Latest Discussions : HVAC

barbjeff

06:44AM | 02/06/04
Member Since: 02/05/04
1 lifetime posts
Whenever the furnace goes on, I smell a strange sweetish odor coming from the vents which irritates my eyes and nose. I have a service contract and the company sent out a man who walked around the house with some "detecting" tool. He said there is no gas leak, which of course I knew since the smell was not a rotten egg smell. He could not find anything wrong and left. I still have the problem. Any ideas? Only happens when the furnace is running. Thanks!

plumber Tom

11:56AM | 02/07/04
Member Since: 05/10/03
801 lifetime posts
Check the all the returns for a chemical or possibly one of those plug-in air fresheners near the return openings. Just suggesting barb. It's hard to give an accurate answer over the web without actually seeing your unit.

toolcen2

03:58PM | 02/07/04
Member Since: 09/10/03
67 lifetime posts
I would suggest that you check the heat chamber very closely, there may be a hairline crack, and this could be carbon monoxixe gas fumes. also, check for clogged vent pipes,or disconnected vent pipe letting furnace fumes directly into home.

reneeh

04:28PM | 01/14/07
Member Since: 01/13/07
1 lifetime posts
My furnace is natural gas. The smell is not rotton eggs, it's more sweet/yeasty, (some days stronger than others), and happens only while the furnace runs. I've had my vents cleaned, my furnace serviced, tests for CO... I can't get rid of it. Help. What is it, how do I get rid of it, and is it harmful. I've had symptoms.

jen987

09:36AM | 01/16/07
Member Since: 01/15/07
1 lifetime posts
has anyone figured out the problem with the smell?

I have the same problem, and I would like to get some ideas about what could be wrong.

thank you

rjjones

08:16AM | 05/20/07
Member Since: 05/19/07
1 lifetime posts
Four year old manufactured home was purchased in Michigan last fall, winterized with furnace left on at 50 degrees.

There is a smell that comes and goes with using gas stove and/or furnace, or simply having the house closed for afew days. Not a gas smell, it is sicky yeast odor as someone said. Affecting family members differently. I feel it in my nose and throat, hubby smells it and gets a headache, son gets queazy from it.

We have been airing out the house thinking it may be formaldehyde residue buildup from being closed all winter. Could this be? How long would it take to air a house out?

We have had furnace cleaned and checked, the gas company found no gas leaks, mold testing came up negative, tore out like new carpet, CO battery changed with no detection, nothing found to give us a clue, etc.

Are these issues mainly with manufactured homes?

NO problems with water or previous water damage.

We have looked into cleaning vents, but didn't have it done since it could mean tearing the underside of the manufactured home all apart.

Has anyone found any information or solutions?

Please help? Thank you!

jj

fugazi48

08:09AM | 05/21/07
Member Since: 03/08/06
192 lifetime posts
our A/C smells like old man pee due to condensation in the flexible ducts. Menards has a rebate on insulation, so we are going to blanket all the ducts in the unconditioned attic and hopefully not get any more condensation next winter. (condensation is from household moisture seeping into ducts in winter)

BV002949

12:13AM | 01/06/14
im having the same problem it kind of smells like a old heater that's heating up and burning thedust off but it just keeps getting stronger. my farther is a hvac tec and he looked at the furnace and couldn't find anything wrong he asked me to check to see if I could see if there was any burn residue on anything in the furnace where the components areand there was nothing but while I was looking at it I smelled a buring rubber smell and came and went as we turned the furnace on and off to see if we could find aproblem. still haven't found the problem yet I will keep every one posted if we do discover the problem.

BV003768

08:46AM | 04/02/14
I have the same problem. My old furnace was moved a few inches, and a new filter installed. My new furnace has the same filter, so that can't be it.
The smell is silicon-like. I have a feeling they filled in some openings with cheap silicon and when the heater is on, that stuff starts to gas off. I have been running my heater on high with all windows open hoping the smell will "gas off". No success so far. I'll have yet another company come over and check. It's exhausting.

BV003813

09:48AM | 04/06/14
The smell I'm experiencing when the furnace is running is similar to one in a plant where foam is manufactured. Is it possible that the new filter has a different foam than the previous ones? How do we know what to look for in buying a filter so that it, itself, is odorless and free from chemicals? Thank you. Brand names would be helpful.

tammy9803

10:17PM | 04/08/14
Member Since: 04/08/14
1 lifetime posts
When my heat is turned on 70 I get a gas smell and it really bothers me a lot. I called the gas company but they did not find anything. Does anyone have this problem and is it dangerous.

BV004699

12:28PM | 06/17/14
Did you ever figure out what the smell was?

BV006136

08:03PM | 10/27/14
I totally understand what the first person was saying about the smell being a sweet/powdery smell. That is how I would describe it. I do not have gas. I just had a new Trane 20i system installed a little over a year ago and this sweet smell only happens periodically and can happen whether it is heat or AC running. They have checked it out and can find nothing and say they have never had complains of this before. But it certainly is a sweet (sickening) smell. I truly wish someone would figure it out as I too am concerned about toxic chemicals. I have no air fresheners/etc. in my house. It has been happening a lot lately and is doing so now that is why I Googled and found this thread.

BV006185

04:23PM | 11/03/14
I read this on another thread. It makes a lot of sense too.
"My first guess is that dust and other crap from your house is getting past the filter, hitting the heat exchange and burning and that's what you're smelling. If it's old/ripped/cheap to begin with/missing replace it with a decent one and see if that makes a difference " That is just what mine smells like.. Dust burning

BV006503

10:40AM | 12/12/14
we also have a peepee smell which started when we started up the humidifier when we swithed the unit to heat when the weather turned cold. So far no luck with stopping it. in the summer we accidentally had the humidifier on with the a/c until we found out and switched it off. This may have caused condensate in the ducts, which dried but is now causing the odor.
Any comments ?

BV006529

11:21PM | 12/14/14
Has anyone found an answer? I have a 6 month old Carrier heat pump and have been smelling this sickening sweet smell. It sometimes smells like wet paint or mildew. We had technicians come over and completely inspect the system. They said nithing was wrong. There is no mold or mildew, and they said it could be sewer fumes backing up into the system, but they weren't sure. I may have to move if this doesn't get resolved. I can't live in a house much longer if the smell doesn't get resolved. It is affecting my health. I have been nauseated, had increasing migraines and headaches, and have been hospitalized with pneumonitis.

BV006532

09:06AM | 12/15/14
I have the same issue with the old furnace in my rental unit. I've never lived anywhere with gas so have no clue if this is normal or what but I have Copd, and when the heater kicks on my nose gets stuffy and I cough a lot. Eventually it goes away however. I'm scared about gas leaks but smell nothing like rotten eggs either...it is almost like someone sprayed perfume on a space heater and it's burning off.

BV006554

04:38PM | 12/18/14
I am happy to see this! We have the same problem. We moved into this house and have the sweet/powdery smell when the heat is on. I've shampooed carpets, steamed the walls and floors, painted, had ducts cleaned, have run through 3 filters... It's still there! It burns your eyes, and it feels like my sinuses are raw. Carbon monoxide detector doesn't pick anything up. Had the furnace cleaned. Thought maybe some heat escaping the ducts was hitting something smelly, so taped up all joints. Help. Feel like I'd have to move to escape it. Any thoughts? No scented products used in this house, though previous resident did scented laundry.


BV007024

08:18PM | 02/18/15
Same issue here we had a 5 ton unit put in a year ago and been smelling this smell for about 4 months now. Comes and goes

BV007098

10:24AM | 02/25/15
has any one discovered the answer to the sweet smell coming from vents when gas furnace is on? I too have changed the filter, had the ducts cleaned and still the smell is there and it is making me sick

BV007111

09:11AM | 02/27/15
Hello,
As for me my sweet smell coming out of the vents was sewer gases.
When the furnace kicks on it sucks in air, that air circulates through the duct work. The furnace guy told me when the sewer air passes over the flames it is changed to a gross sweet smell.
You will have to wash your bedding, curtains ect to get the smell out as it settles on everything.
The pipe was cleaned out and the smell is gone!...... Hope this helps.

BV007182

03:12PM | 03/04/15
I have this smell too and it's driving me crazy! We've tried many of the suggestions listed here to no avail. Going to have the pipe cleaned next, though I am wondering which pipe you were referring to? I don't wantto spend extra time and money cleaning the wrong pipe since we've already explored soma dead ends. Thanks!

BV007201

12:38PM | 03/07/15
I'm having a similar issue too.

Background:
We moved in just a few months back, and are the first owners. Brand new furnace. Builder recommended that we change the filters more often the first year. SO, two days back, we did! Previous filter was the hazy cob-web type with flimsy cardboard. Installed new filters from Home Depot, with reasonable filter rating. Furnace itself seems to work fine, is blowing air as usual, warms up the house.

Issue:
I can't quite put my finger on it, but something has changed about the quality of air. It has sort of an extra must or particles or something to it... not quite 'sweet' as some describe above, but something like that. It causes eye irritation for me, and sometimes at night, I feel like I can't take a nice deep proper breath and have this urge to open a window.

Also:
Furnace is in its own small utility closet in the basement. When I go down there, the closet is full of some fume. No particular odor, (e.g. not the burning smell, nor gas, nor dust), but something... almost sweet? And it too has the same effect, eye irritation. I just noticed there's a cold air return outside the closet door. But, the haze has been there from the start, why would it suddenly start circulating that - was it the filter change?

What is that 'new furnace smell'? Can changing to a brand new well-rated filter suddenly cause this?

Any thoughts appreciated, and I hope some of the above helps others too troubleshoot these strange furnace fumes...

BV007536

04:17PM | 04/13/15
I found the problem to be sewer gas coming from an empty drain trap next to the furnace that is used to drain condensation from the A/C. It dries up during the heating season from lack of use. the sewer gas is drawn through the pipe into the furnace causing all of the various smells, eye and lung irritation others are reporting. I poured 3 pails of water down the pipe and after running the furnace for a while, the smell and other irritants are gone!

BV008121

12:38PM | 06/18/15
I'm so glad to find this thread!!! I recently moved into a new apartment and my bed is next to the closet with the furnace and this smell is killing me - it wakes me up at night! It is almost like rotten strawberries.

My super thinks I'm crazy but it is because it is all over the building too - but is never consistent. So frustrating!

I'm on the second floor of a 4 story walk-up so if anyone figures this out, I would greatly appreciate it.

The bathroom is next to the closet so there is a possibility of sewage clog but not sure that I can sell that to the Super...?

Would love help/ advice on how to resolve.

BV009127

03:18PM | 10/04/15
Me too. Only Two different odors. One yeasty and the other like cherry pop. I took a photo during the night using my iphone at the duct return and there was a red tinted color coming into the room. Other times the odor shows like a fog of white in the room. It is a brand new home as well!

BV009253

01:05PM | 10/18/15
My house smells bad from the furnace. Including the bedding, cloth furniture, and the smelly air is making me sick.

davidjones

05:16AM | 10/20/15
Member Since: 10/20/15
1 lifetime posts
This may be because of some dust in the filter. It may also because of clogged chimney or electrical defect in the furnace. Contact professional on the subject.

jamessamuel

06:19AM | 10/23/15
Member Since: 10/23/15
1 lifetime posts
It is because of dust collected in the duct. You have to get it cleaned by professional electrician, who shall have best knowledge on the subject. Even when the fault is not get corrected, there might be some other problem.

BV009354

04:18AM | 10/29/15
There is more than one smell described here, but the one most often described is without a doubt hydrogen sulfide. It's a component of sewer gas (along with methane, and other nasty stuff). Some sources say it's non-toxic, but it can cause health problems like migraines.

We have had the same problem, and it turned out the the p-trap for a bathtub we don't use had all of its water evaporate. That allowed the gas to collect under our home, which meant the first run of the heater made us sick. All it took to fix it was running the water in that tub.

1. Make sure your toilets have wax rings and the bolts holding them to the floor are tight.

2. Flush your toilets, run the water in your sinks, and run the water in your bathtubs.

3. Flush the gas by pouring bleach down the drain.

That should clear it right up. You may want to run your blower with the windows open early in the heater season to clear out any lingering fumes and air that has been trapped since last year.

BV010966

09:49AM | 03/21/16
FIXED the sour odor smell. After HVAC guy couldn't figure it out I cut open my furnace exhaust where it goes in the wall to the chimney. Sure enough it was clogged. Vacuumed and removed by hand nearly 5 pounds of dirt, dead bird, and other debris. Problem solved, no more smell.
Img 20160301 130752612

BV011070

05:38PM | 03/30/16
I have the same burnt rubber odor when the system runs. I note that the big duct coming up out of the furnace and going through the air conditioning evaporator just above it gets very hot--perhaps 150 degrees. I had the entire system cleaned and checked--nothing found. The tech said it was OK I may have to open the air conditioning section and see if there is something in there that is cooking. Anything like a dead mouse would have dried up by now. Help!

BV011681

07:11PM | 05/21/16
Adding my 2 cents:

We bought our 30 year old home 2 months ago and when investigating our not sickening, but not really that unpleasant, odor coming from the forced air furnace, we found 2 mummified squirrels and 3 more recently decomposed mice. I'm still dry heaving. :(


BV011737

11:58PM | 05/27/16
Very helpful comment stream. Same story as everyone else and I've excluded carbon monoxide, gas, and refrigerant leak for our oddly sweet odor in the air. The hydrogen sulfide points made hit the mark and I checked out some public health department notes on it which may help others (http://www.idph.state.il.us/envhealth/factsheets/hydrogensulfide.htm). Will be calling plumbers right away because it's causing shortness of breath, sore throat, dizziness, and mild headaches. Opening windows and shutting doors to rooms not in use helps in the meantime.

BV011796

03:27PM | 06/02/16
We have had a powdery odor in our home for months. It irritates eyes, noses, mouths, throats and lungs. It first started over a year ago when we did a little bit of painting. First the odor was strong and sharp. Got into everything: furniture, clothes air all over house. Others are having these same problems with latex paint fumes. I will have our chimney, furnace, and plumbing checked, but the smell problem started the day we painted and has been in the house since. Google this phrase without any spaces:edpaintinginteriorgettingridofpaintsmell. Lots of people are having this problem after painting. Thanks for the info.

BV011812

02:18AM | 06/04/16
Two possibilities:

If you have laminate flooring and you're having respiratory issues, nasal problems and burning eyes it could be that the flooring is off-gassing formaldahyde. Consider whether any laminate flooring has been installed recently. The A/C will circulate any odors that are in your home but it may not be the A/C itself that's responsible.

Second point, is that I once had a heater core in a car crack and it spilled out antifreeze. It smells sweet, almost like cookies (sweet/baked odor). This may or may not be a factor in home HVAC but it may warrant further investigation.

BV015690

08:15PM | 02/10/18
I am smelling an odor and it is getting stronger. I get a metalic taste on my lips. The smell is now on my sheets, and clothes.
It seems to happen when there is moisture outside. Aright before and during. Rain and snow. We are having a lot of snow here Now. This is the strongest odor. And the furnace is constantly running the fan goes off the sound comes on then the fans again. I need help too!

BV015809

11:24PM | 02/27/18
you're screwed.

BV015833

05:16PM | 03/02/18
I also describe it as a sweet smelling yeast smell. Nasty and faint. However, no one else but a lady who cleaned my home can smell it. It is nauseating. I placed mini filters in ceiling vents, replaced furnace filter with a charcoal filter/screen. I have a filter for hallway where heater/ac air blows throw and will replace the old filter. It is so confusing since I have only lived in this home for about 1 year. It is so strong in master bedroom I have not been able to sleep in there. Now the smell seems to be spreading to other parts of home.
I read one of these blogs and maybe there is something nasty stuck in the chimney? So upsetting - I had a person check furnace and another person go in my attic to see if smell originated there. Anyway, my home is for sell now. I'm exhausted climbing up 15 feet to get to my high rise ceiling and replace filters. I'm about done.

BV017531

09:17AM | 09/28/18
Are you running a dehumidifier? It might be a mildew wet smell being drawn up. I had a similar smell in my older basement, and a dehumidifier improved the air quality in my home drastically.

BV018431

04:24AM | 01/16/19
Can anyone give me advice When my furnace is running it smells like A exhaust leak in car but instead it's coming out of my heater ducts?What should I do?

BV018603

12:05PM | 02/05/19
I have a smell coming from my furnace through my vents after it goes off what could it beI'm

BV018633

10:52AM | 02/08/19
It's formaldehyde get yourself a Temtop1000s itis inexpensive and you can check your rooms yourself don't just rely on your HVAC guy.

BV018908

01:33AM | 03/18/19
New furnace for 6 months. Sweet sickening smell in the room near the furnace only.
It’s only when the lower comes on .

Will try the water down the drain thing .
Hoping

BV018908

09:34PM | 03/24/19
Here is solution that worked for me . Elivated the drain pipe from the furnace to the drain . Just a few inches above the drain . With a plastic object.it drains when needed. Does not suck up the sewer gas into the furnace . Drain always had water in it but smells anyway . So no more sweet sick smell with blower

BV019195

07:06PM | 04/30/19
It is an ozone vocs smell you are smelling. I am battling this myself. It's the byproduct of an ozone treatment which has found it's way I to your home. Many people suffer from this and it created major health & respitory issues and if you are sensitized you will smell it more. You may need to check to see if you have been gassed out at some point by a car, hotel, or anywhere who uses those machines. I have no solution on how to remove it as we have tried everything. Trying vinegar into return now. It's nasty & ozone machines should be outlawed.

Homeowner

01:42PM | 05/03/19
Member Since: 05/03/19
3 lifetime posts
I have been having a strange odor now for 2 years. Most prominent when my forced air heater is running. I smell it throughout the house. It smells smoky/sulfury/cinammonlike. It is very hard to characterize. It gets so strong that I smell it with every breath. I get burning eyes and a headache and feel nauseated. My HVAC guy has checked my furnace multiple times and my system is only a few years old. He said nothing is wrong with it. I change the filter with the best type I can get every month. I bought a very expensive air purifier and even that doesn't get rid of the odor. If I don't have the heater running, after a few days the odor usually goes away. It's a closed system, so no real fresh air gets in. I am at my wit's end trying to figure out what it is. My neighbors smoke, but we have a cinder block wall between our townhouses, and it's not really a cigarette smell, nor is it a creosote smell (and my chimney was recently cleaned). I am losing my mind with this awful odor. I've tried tracking temperature/humidity/barometric pressure/wind. It seems to often start in damp conditions but not always. Help!

BV019402

04:23PM | 05/28/19
For what it's worth for anyone on this thread, we've been having a sweet smell recently whenever the furnace runs at my office. We discovered it is an antifreeze leak. When the furnace runs, the antifreeze leaks onto the hot surface of the furnace, then burns off, emitting a sickly sweet smell into the air and into the entire office. I don't know that it is dangerous to smell, but for folks who find this thread, I thought commenting could help. In our case, you can see the antifreeze leaking out of a spot where it looks like a plug came out.

Others have described different smells here, but with the sickly sweet and headache-y smells some mentioned, that sounds like what we've got too. Check for an antifreeze leak in the boiler/furnace! Good luck to all.

BV019484

07:21AM | 06/08/19
I have the same issue, has anyone found a solution? Things I've tried: new ERV system, checking supply and exhaust of furnace, blower isn't near a sewer, blue light, new filters, new furnace, cleaned ducts. I'm beyond sick over this and my kids are as well. Please any feedback would be appreciated.

BV020174

05:43AM | 08/26/19
Go to home depot. Open a box containing exhaust fan duct tubing. Is that your smell? I replaced my bathroom exhaust fan with brand new tubing from home depot. Smells sweet like buckwheat. I live in a windy area and the outside wind blows that duct smell into the house. The next best comparison smell is maple flavored oatmeal

BV020589

01:45AM | 10/14/19
Everything I can find mentions formaldehyde and a possible crack (even a tiny one) in the heat exchange. Which cam be dangerous.


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