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
I have been following this web site after searching for an answer for a moldy dirt like smell was coming from only one ceiling vent in my home. It was not constant but when we did smell it – it was pretty bad. I call a reputable HVAC company and after inspection, he determined that when my 10 year old home was built, who ever sprayed the texture on the ceilings did not cover up the vents allowing the texture to harden on the vent boot. There was a blackish brown mold on several other ceiling vents as well bout we could only smell the one vent in the kitchen. I cleaned it with 50/50 water and bleach. I scrubbed the metal inside and gently brushed the actual duct as the mold was only an inch or two above the sheet metal boot. I then sprayed some Lysol mold allergen killer inside as well. I then washed the grill with my mixture and turned the furnace fan switch to on – not on heat or air just the fan itself. I was told by the HVAC guy that this would help dry off the insulation that I had to scrub also (at base of boot as I had to remove the sprayed texture as over the years the condensation settled in the overspray and it turned moldy). We thought all was well. Then it came back in about a day or so. We had decided after looking at this web site that we may simply be doomed! We discussed calling the HVAC back out as maybe I did not get it all. We turned on the heat and I took off the grill and we only smelled fresh air!! As we sat at the table in disbelief, my wife (for whatever reason) put her nose to our wood kitchen table that was right below the vent. Lo and behold she said it’s the table! Long story short, our less than 1 year old wood kitchen table had been permeated by the mold spores (or dirty dust) for the while. The top of the table stunk, the backs and tops of the chairs stunk of the same smell. We used several cleaners to clean the table as not to ruin the finish. The smell is gone and my marriage is intact!! Apparently the junk just kept blowing on the table and was absorbed by the table being somewhat porous. So I would encourage anyone who has cleaned there vent and/or ducts out and the smell returned to smell any furniture whereas the vent could blow the particles on.
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We have had the same problem since installilng a new furnace a month ago. We cleaned everything out of the area where it was coming from and there was nothing moldy or musty. I then kept record of when it was most prevalent only to find it was usually when it rained. The furnace salesman told my husband he should move his wood pile so as not to surround the venting – we did make allowance for this and built the woodpile up around the venting. However, it is now considered that possibly the smell was coming from the intake pipe outside wood has a moldy odour and this was being drawn in the intake pipe on rainy days. Since moving the wood pile we HAVE NO PROBLEM. The smell is gone.
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I think the pipes or some building materials could stink, especially the ones made in China. Once I bought a pair of brand new shoes at a good store, Ingledews in Canada. These stank up a big area in the house before I found out where the odor was coming from. I kept the shoes outside for the whole summer and in the garage for another half a year before the stench disappeared. I told this to a relative in Hungary and lo and behold she said she threw away a pair if made in China shoes. I just wonder if some building materials, especially nowdays that so many things come from recycled material and very low quality places, might start to let out stink due to heat, moving air and God knows what?
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I have been having the same kind of problems in my home with air quality which seems to involve my central air . I have found it to be embarrasing and annoying my home was built in 1928. I have tried setting the vents in different directions but unsuccessful I feel like the air quality that is being produced is poor. My Cenral air unit is only 3 years old which performs fine minus the smell. I have had two plumbers come out to evaluate piping which is fine. Not sure what else to do except for opening all windows and buying an industial fan.
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I reside in Brooklyn I have lived in my apartment for 6 years. My apartment is heated by oil. when my heat came on NOV 2011 I thought I would throw up there was a smell emitting out of the steam pouring out of the radiator. I immediately called my landlord who had no idea where the smell was coming from. He turned off the heat because the smell was so bad. The smell went away in 20 mins. Thank god is has been warm in NYC this winter., until last night. The temperature dropped drastically and I needed heat. The landlord turned the heat on and once again I thought I would throw my guts up The smell that came out of the radiators was putrid. My landlord has no idea how to get rid of this smell. Please someone help me so that I can tell my land lord how to help me winter has returned with a vengeance and i need heat.
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Did you ever find out what the smell was? I have the same smell coming out of the cold air return. It is upstairs in the Master Bedroom where the cold air return is in 2 from the hallway & master. The furnace is in the laundry room closet across from the master if this helps. There is no basement, only a crawl space. Our house is almost 3 years old.
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My favorite product to date is Room Shocker. This stuff really works on everything such as: carpet, furniture, and clothing. It is so interesting because it works like a fumigation bomb, but for bad odors. This stuff kills the odor right at the source and the smell never comes back. You have to get Room Shocker to help you out with your odor problem. Check it out at http://www.biocidesystems.com/roomshocker1.html
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Patricia, we are researching the same type of smell in our vents – Did you find solution? We’re considering having our ductwork cleaned, but I’m seeing several comments where it did not help other homeowners. Thanks for your input.
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Wow!… after reading entire post of comments I was freaking out last night with that sweet skunky smell.I turned the furnace on /off just running the fan, don’t have an electric air filter so can’t turn that off , but we do have a AprilAire humidifier, so I turned that off and smelled it. That wasn’t it. I went and smelled every vent, finally concluded that the odor was the strongest in basement where furnace is located. Checked to see if pilot light still on and working… yup, everything good there, so I went outside and sure enough I smelled a skunk big time. It was the strongest by my Fresh-Air Intake Vents. Whew! problem solved. Woke up this morning and smell is pretty much gone. Anyway, I would check around your house for a skunk or dead animal(s) first before spending hundreds of $$ on a plumber or HAVAC tech. I live in the Northern Subs of Chicago. We have had a real mild winter so I’m guessing rodents are more active since it was and has been in the 40′s. Hope this helps!
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You probably have a dead mouse, rat, or other animal in your vent. I live in a rural community, so I have unfortunately gotten accustom to having to bait for rodents every couple years. The smell will dissipate after time on its own, as the carcass dries out. The fact that the smell goes away when you run the furnace supports this, as it has happened to me. The smell will eminate through the air return through your air ducting when you don’t run your furnace, but disappears when you run it. I usually use scented candles when it happens to me. I always thought that is was better to smell that, than to deal with live rodents running around…
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Sour Musty Smell: Sure hope someone can help. We are going crazy and getting sicker in this house…hotels are becoming an expensive and inconvenient alternative. Scratchy sore throats, migraine headaches, brain fog, fatigue. 6 year old house, we’ve been the sole owners. Our smell started in Master Bedrm about 3 months ago. Turned off UV Air Purifier that was attached to air handler (per other posts). Cabinet that houses air purifier had same musty smell, only 10x worse. Air purifier supposedly state of the art, with 6 UV bulbs, a 4″ Merv 13 filter, and a 1″ carbonated metal honeycomb filter. Paper filter is changed 2x yr (even though its supposed to last an entire yr), all 6 bulbs & metal filter are changed every 2 yrs., per Lennox recommendations. Turning this off did not help . Had A.C. checked by 3 different companies: coils are spotless, wall board that lines air handler is clean, ductwork in attic checks out fine, no mold or mildew anywhere. We have AC maintenance 1x year. Had Blower Door Test by utilities company (I highly reccomend this, at $35 you get alot of info on home’s energy usage). Duct work in excellent shape–no duct leaks.
Concerning Main A.C. return, located in hallway ceiling: Vent was removed during AC guy’s visit, he and I were in garage, AC was running. After about 20 min, walked back into house and upon entering hallway the musty, sour odor just about knocked us out. Reinserted return vent and smell subsided. Smell travels through house, sometimes worse in certain rooms, or non-existent in certain rooms. Smell is definitely in the AC/Return system, but we dont know where its coming from. 2 roofing companies checked roof for leaks and attic for evidence–all dry and fine. Had professional ozone treatment which sucked ozone through whole house. Now house smells like musty, sour ozone. Ran water down both bathtubs as they are rarely used (after reading posts on dried out p-traps), but dont think it helped. Really at a loss at this point. One interesting variable: Approx 3 wks prior to noticing smell, had exterior of house and roof pressure washed. Noticed afterwards on INside of bedrm windowsill (window had been closed) several puddles of water. Pressure must have been intense enough to get through but have to wonder if water somehow got into wall space. (smell did start in this room). We have the E-Walls where its poured concrete with foam in between. If water got into foam maybe we have mold? No dark spots on wall or ceiling though. ANy suggestions by anyone out there would sure be appreciated.
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We moved into a new construction home late September 2011. In early October 2011, we started to smell a sewer gas like smell in a 2nd floor bedroom located in the vicinity above the furnace, air conditioner, water heater and 3 external exhaust lines. This smell is also evident at the top of our basement stairs. The smell disappeared entirely in the first week of November (when cold weather stayed). The first week of March (4 months later) the foul sewer gas like odor reappeared after strong winds and warmer temperatures. The builder said that maybe the house is too tight and installed a 6″ fresh air return line from the bottom of the first floor down next to the furnace area in the basement. This did not fix it. One week later we did a peppermint test on the plumbing lines. We detected faint peppermint smells in a few areas right away and stronger peppermint smells in the basement only the following morning. I am at wits end, because the smell is too strong to sleep in the room. We did check all the traps, toilets, ejector pit, etc. too with no success in finding the cause of the smell. I am thinking of doing a smoke test next. What do you think we should do next? One last thing, there is a pvc line that stops in our attic and doesn’t go out the roof. Any correlation to the smell? The pvc line doesn’t smell every time we check the attic, but my gut feeling says this line should be on above the roof.
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Just finished inspecting heating system surching for source of foul odor comming from hot air ducts. The ducts are clear of decomposing furry creatures but there is an orange colored deposit on the out side of the heat exchanger. It smells like decomposing organic matter. My furnace guy says there is a manufactures bulliton on my 16 year old furnace heat exchanger and are offering a replacement credit. … how about it?
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We have the slight skunk oder in our living room which is on a slab. We have baseboard heating. No septic system. Started about 3 months ago. It isn’t constant.
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that is awful. I hope that you could assess it right away
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Hi,
In March after a good rain we had a sweet skunky smell under our bathroom sink. Had plumber out not sewer or plumbing issue, had exterminator come out not dead animal smell. Finally went away. Now its July after a good rain same smell in guest bedroom REALLY strong. I could smell on wall near baseboard near a electrical socket. Called a different plumber her said not a sewer smell, called HVAC guy he looked everywhere no dead animals nothing can get into walls (we are on foundation). Its been over a week now I have tried everything its driving me crazy! Could Skunk smell last that long and why would it spray that outside wall No vegitation there only rocks! Could Mouse feces smell like that we have had some field mice.
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