had any luck with this?
Reply
Check to see if your condensate drain from your A coil in your Air handler is installed properly. if it is not the sewer gas can come back up that drain pipe right into your ductwork.
Reply
Even if the drain is installed properly in the winter time there is less humidity and the p-trap could dry out and let sewer gas by. Try draining it outside independant of the drain system.
Reply
Someone from this site e-mailed us directly re: a post we left in 2005. We sure did find out what is was! Not one, not two, not three, but 4 DEAD SQUIRRELS! 3 had buried themselves deeply in the attic insulation and even under some duct work (it was tricky and very gross to retrieve and dispose of them, and my husband deserves high praise for doing so). The other was under our crawl space. It was right after a hurricane and we figure the squirrels came in looking for shelter. We had 3 again this year so as soon as we noted the smell, we searched and found. I urge all of you with this issue to look for dead animals in your insulation and crawl space. jt
Reply
ethel wright Reply:
December 18th, 2006 at 9:56 pm
i have this putrid odor coming into one bathroom, you cant tell if its from the heating vent or the drains , plumber has been in three days in a row ,i have spent almost $4,000. no animal yet found.,or just were this stench is coming from,i will have the men search in the attic, most of the septic tank pipes have been replaced in the crawl space out thru the wall thanks for sharing your info with us
Reply
I need help with a smell that is plagueing us 24 hours a day, 7 days a week, warm or cold weather.
It’s definately sewer but it’s comming form our heater vents. We both this house just recently and have been in it for about 4 and a half months, and the smell is enough to make not only us, but anyone that comes over gag.
The heater ducts weren’t even sealed, only nailed to the sides with large gapeing holes, which I have sealed off. However, the Electric Furnice stinks, the smell comes from up under the house, in every room…the kitchen, living room, all four bedrooms and both bathrooms. There is no “apparent” sewer leak that can be seen…
Please help. We have been trying to get someone to go under the house, but no one will, as there is some sort of standing “liquid”, and we were advised not to go under the house untill summer…but we can’t live like this.
I’ve contacted my agent, the previous owners agent, the city, the county, plumbers, heating companies, etc…
I’m at a dead end. :(
Thank you to all that respond.
Reply
We had this problem a few years ago, in my boys bathroom. We had people come and check out our vents and said they were clean and no holes. My boys were little and had potty trained the two years before, so I figured well maybe it was the wall behind the toilet. They don’t always hit their target. :) So, I decided to tear out the wall and put in tile. That way it would be easier to clean. When I began to tear out the wall, I realized I was going to have to take out the tub also. Anyway, mice had gotton into the walls and were under the tub. They brought with them dog poo, dried mushrooms and other things. The mice were rotting in the walls. It was so gross! Under the tub and in the walls was where the smell was coming from. We had to tear out all of the walls in the bathroom, and redo the whole thing. The smell went away. Our house was only a few years old then, that was several years ago. There was no obvious spot that we could see that they were getting in, we checked all over for holes. We now have the problem again, and now I not only have sheet rock to take out , but tile! Here we go again. Good luck!
Reply
Hello! Previously when our furnace has clicked to turn on but no air is blowing out, a foul urine smell develops in our house. I don’t know what may cause this, however we do have a mold issue downstairs. So if you have any suggestions of what I should do that would be great! I am scared that this will cost a lot of money, in which I dont have!
Reply
Help! My house stinks at first it was in the back hall this funky smell now it’s everywhere. It seems to be comming up threw the heater vents all over the house. My husband checked for dead critters and found none. NEw house we built only a 1year old….Need advice before I go crazy…
Reply
jeaniek Reply:
February 6th, 2007 at 8:09 pm
we had the same new home problem. after ripping apart all the basement ductwork, we accidently found our drain pipe from the common bathroom wasn’t sealed when the builder installed it. th pvc pipe was next to a cold air duct which sucked sewer gas into our hallway and master bedroom. once my husband sealed it the smell was gone!
Reply
Dave Reply:
February 17th, 2007 at 4:36 pm
We noticed a horrible smell in the house and it was only getting worse. I went around the house smelling each vent and found one that smelled more potent than the others. I called a few duct cleaning people and they recommended getting a pest control specialist to come out and look around first. I called a few and never got a call back so I decided today to go in myself. They weren’t kidding about the “crawl” space, this not a place to go if you are claustrophobic. I made my way back to the corner where the nasty vent was. Right away I noticed that the insulation was hanging down in that area. I pulled down the piece closest to the vent and a dead rat fell out along with a few weeks worth of poo. The smell could have knocked a maggot off a S**T pile from 100 yards. It was down right nasty, but the smell is gone and feeling that I had just saved a butt load of money made it even better. I was really surprised how something outside the duct work could make its way in. We smelled it all through the house, but in the end it all came from that small area. Hope this helps somebody.
Reply
B Reply:
February 26th, 2008 at 1:53 am
We are taking your suggestion and looking in the crawl space tomorrow. We had gone down before and smelled nothing around there, but today we went and checked again and its like hitting a wall when you go into the basement(previously only the upstairs had an odor). I really hope this is the cause, because nothing else we have tried on this page has helped.
One man said he thought that a skunk had sprayed, but that cant be it because the outside of the house barely has a scent compared to inside.
Also everyone that has smelled it says it smells like skunk to them, to me and only to me, it does not smell anything like skunk but more like something burning mixed with sewage. Very frustrating!
ps. if we do figure it out I will repost because many people havent and it is frustrating not to know what caused the smell in the cases that might pertain to me.
Reply
I’ve just had this problem today, a strange smell from the closet that goes down to my basement. First I thought it was from the shoe boxes we had, but as I got closer to the basement underground door the smell got worse. I’m pretty sure the smell is from the basement which I’m afraid to go in now. I also smell it slightly from the bathroom next to the closet, also in my garage near the heaters, but these locations the smell is not as strong.
A few months ago I’ve seen a small rat running through my garage and outside of my house, and I do believe they’ve made my basement their nest. If my prediction is right, the rat probably found a hole near the heater and went down into my basement, since and stayed there for the heat.
My second thought on this problem is a sewage pipe leak? and a backup of stinky gas. From just the smell of the odor I cannot tell if its a backup gas or is it a rotten meat/dead rat smell… cause honestly I’ve never smelled either. So I have no clue which one it could be. Right now the house smells fine as long as i dont open that closet… But I’m calling the pest control to find out the problem. Anyone know how much it might be? If it’s over 200 dollars I might just do it myself. But hopefully it’s not.
Reply
We have had a stinky problem for months now. It’s really strong when running the washer and the furnace is on. We’ve checked everything with the washer, that’s not it. Today I was cleaning out the floor heating registers and found water standing in one of them! The smell just about made me pass out! This register is on the other side of a bathroom that we do not use. (Toilet backs up into shower, but that’s another problem). So, my guess is when the washer drains it is getting in this duct, and the air from the furnace is making the smell worse. How do I go about finding out where the leak is?
Reply
BrdgeFairy Reply:
April 26th, 2007 at 3:03 pm
Or has the toilet overflowed recently and run across the floor to the furnace duct? Clean the water up and see if it comes back after a couple of days without overflows.
If it comes back when there has not been any overflows, I’d guess there is a water leak or a sewage leak.
The seal on that toilet may be bad. The sewage may just be seeping through the floor and puddling in the furnace vent.
It could also be a water leak in the wall — or a cracked shower floor — or some boys that like to play water pistols with the hand-held shower head.
If you can rule out rambuncious boys, get under the floor in that area, take down the insulation and follow the water stains.
If you can’t get under the floor easily, the other option is to just replace the toilet seal and see what happens. If your toilet seal is more than 5-10 years old it very easily could be leaking.
Good luck! b.
Reply
My wife and I have been enduring a smell for 2 years since we bought a Sears Historic Home, aka money pit. I just read a bunch of the emails on this page and I now realize I am not crazy. Trying to describe the smell and find out where its coming from is the most frustrating thing I have ever endured. Im so ready to be done with this that I would eat a dead rat in slow-motion if that would make my smell go away. I dont have the energy to type my saga because Im out of energy. For god sakes, cant plumbers figure this s**t out. Ive had 4 plumbers and all of them are baffled. My condolences to you all!
Reply
vonn Reply:
November 2nd, 2007 at 12:21 pm
Golly, Am I glad we are not the only ones! No one can find out what this smell is. We have a boiler. Email me if you find the answer.
Reply
We live in a condo building that was reahabed 2 years ago. Everyone in the building has the same washer and dryer but we seem to be the only ones with the smell. And it seems to be coming from our inside our washing machine. It is exactly the smell everyone is describing which is wet animal/musty/moldy. Miraculously our clothes don’t smell. I notice that it is worse when it is really cold outside and we just over a really cold snap here in Chicago. Occasionally it travels through the condo but for the most part it stays by the washing machine, which is located in our hallway. Any suggestions?
Reply
We’re going on our 3rd year of intermittant sewer smell in one corner of our finished basement. We’ve checked the drains, but the smells strongest right when you get down the steps. There’s just a wall there–it’s the edge of our basement. Every year, in the fall, we think the smell goes away… and maybe it won’t come back. But then every spring it’s back again.
This is roughly when we stop using the heater during the day (though the nights have still been cold lately).
The basement was finished when we moved in, so we’re hesitant to start ripping up carpet or tearing down walls.
We thought it might be something dead, but it only happens in the spring/summer.
Anyone have any ideas?
Reply
vonn Reply:
November 2nd, 2007 at 12:24 pm
Oh yes, we have the same problem but it is summeer and winter!! Email me if you can.
Reply
UPDATE: So we tore up some carpet last night and found…
a bunch of cracks all leading to a concrete-filled drain!
The cracks smell so we think it’s the dried up drain, leaking sewer gas through the cracks.
Not sure how we’re going to fix it yet, but at least we think we’ve found the problem!
Reply
???? Where is this electric air filter switch? I am trying to see if that will help. TIA
Reply
Makes no sense… We have a similar problem, skunky smell that comes and goes, but only on the second floor. No easy way for skunks to get into attic, it’s 2 stories up.
The smell comes and goes… you’ll walk and catch a whiff of it but can’t really tell where it’s coming from.
Not the heating vents - we have hot water radiators… and the smell has been in the summer and winter.
it’s very odd…
Reply
vonn Reply:
November 2nd, 2007 at 12:27 pm
Sounds just like our problem anyone out there help please.
Reply
Jan Reply:
February 14th, 2008 at 3:53 pm
did you ever find out what the smell was? we have the same problem.
thanks
Reply
Hi there,
I stumbled across this web site and I feel very relieved, I live on the 32 floor in a condo and I have Noticed a very strange smell coming directly from the heating vents about 2-3 times a day. Of course, I have had the condo heating people in BUT the smell is Never present when they are here. I have NO idea what the smell is or where it is coming from. It is a strange, small potent type smell and it is driving me crazy! It seems to come and go, sometimes I stick my nose near the heat vent (which is off) and I can almost taste the smell, then 20 minutes later I stick my nose near the same vent and the smell is Gone! I don’t think it is coming from my neighbors b/c I know what bad cooking smells like and this is not it….I think I am going crazy … any sugesstions as to what the heck this smell is???
Thanks,
Carol
Reply
Teresa Batchelor Reply:
May 18th, 2007 at 4:56 pm
Im having the same problem in my bathroom, It smells as if a rodent is dead in my duct work. In time the smell will probably rot away, but a neighbor told me to put charcoal in and around my vent work. She said that charcoal will absorb any foul odors, until the rodent rots away. Im headed to the store now. I hope this works!
Reply
Hello all. I don’t know if I should be happy that I found this website because it describes my problem exactly or sad because it seems there is no real solution to this problem:-)
One question I have is about this ‘drain’ or ‘drain pipe’ everyone seems to be referring to. Where exactly is it? so I can find out if it is improperly sealed or needs some trap water?
Reply
I just moved from a condo that had a gross smell coming from a bathroom. We could not figure out what was causing it. While trying to sell the condo we had a ritual of things to do to mask the odor while prospective buyers came thru . We sold the condo and gave the new owners the problem. Well guess what ? Yep my new house has it now ! It is also coming into a bathroom. This time the smell is very strong from the vent on the floor. I have read about HUNDREDS of possibilites for the cause, but not many answers. I am having a man come tomorrow to clean my vents. I guess I’ll start there. If all else fails I’ll get a plumber, heating and cooling guy, pest control man and my last resort an EXERCIST ! I thought I was being very sneeky leaving my old problem with the new owners, but I have now learned payback is a B**ch.
Reply
My wife and I have had the same exact problem with the sewer smell and I have fopund a solution. The smell is caused by a floor drain in the basement that has dried up allowing sewer gas to escape or a drain for the washing machine that has become corroded with sludge. Here is the solution for both of these problems.
Find all floor drains in your basement.
Flood each drain with at least 2 buckets of pure hot water.
After flooding, pour a few caps of vegetable oil into each drain. The oil will find it’s way to the P trap and create a floating seal.
Now, after following all these steps, run your furnace or air conditioning (if it is connected to your furnace) for abround 30 mins. You will smell the smell again but it is simply being flushed from the ductwork and the furnace’s plenum, but it will go away, and you wil not smell the smell anymore!
For older homes, this process may have to be repeated but I promise you it is the solution! It worked for our 75 year old home and it can work for any one of your homes!
Reply
erika Reply:
October 30th, 2007 at 8:13 am
GOING TO TRY YOUR SOLUTION.I HAVE TO ADMIT IM SCARED! THIS IS DRIVING ME NUTS! WE HAD OUR SEPTIC PUMPED 4 WEEKS AGO AND FOUND A CRACK IN A PIPED. IT WAS REPAIRED BUT EVER SINCE MY LAUNDRY ROOM REAKS!USUALLY AFTER THE WASHER IS USED.WE DO HAVE A SHOWER IN THIS ROOM THATS RARLY USED.THIS ODER IS MOST DEFFINATLEY A SEWER ODER.MY CONCERN IS THAT WE ARE ON A SLAB.I DID READ ANOTHER ENTY THAT IT COULD BE A CLOGGED(W LEAVES AND DEBRI) STINK PIPE? TO MAKE MATTERS WORSE MY HUBBY DOESNT SMELL IT!!! I HAVE A BIONIC NOSE! I AM NOT CRAZY!!!! ANY SUGGESTIONS? I JUST HOPE THAT THERE ISNT ANOTHER CRACK.TOILETS SEEM TO BE FINE. WOULDNT SOMTHING HAVE BACKED UP BY NOW? HELP!
Reply
vonn Reply:
November 2nd, 2007 at 12:33 pm
Gee, can’t men smell anything?? I have the same thing.
Reply
tami Reply:
November 12th, 2007 at 7:27 pm
You mentioned you had a shower that was rarely used in that room–make sure that the trap has not dried out by just running the shower for a minute–you should do this every couple of weeks depending on the humidity level in your home.
Reply
My house that we have just moved into has a very strange moldy smell coming from the air ducts. What could be causing it??? We are going nuts to figure out what the strange smell is. ANY IDEAS??????
Reply
I have just discovered the same problem in my laundry room. I am not sure how the furnace is connected to all of this though. THere is this awful smell that comes from the closet where the washer and dryer are kept. It seems to get worse when I do a load of laundry. I don’t know what it is but here is my other dilema…I live in a condo and have an association. I am not responsible for caring for the lawn or anything outside the walls of my home. Is this smelly problem mine, the builders, or the associations?? Any ideas on how to make the smell go away? Or explantions on how the furnace is connected??
Reply
We live in an apt. and have been noticing this same exact smell since we got home from a week long vacation three weeks ago.
We have dogs, so we thought it might be them urinating on the carpet, but armed with a blacklight we determined it wasn’t their fault.
Last night we narrowed it down to the cold air exchange vent. The smell somewhat disappears when the A/C is running, and comes back with a vengence when the A/C stops.
Our apt. people are looking into the problem right now, but I’m afraid they won’t know what to do. We live in a small one bedroom, ground floor apartment and the smell is so bad it’s hard for us to be home anymore.
HELP! If anyone has any ideas, please email me at traciatwell@yahoo.com.
Thank you!
Reply
We bought our new home 3.5 years ago. We have had many problems caused by the builder not installing drain tile around house. Water sat around and trapped under for over a year. The strongest smell at first was a very potent musty smell. After spending over $85,000 (yes we are suing) we still have an order. We have installed the drain tile and had to replace 6 feet of the outer wall because of the mod. Compared to 2.5 years ago we are about 85% better. The odor that remains is very noticable when you walk down the stair to the main floor. Evenings the odor tends to get worse. When it rains the smell is better however afterwards it gets worse. Opening windows on good days help yet on a damp eveing it reaks. The smell is hard to explain but it is a stale smell not musty anymore. Anyone with problems simular let me know. I not sure but have a feeling we may have to remove more of the outside wall.
Reply
have had several calls regarding smells like the ones mentioned. the ones i dealt with involved an odor when a/c or heating units were turned on. one case turned out to be an unused bathtub in which water in the p-trap was allowed to evaporate, another involved plumbers removing a sink to allow for storage and failing to cap the waste tube in the wall. the last was a bank building which went through an extensive remodel. the plumbers, in relocating restroom and break areas failed to properly route new sewer vents or cap off old ones. suction from the a/c units caused gases to be drawn into the dwelling places, which varied in intensity from no smell to “my god, my contact lenses have curddled”.
Reply
smelly return vents+ basement smells Reply:
September 18th, 2007 at 11:33 am
Yes we have this same strange almost musty,rank odor coming from our cold air return vents in living room and bathroom now. Have had this for two years now and can’t find the problem. We live in a older farm house and the air ducts need cleaned and our basement has a foul smell also. We have had problems with small mice in the past we found dead ones on floor by furnace and we also have a drain issue in the basement that is faulty backing up when washer is being used and then sucked back into the sump pump. I pour bleach into drain in floor but no luck! This smell is driving me crazy my husband is going nuts hearing me complain about it help please. We rent so I need advice I was going to have air vents cleaned but read the comments above won’t help. Could it be when my tolite overflowed awhile ago that the water went into the cold air return vent on the floor and is now molded? We need a soulution fast before I decide to move out. Thanks for any advice!! TB on 9-18-2007
Reply
Ann Reply:
October 10th, 2007 at 8:00 pm
My husband and I just moved in to our 23 year old house 3 months ago. Everytime the furnace fan or a/c or heat is turned ON this awefull sower like/ garbage smell takes over our house. We had the ducts cleaned and our furnace maintained for winter but the smell is still there. Tomorrow morning we have a furnace/plumber guy come in and see if he can find our problem. I don’t know what i’m going to do if he can’t find the smell source. Sell this house and move!!!??? It is very scary to see that so many people have the same problem yet nobody has a solution to it.
Reply
CBL Reply:
February 9th, 2008 at 8:15 am
I can only describe the smells coming up through our heating vents as, skunk, egg and fart! Our basement has been thorough searched for dead animals, which I didn’t think it was, mainly due to the fact the smells would come and go and I know what dead, decaying animals smell like. It was terrible. I read through all the comments and tried running all the taps in the house (sinks, bath showers)for 5 mins every other day. Plus once a week pouring either bleach or pine down the same sinks etc. I’ve been doing this for 2 weeks and haven’t had one smell so far. (I thought I was the only person with such an embarrassing smelly house, it’s good to know other people out there have the same problem.
Reply
Now a Happy Man Reply:
October 29th, 2007 at 12:55 pm
You sir (M. Stesse, reply #42) are both a gentleman and a scholar!
After living with this harsh and embarrassing odor for months, I can now truly empathize with everyone who has posted here.
Our symptoms where like many mentioned here. The smell only came when the heater was on. Plus the smell only came out of one vent the most and 2 other vents had only trace amounts of odor. All of the other vents in the house had no problems at all. (For the record, we have a central heat/air system and no septic tank, just plain urban sewage system.)
Well, we were getting ready to belly up to the bar and call in the experts. Preparing to spend hundreds with only moderate expectations that we’d ever be able to figure out, let alone fix this problem. So I thought I’d do a google search first to help me decide what kind of expert to call first.
This page was the first link google offered me. After reading through a few years of comments here documenting all of the sad (and some gross) stories… I get to Mike’s post #42 and read his experience with someone who wasn’t using a bathtub and had let the water in the p-trap evaporate. Ding! Ding! Ding!
I feel so humbled now. All I had to do is turn on the bath water for just a few seconds and our problems have vanished…
I can’t thank you enough Mike for sharing your knowledge!
Reply
A foul smell in the home like sewer gas can be caused by the sewer roof vent being filled with leaves ect… Causing the sewer gas to back up into the home.
Reply
Sue Reply:
September 30th, 2007 at 7:23 pm
I had a bad odor in the house for several winters that would disappear in the spring and summer. It was mild, and I thought perhaps it was a dead animal. This past winter it came back with a vengeance. After checking for gas leaks and dead animals, it was determined that it was sewer gas. It turns out that the drainage pipe that connects to the sewer line is under my kitchen floor (which is on a slab) and the soil wasn’t properly compacted and it settled. As it settled, the drainage pipe went with it, cracking. Right next to the drainage pipe was a heating duct, which also developed a crack as the ground settled. The heating duct picked up the sewer gas from the cracked drainage pipe and spread the smell everywhere - and I do mean everywhere - throughout the house. The smell was so bad I had to move out. Eight months later I am still working to remediate the house, having dug up the floor in order to get to the broken pipes. The sewer gas has permeated everything porous - it is in our clothes and upholstered furniture and paper, etc. It is a gigantic job to clean up. Keep sewer gas in mind when all else fails.
Reply
We’ve had this problem since the first winter we spent in our home. It smells like dead animal. Every year when temps drop the smell returns. This is not from the furnace because it’s happening when the furnace has not been on. I’ve checked the attic and found nothing (didn’t look under insulation, yet thats a job for the lazy husband) our house is on a crawl space where I’m afraid to go! Another job for the husband. We’ve been here for three winters and I’m about to loose my mind, I cant stand the smell- I’m a neat freak so the thought and the reality of my house stinking drives me nuts. Please help if anyone finds a solution to this issue. In the mean time I’m going to try to peel my husband off the couch and get him to investigate!
Reply
“When it get’s cold” - seems to be a common theme. My place to gets a terrible smell coming from behind the walls when the temp frops below 40. Is the cold air pushing down the sewer vent pipe?
Reply
My wife and I just notice a putrid odor coming from our ducts. Furnace has been off for weeks. I turned on the blower and opened the windows. But I’m perplexed. I checked the P trap. Nothing. We’ve seen lot’s of flies in the last few weeks. I’m suspecting it’s dead animal in duct work. The cold drives animals indoors. Might be that people have openings in basement that allow animal to enter via filter gap. Running AC or Heat when animal is trapped will kill it. So that’s my theory. I’m going to seal off all entry points for the duct work and hope odor never returns…
Reply
A technician from Orkin Pest control has recently assessed the extent of a cleanup of a rat and squirrel influx in my basement. He told me that the entire area is contaminated and that he would communicate to his supervisor that they need to totally replace the vapor barrier, the ceiling insulation and the insulation around the forced air electric furnace where the rats were nesting. The technician, an “insulation guy,” advised me to avoid turning on the furnace until this work is completed.
I concur. I have respiratory problems that could be aggravated by bringing contaminated dust up through the heat and ventilation systems. On the other hand, winter is fast approaching and the local Orkin supervisor seems to be dragging his feet on scheduling a clean up. The company guarantees their work. However, they have replaced the insulation twice before in the five+ years that I’ve lived in this home.
The supervisor told the receptionist to tell me, “It’s okay to turn on your furnace.”
Please advise me as to the risks of using the furnace in this situation.
Reply
I work for a new home builder in the warranty department, so you can imagine i’ve had my fair share of complaints and seen the resolve to most of the complaints, but the complaint of the odor in a certain room or entire home has eluded my company as well and we have spent countless monies on the issue. I have personally smelled this, and if i can describe it i would say it was a cross of; chemical/burned hair/dead animal. I would walk in the room with the problem, smell the odor for a few seconds then dissapear, I would walk out of the room for a couple mins walk back in and the smell would be there, now i’ve smelled dead animals… and they don’t stop smelling once you smell it, they don’t smell like chemicals. Its not sewer, no plumbing near this area, the HVAC is not the source, we had it cleaned and duct work replaced, we replaced the shelves, painted the walls, even cut some holes in the wall no smell from there.. the source is so hard to find because as soon as you smell it, it dissapears. I want to help my customers, I can only convince my superiors to do so much
Reply
We are having a very similar problem. Our home is only two years old, and we have had one problem after another. Recently, after we had our sewer drain to the septic tank replaced, due to a nasty back up in our basement, a strange sewer smell has filled our basement. It comes and goes, and is stronger some days than others. The builder, who is still obligated to fix these type of problems, seems to think we are crazy. Any thoughts would be appreciated.
Reply
Fiona Reply:
November 4th, 2007 at 6:56 am
Paul, you have my sympathy, we’re sitting with the exact same problem. We bought this house 2 years ago, it wasn’t long when we were hit with the vilest sewer stench in the basement, that would come & go, it wasn’t there all the time & we had no idea where the leak was, fortunately I happened to be on my hands & knees washing the floor in the basement bathroom one day,& actually smelled it starting up, the sewer gas was leaking through the base of the toilet. We got that fixed & thought it would be the case of “and they lived happily ever after” only to have another problem start 2 weeks ago. Sewer back up into the basement shower … turns out we’re on a septic system, that had filled up (we thought we were on town sewer), so got the back hoe in, located the septic tank had it pumped out & we’re back to freakin sewer gas stench in the basement ever since & no-one seems able to solve it. It’s so frustrating, I’m thinking it’s pure coincidence that it happened at the same time as the sewer filled up as it seems to be linked to the weather somehow, it’s not so bad on a nice sunny day but today it’s raining & overcast & I woke up to the overpowering smell of sewer gas, I suppose all we can do is keep on looking for the source & have faith that it can be fixed ! Good luck to you & I hope you get your problem solved quickly.
Reply
In response to those who have smelled a “skunk”like smell coming from their vents….we just recently had that problem in our condo and came to find that it was actually our neighbor’s furnace….the pilot light went out when they turned on their heat and it was actually gas!! I read that because gas naturally has no odor…many companies add smells to it so that people will recognize that there is a leak…and low and behold…alot of times it is a “skunk” smell that they use! So beware…it may be a gas leak you are actually smelling!
Reply
Just a friendly tip–if you ever smell a sewer smell in your home one of the easiest things to check are the traps. You can do this by running the water at every sink and or shower which will fill them up. Traps can dry out easily if the sink or shower is not used much so remember to run the water in unused plumbing every couple of weeks. Also if you have floor drains or an unused washing machine hookup these too can dry out–so pour some water down the drain. Hope this can help someone–I have had this problem myself and it is so simple to fix!
Reply
Anon Reply:
November 22nd, 2007 at 10:09 pm
I noticed the sewer smell this afternoon and when I ran water down the drain it went away. I use the sink twice a day so I don’t think that constitutes “unused” so am still curious about why it started to smell today. Will get my plumber back to check it out as it was all redone two months ago - when the furnace wasn’t running! Anyway, two hours later, when the furnace started again, the smell returned and once again disappered when I ran water. It’s colder and rainier than it was last week, perhaps that has something to do with it? I will also have the condo assoc. check out the vents on the roof - don’t want to spend the winter with this!
Reply
we just moved into a house and at first the laundry room smelled terrible, like cloths that have been left in the washer for a week. but now it is spreading throught the house, it was so bad this evening it actually made me sick. We have an electric water heater and baseboard heat i am trying to figure out where the smell is coming from? I think it maybe the water heater but not sure???
Reply
Our home is only three years old and I have been noticing a faint sweet gassy odor periodically upstairs. After we moved into our home we discovered that 40+ years ago our lot was used as an unofficial dumping area. God only knows what may be in that soil, and hopefully it is only hard debris, and not chemicals. Through my research I have learned that certain chemicals often could leach up and often the gasses are noticed on the higher level of the home. Hopefully this is not the case for my house, or yours, but nonetheless it is worth having checked out by a company experienced in these matters. Good luck to you all.
Reply
For at least 4 months, we had noticed the musty smell that many are referring to in our home as well. We had many theories as to where the smell emanated. When we acted upon them, the smell seemed to go away, and then would pop back up another day, in another room.
Bottom line: It turns out we had several inches of standing, putrid water in our crawl space below our home. A sewer line (it was actually a pipe that both bathwater AND sewer water drained into) had busted. Naturally the water had to be pumped out. Now my husband has the honor of going down into the catacombs and replacing the busted pipe! It’s that, or pay a plumber an est. $3000 to do it!
2nd Bottom line: Check your crawl space if you have one!
Reply
Paula Reply:
December 21st, 2007 at 3:51 pm
Did that work? Did it go away? We suddenly have had the same problem. We have a old furnace and the ac/heating guys have been out here twice and can find nothing wrong. The critter control also in emphatic that we have nothing dead. (we’ve had them out twice. ) please tell us how your issue ended?
Reply
If the smell is reminding you of dirty socks, we experienced this several years ago…..it was my parents house. I told them about it, and when they went back to the house (summer house) they had the heating pipes checked out - there was a leak in one of the pipes, right where the dirty sock smell was coming from.
Reply
My wife and I were actually awaked by a horrible smell this morning and we looked all over the house for the source. When I opened the 1/2 bathroom door on our lower level, the funk would knock you to your knees. It had been at least 3 weeks since the sink had been used in there and thanks to our heat pump and winter weather, the house was dry as a bone. I guessed the water in the “P” trap had evaporated, so I turned the water on for a few minutes and we both noticed the smell lessened almost immediately. That’s been 4 hours and I’m getting ready to take a ride home to see if the smell is gone permanently.
Reply
For the last two days we have had a strong smell coming out of our vents. First it was just in the vent in the office. The a bathroom. Now it’s everywhere.
I went into the crawl space and everything looked fine. . No smell under the house. I think an animal somehow crawled into the duct work and died.
We have now blocked all the vents which helps to a degree. We’ll wait until mid March and if it is still a problem, we will start replacing the duct work.
Reply
Possible solution — We’ve had a smell in our basement for the last week. Smelled like urine but we have no cats and have lived here for 4 years. House is 15 years old and has 2 stories plus a finished basement. I had smelled it on and off before but now it was really bad. I read through all the posts here and decided to try turning on all the faucets on full blast with hot water — every one of them: sinks, tubs, shower even the washing maching. I also flushed all the toilets. I did this for 10 minutes. When I went back upstairs all the sinks (4) and the tubs (2) had brown gunk in the bottom. None of the other sinks had anything. It seems better but it has only been a few hours. If I was doing it again, I would have dumped a bucket of water down the basement drain just to be safe.
Reply
After pouring lots of chemicals down an underutilized sink, the smell has dissipated considerably. I do believe that my heater was picking up a stench from the pipes in my kitchen….
Reply
Our smell smells like a musty hot iron, like the furnace smells like at the start of the winter season but very much stronger, but does not smell like anything rotting, or sewer gas. Gas company says they can not find anything wrong.
Symptoms: Once a day to 8 times a day, usually when it is 10-20 degrees colder outside than normal(during winter) for aprox 2 min a musty hot iron smell drifts out of all of our vents. (no noise or air pressure) next we hear the small vent fan start up, next the furnace can be heard igniting. the the large blower starts up and a blast of super hot, musty hot iron smelling air comes out.
A normal cycle for our heater is as follows, the small vent fan starts up, then the heater ignites and then the large blower starts up, no smell and this whole thing takes 22 secs.
PLEASE HELP!
Reply
I had to laugh, hoping I’m not laughing too soon, but I’m giddy with relief and the smell is gone.
We get a dead animal smell every winter for the last 5-6 years for about a week. Untraceable odour, sometimes methane/sewage smell but at it’s worse, what I can only imagine is a dead mouse or squirrel somewhere in the walls. Always upstairs, always winter- usually during a cold snap of minus 25 Celcius. We’ve had a furnace repair check, plumbing check and city water experts, adn animal control try and identify the smell. No luck and smell goes away on its own.
Yesterday as I’m leaving for work I notice a strong bathroom odour at the front door. I check the upstairs bathroom thinking someone didn’t flush but not so. Arriving home late afternoon the smell is worse. (Husband also on the couch and unable to smell the offensive odour at all) The smell is coming from our daughter’s room. She can smell it too. I make her clean her room, sure we’ll find a dead chicken carcass under her bed, or a forgotten lunch in an old knapsack with rotting potatoes and moldy meat. Now we have a full set of dishes, glasses and cutlery again. Next theory is that there’s a colony of mice that have been living off the crumbs in her room, and they have all died and are decoomposing in the hot air vent. The smell is coming from her room, one wall, the hot air vent. There is no evidence of mice dirt but I remove the vent cover and hang a mirror on a coat hanger and use a flashlight to see the duct work that runs under her floor for 3 feet. I fully expect to see a rotting squirrell as by now the smell is unbearable. There is nothing. I even lower the digital camera and take flash pictures of the vent. Then I vacuum the vent, fully expecting to hear a large mouse plug the nozzle and then suck into the cannister, just incase the camera and mirror are lying. Husband has gone to bed and daughter shows up to ask me what we’re going to do about the smell in her room. “Haven’t a clue…close the door?” Truimphant that she’s not to blame but inable to argue with my solution, she sleeps on the living room couch. I sleep in the family room. When I wake up at 5 am with a headache I check her room, smell still bad. Downstairs in the basement I check the internet. The number of blogs is staggering. Sorry to see so many unanswered frustrated people, the number of unsuccessful solutions and the cost. I also sense it is a sewage related problem but dead animal is also a certainty from the smell. We dont’ have a floor drain in the basement. Then I realize we have a pair of laundry tubs that are dry and full of pots, paint brushes, summer crocs that need cleaning.
I ran water in them for about a minute. I think and have my fingers crossed that the smell is gone. I can’t believe the basement drain could cause a smell in her room but I think it’s gone. Will have to wait until noon when daughter wakes up to confirm. Thanks for the direction. Saved days of discomfort, frustration and money.
Reply
It’s amazing how many replies one can get. I have the same problem and it’s a dead mouse. I don’t have to have an expert or an incompetent technician tell me about dead-mouse smells. When I was younger, my sister had pet mice. One time my brother took some of the baby mice into my car and one escaped to never be found until it started to rot. I put up with the smell in my car until I could not stand it anymore. I could not believe how bad it smelled since the mouse was tiny (it was a baby mouse!). Then I had the idea of taking my fox terrier dog into my car who found the mouse in no time. I have never forgotten the smell. My problem is not identifying if it’s a dead mouse (it is!) or if it’s in the furnance or vents (it’s there!). My problem is trying to figure how they get in there. I have never seen evidence of mice in my basement or in my house (but I know there are plenty of them outside). This dead-mouse ordeal happens at least once a year. My house is 5 yrs old. I looked at the vents outside but none of them actually lead to the furnance directly. I have reinforced the mesh that covers these vents (I just did it thes very last time after the odor started). My second theory is that there are mice in the basement (no droppings found though) and somehow the mice get into the furnance. The third theory is that a mouse dies in the basement and then the smell travels to the furnance intake. This mouse ordeal seems to be a common problem but I have not found any helpful information on the internet yet that would help me prevent the problem. Everybody talks about the smell. Yes, it eventually goes away (I know after having the problem several times already). What I want to know is how to prevent it for good!
Reply
Sewer people & electric filter people: please go to your own homepage. This is the page for the dead-mouse in the vents problem.
I think several people have described the smell as a combination of moldy, putrid smell and a bit skunky. I think this is a pretty good description. It has a hint of a skunky smell but very musty. I know it’s not truly a skunk smell. One of my little Yorkies got sprayed by a skunk last summer(his head was drenched). We bathed the dog for two hours with tomato puree (I did not have tomato juice) and shampoo. The smell lingered in my house for days and the dog’s head smells for over a month despite of a haircut and many baths. So I do know well how a skunk smells. Anyway, I don’t how people can’t distiguish between a dead animal odor and sewer.
By the way, since I have experience the dead-mouse many times in my house, I can tell you that it may go away in a week or up to 3 weeks. I guess it dpeneds in the size of teh animal and the rate of putrification. You can certainly see a spike (sometimes a couple of spikes).
I now suspect the dead mouse might be in my drier duct since the flap outside cannot prevent mice from geting in. I just installed a mesh. We’ll see.
Reply
Jill Reply:
June 3rd, 2008 at 2:04 am
Does a dead rodent smell like wet dog? Or like a burning smell when you first turn on the furnace in the winter? Because that is the smell that is coming from my bedroom and it smells worse around the vent area.
Thank you
Reply
i to have this awful smell in my walls and of course i remembered my loving husband flooded my bathroom by leaving the bathroom sink running , he was takeing a shower at the time also. and my heating ducks to my furance is on the wall close to the floor. i dont know but i think this awful smell is insulation that got wet im just guessing cause i dont really know what insulation smells like when its wet but it funny i never had that smell until water got in and speeped through my wall ,aslo my wonderful sis flushed my toilet and again water went every where again so i do belive it is insulation cause it is gross does smell like a dead animal. of course hubby cant smell it cause he works with deisel all day and thats all he smells
Reply
Well, unsurprisingly, I too have a smell. It actually smells like skunk or fox spray. I’ve never smelled a skunk, but there is something distinctly musty about it.
The smell started in our bathroom. Like many on this forum, my husband and I were awakened by the stench. I actually thought it was some dirty laundry behind the door (I was pretty groggy) and shunted said laundry to the basement. The next day, I bleached the whole bathroom, etc. etc. etc. The smell dissipated.
Last night, however, the smell was back. I don’t think it’s dead animal; I think that smell would be more continuous, especially if it had died in a heating duct. However, a couple of days ago, I went outside and smelled the same skunk/fox smell OUTSIDE. Last night, I thought I could smell the smell outside as well.
I wonder if it’s not an animal spraying in the area. Can that smell leak into your house? This morning it was everywhere–bedroom, kitchen, even garage. (The garage is not heated, but is attached to the house). As the day has progressed, the stench hasn’t gone away.
I have a plumber coming tomorrow on a separate (or maybe not?) problem. Anyway, has anyone else found that it’s a living animal spraying around the house?
Reply
We have a bad smell coming from the Air intake for furnace that is vented outside. It causes our 3 season porch to really stink. What can we do?
Reply
We have a very similar problem that we have been trying to figure out.
Our theory this evening, is that the cause is the condensate drain on the A/C. It is draining ‘down stream’ from a sewer trap, so foul air is coming back into the air handler.
Reply
Vicki Reply:
June 25th, 2008 at 12:22 am
Mike … I think we have the same problem as you do. So what is the solution (to the A/C condensate drain draining downstream from sewer trap)?? I have just poured bleach and water into the condensate drain and it seems to have helped some. This is so frustrating!
Reply
A good candidate for the origin of such a ‘musk’/skunk like odour is rat urine.
I’ve had rats in the attic of my house for almost a year now but have killed most of them. Problem is, the stench of rat urine lingers on. When it’s windy outside, the stench is pushed downwards into the living room from the attic above. It smells somewhat like pig urine. It has been there for months now, I wonder if it ever will break down by itself or be decomposed by bacteria? Do anyone know how long it will take for the smell to dissappear after the rats have left?
Reply
I was laying in the bedroom my head position close to the wall. There is an Heat/air vent on the floor beside the bed. It was very quiet in the building. My girlfriend was in the kitchen and turn the facuet on, right at that moment a rapid dripping sound occured within the walls. the it hit me light a Freight train that smell, smell that smell…we as people probably dont live as sanitary as we really should in order to constantly stop bombarding our immune systems and creating our own health problems…it has to be something rotting some natural as it smells like sulfurous odor which occurs naturally during composition breakdowns…just a thought…remove All dust Fibre contaminants Wash, rinse repeat…have only sterile surfaces, stainless steel etc…
Reply
Try Rataway spray from Rataway.com
It is used to stop Rats, mice, squirrels,raccoons from nesting& chewing on wires and ductwork in heating & air conditioning systems.
Reply
I am having a paint like smell come from the vents right when the furnace kicks on. It is driving me crazy and making me sick. I have had the gas company and h/c people out and they can’t find anything wrong. Please help…
Reply
I am having the same problem. It started in my bathroom. I held my camera down in the heating vents so I could see. It was a dead rat. I got him out with the vacuum. I love my kirby!!!!! I have vacuumed, pulled a sheet soaked in bleach in the vent (with a tool called a snake) and had fans trying to air out the rooms, my bathroom and bedroom. I can still smell it but I do not see anything. How long can that smell linger? I put a pound of baking soda and the vacuumed it up thinking that was the smell.
Reply
I, too am having a paint smell coming from my vents. To be exact, it smells like paint at first and then turns into an indescribable musty smell that literally makes me sick to my stomach and makes my head hurt. Fiance recently stuffed the basement ceiling full of insulation. Today after reading all of these posts, I think I noticed that the smell is worse when the washing machine (which is in 1st floor laundry room) is running. I have electric heat pump so it has nothing to do with natural gas.
Reply
So, I’ve read it all and still nothing compares to my on going problem. No one can figure this one out.
I have a heavy smell in the basement wall under the kitchen.
It smells like someone is cooking a ham. Could be similiar to someone cooking bacon but more like a ham.
It gets worse in the cold winter months. And it’s been doing this for years. It’s getting worse!
I’ve torn a hole in the wall where the kitchen pipes go into the basement (basement is completely finished) the pipes are dry, the instulation is dry, the plastic barrier is dry, but the smell is very bad here. Under the kitchen sink is dry, and it does not smell under the sink. This wall is on the outside backyard and it is a town home. Though the neighbours are different so I don’t think it’s there cooking smells leaching through because it’s the same smell. I do very little cooking, and rarely use the oven, mostly raw food diet. I am on a sewer line and have had the city inspect the house, they say it does indeed smell like a ham, but not sewer gas, not a dead animal smell either, but he did find the smell from that corner of the basement. The drain pipes for the kitchen are here and so it the shut off valve for the outside garden hose.
It getting worse and it’s driving me insane!!! I want to rip out the basement walls to see what’s there, but who has the money/time to do that. A neighbour came over and I asked him to describe the smell, he again says it smells like someones cooking a ham. But a musty kind of ham smell is starting, so I’m wondering if the wall is breached because when we cut the hole in the bottom of the drywall to take pictures there was quite a cold breeze coming in from the outside wall, and there is a window not far from that.
The roof was redone 3 years ago but the smell was before that and is still getting worse. I guess I have no choice but to rip out the dry wall.
Anyone with this problem? Is there wood rot or instulation rot on the outside wall? Do you think the kitchen drain pipe is broken under the house foundation, the town home is 4 stories high, the ones with 3 rooms on each floor.
It’s a tall long town home. The basement is a 1/2 basement, the crawl space the is clean and dry and no smell, the drains are good, no smell. It’s that outside wall, which is cold and smelly. It’s 18 feet long with one window. The floor is dry and clean and I put down a click floor last year, no water, no wall leaks, no dampness, the house is actually very very dry. I also read that very very dry is not good either because that means outside leaks are getting in. The house smells like a restaruant, but it shouldn’t. I’m also a clean freak, so the house, the fridge, the garbage, the garage everything is spotless around here. The house is 17 years old, new roof, same med efficiency natural gas furnace, gas water heater rental is 4 years old. Water doesn’t stink or smell bad, toilets have been resealed and there are no leaks. the main bathroom is on the 4th floor and it is dry and there is no smell here. I also rarely cook meat. Maybe once a month if that. The house is in Ontario Canada. The temperature today is -21C and it’s a dry cold. Seems to get worse in the winter, though I’ve come in the house in the summer and it’s pretty bad. I can put up with it and friends and visitors think I’m cooking something wonderful, “MM what are you cooking a stew” I just say “yes”
Reply
2roads Reply:
January 16th, 2009 at 7:25 pm
Okay here’s something to try… cause I just read them all too because I have what I would call a sweet smell pumping through mine like a good beef stew. Get a gallon jug put about a quart of Vinegar in the bottom and fill the rest with hot water. Pour some in all your drains including the washer hook-up drain and the utility room or basement drains.
It was -29 degrees F in Iowa last night and we’re looking at a heat wave tonight of -16, so it must be something connected to the chill. It seems to be smelling a little less at the moment, so I probably need some more hot water to pour down the drains.
Reply
Do you have a humidifier attached to your furnace? A few weeks ago, we noticed an odd smell coming from the vents. We had a furnace guy check it out, and he could find nothing wrong. He did, however, have a pretty good theory:
It had been unseasonably warm a few days before we noticed the smell, and the furnace had not been running. Also, it hadn’t been very dry, so the humidifier had not been running for several days.
The morning we noticed the smell, though, it had gotten quite cold and dry again, and both the furnace and humidifier were running.
The furnace guy said the smell was probably due to the fact that the humidifier hadn’t been running for several days and that there was nothing to worry about.
Since the first episode, the same pattern has repeated itself twice more: Unseasonable warmth — no furnace — followed by the return of cold and dry weather. And twice more the smell reappeared.
All three times, though, the smell disappeared after one cycle of the furnace/humidifer running.
Hope this helps.
Reply
Hi all,
There seems to be a few different problems in the responses here. Ours is a smell coming from the air ducts only when the furnace/AC/fan-only is running in our 6yo house (we are the second owners) in Wisconsin. I describe it as a musty swamp smell that’s a bit sweet. My wife agrees, but not about the sweet part.
Me and my 5yo daughter have rather severe environmental allergies so the AC runs all summer with the house closed. When I first smelled it, I attempted to clean the a-coil myself (dumb idea). We then called the HVAC guy, who bought a bottle of acid-free anti-fungus coil cleaner on his way over – I don’t think they’ve dealt with this type of problem before. It seemed to have helped, but the smell soon reappeared just as strong. It hit my nose immediately upon entering the house and my allergies (alterneria mold among them) kicked in soon after.
After some more internet “research”, I installed a Honeywell over-coil UV light. Again, temporary relief. The next shot was another UV light in the return duct. Same, but when the light’s on the smell is definitely muted. I think we’re on to something here.
The latest is that I noticed the smell seems to get worse when the furnace fresh air intake duct is open. I just pulled off the grille from the outside and don’t see anything but dust/dirt in the flexible duct, but it’s something we’re going to mention to whoever we get to take a look.
That’s the big question now. Who do we call? HVAC? Mold treatment? How do we find someone that can actually fix our issue instead of the trial-and-error that I’ve been doing?
BTW, we have an Aprilaire 5000. I unplugged the electronic part last year when the smell first surfaced. I notice that the smell has permeated the paper filter. Changing the $40 filter doesn’t help, either. After seeing the amount of dust that gets around the Aprilaire, I can’t say I’d recommend one.
I’ll try to remember to update this WHEN the problem is solved. SOMEONE has to know how to find it, right?
Reply
SUCCESS??!???!!
My wife ran our three bedroom air cleaners on high and vacuumed and cleaned the whole house today with the furnace fan off to help with the smell, with only a little temporary success.
I looked up a local mold expert on the IICRC website I listed above and talked with him. The cost, $350 to show up and $99/test (and I don’t doubt it’s worth it for quality work and this guy seemed to take a scientific approach to remediation), caused me to take one more stab at it.
I disconnected the flexible hose from the furnace air return, being careful not to let it drop to the floor of our semi-finished basement, then turned on the furnace fan — NO SMELL! $12 for 7′ of 4″ rigid vent tube later and we’re smell free! Hopefully for good.
In replacing the flex, I kept the existing rigid diverter. I did notice signs of excessive moisture on it, with some of the steel parts rusted and what looked like an effluent/moisture stain in the dust. When I did an initial rinse of the part in hot water, there was the faint smell of The Smell — I could have imagined it, but I don’t think so. I then used a heavy dose of Lysol (I figured that if the CDC uses it to kill ebola, it’s good enough for me), another rinse, towel dry, air dry, spot application of WD-40 where needed and an isopropyl wipe of the excess.
I opened the diverter for full access to outside air, and noticed within minutes that there was condensate on the new intake tube! This is in a 65F basement with 38% relative humidity and it’s 40F outside — it doesn’t make sense to me. I’m going to leave it for tonight since the kids are in bed. Tomorrow I plan on plugging the intake from the outside with a cloth, taking a hair dryer to heat up the new pipe, then insulating the hell out of it.
I don’t know if this is good or correct or what, but it’s just what I’ve done. I’m just happy that The Smell is (HOPEFULLY) gone now!
Reply
WE HAVE BEEN HAVING AN ODER IN OUR HOME. IT JUST OCCURS WHEN THE WEATHER IS WARM OR THE EARLY EVENING. IT MOVES AROUND THE HOUSE, IT SMELLS LIKE URINE. WE HAVE SCRUBBED AND CLEANED AND WE STILL HAVE AN ODER. WE HAVE HAD THE AIR CONDITIONING UNIT AND DUCTS IN THE ATTIC REPLACED AND WE STILL HAVE THE SMELL. WE HAVE HAD THE STOOL SEALS REPLACED AND CHECKED THE VENT FROM THE SINK. WE HAVE RAISED THE VENT PIPE ON THE ROOF OF THE HOUSE AND WE STILL HAVE THE ODER USUALLY IN THE EVENING. THE NEXT MORNING THE SMELL IS GONE. I RECENTLY HAVE HAD THE NEW DUCTS INSPECTED AND FOUND NOTHING. OUR HOME IS 40 YEARS OLD AND WE HAVE NEVER HAD A PROBLEM SUCH OF THIS. WE DO HAVE A SEPTIC TANK THAT IS VERY OLD. IT IS CONCRETE AND I HAD IT CLEANED OUT THINKING THAT WAS PROBLEM. WE HAVE HOT WATER HEAT AND TO MY KNOWLEDGE THERE IS NO FILTERS IN THE FURNACE. WE NEED ADVICE.
Reply
OK,
I too, like evryone of you, have been having the infamous skunk smell in my ducts too!!!! GGRRRR!!!! The smell started in my office, with no rhyme or reason, and seemed to be worse on days I did a lot of laundry. I thought it was my new front load washer or the pipes, and was all prepared to get rid of the damn things! The smell was faint in the laundry room. I had just had a new furnace installed and wondered if it was so powerful as to “circulate” the stench. Then I noticed it coming from the vent over my craft table in the basement when the heat first turned on. (I hadn’t done laundry for two days at this point) I have since discovered the smell in some (NOT ALL) of my ducts in the house, (by getting on my knees and sniffing the vents - my husband is laughing histerically at me - he can’t smell it!!) so thought maybe I had a rodent dead! Had the vents cleanded and deodorized, and still - SKUNK SMELL. Hot water tank gave up the ghost, so we thought maybe the smell was coming from it or leaking gas pipes. New tank, still smells. So I too, am going crazy. I feel sick from the smell and I just want it to go away. It all started with the new high efficiency furnace installed beg. of March! So if anyone has that “light bulb” idea, please would you share it???
Reply
Terri Reply:
May 1st, 2009 at 8:24 pm
Me TOO! Thats when the smell started here after I had a new high efficiency furnace installed last Nov. Please help us!!
Reply
Going Crazy Reply:
May 9th, 2009 at 4:36 pm
Terri,
I don’t normally do this, but…….
I don’t know if you will visit the blog on the web regarding the “revenge of the smelly ducts” - so I wanted to share with you something pretty interesting.
Our plumber came in and actually smelt what I was talking about, found a rubber gromet that is put in place to keep the wires from touching the hot metal and it smells like skunk!!!!
My husband is going to make sure there aren’t any more gromets in there - but I think this is the problem. I knew it happened immediately following the installation of our new furnace.
I hope this helps you too. What a frusterating experience - I’m sure my husband thought I really was crazy!
Go looking for anything rubber - especially if it touching anything warm or hot. Good luck, I hope this helps you too.
Karen
Reply
OK, people!!!! Cross your fingers………… We found something!
I wanted to post this, because it has been the most frusterating thing to try and find out WHY my furnace smelt like skunk - nothing more - skunk!
My plumber stopped by and he smelt the stench, and located where he smelt it!
It is a rubber “gromet” that keeps the wires from touching the metal (OK, I wasn’t here when he did this so don’t know exactly the location but…)I smelt the rubber and THAT’S THE SMELL!!!! My husband is going to go through the furnace with a fine tooth comb to determine if there are any more causing grief! I knew the smell started the minute the furnace turned on!! At one point, I thought the tin basher dropped his bag of weed in the furnace!!! (But that would have quit smelling once it significantly dried up or “burnt” off!)
Just thought I would post this and share my story.
I really hope this is the last of the problem!
Bye
Reply
I have had this unidentifiable “skunky” problem for months. In the last 4 days, I have simply turned the Fan ON on my thermostat. I have not run the heat or a/c, but simply the fan. I have not smelled anything in days. I hope this helps some of you.
Reply
A couple of days ago we had a guy come out to give us an estimate on a new furnace. He showed us how the old one was blocked and the gas was “rolling” on the burner. He was a nice guy and knew we were not ready to make a purchase. He recommended we turn off the gas and extinguish the pilot to be on the safe side. Now, we have a smell that reminds me of burning dust or rubber or an electrical fire. The smell is not in the basement where the furnace is, but can be smelled by the vents on the first floor. Should we relight the pilot? It has been rainy and humid the last couple of days. If you have an answer, please feel free to email me at pallison@twcny.rr.com. Thanks.
Reply