strange exhaust fume like odor in home

[redeye1]

Hi, for the last couple of days I have noticed an odor in the house that smells like exhaust fumes when I turn on the air conditioner. I live in the nevada desert and the unit is mounted on the roof of the house and is a combination heating and a/c unit. I had a technician look at it today and he said there is nothing wrong with it and it cools adequetely. I know there must be something wrong because the odor persists when it is running and smells like carbon monoxide exhaust fumes. does anyone have any idea what may be going on here with the unit ? thanks

[Wolfer]

Carbon Monoxide has no odor, BUT natural gas has an odor. Your system turned to cool wouldn't use gas. It could be something else.

Could be a water heater or a leak in a gas pipe.

You should call your gas supplier immediately.

[redeye1]

the a/c section of the unit operates on 220 vac. the odor is more like a car engine exhaust smell but I am perplexed as to how an electric compressor could transfer an odor like that to the blower and into the air ducts.:confused:

[troyorr]

The odor probably isn't from your A/C unit. The odor is coming from your indoor unit. The fan in the indoor unit has to operate, along with other associate electricl components when the outdoor unit is on. How old is your indoor unit? When was the last time it was serviced? Not just looked at but actually cleaned.

[davidr]

Do you have an attached garage on your home?

Is there a gas fired water heater or any other gas appliances located inside the home?

[Shophound]

OP said it was a package unit on the roof. Is the house near a busy highway/freeway? Neighbor next door running a generator, lawn mower, etc.? Smell only intermittent when a/c runs or all the time when a/c runs (night or day, every cycle)? Is there a fresh air intake on the return plenum on the roof? If not, I'd still look to see if leaks have developed in the return ducting, anywhere along its path.

I would also heed the advice about having any possible natural gas leaks eliminated from the equation, and have all gas burning appliances checked for proper combustion and venting.

[marvin]

where are you located have seen this several times on rtu
set ups but never described as co fumes

[Airmechanical]

his drain is probably not trapped

thats most likely the place where the smell/CO gas is entering!

i am not giving DIY advice, i am just trying to extend the OP's life span!



.

[marvin]

have to agree about the trap
also may dropped in to a vent pipe & not trapped.

[redeye1]

thanks for the replies. there is only the outdoor unit on the roof connected to a duct array. Area is rural and no other appliances in home except for refrigerator, washer ,dryer all electric.. I believe now that the odor is more closely related to overheated lube oil of some kind. the odor itself is weak and not pronounced but it is there in every room. the HVAC tech said that he couldn't smell anything but I believe that after 30 minutes in the house you will smell it. Is it possible a bearing is worn and overheating creating the fumes and is being sucked into the blower vortex ? I had the same problem last year with the heating section and the house was filled with fumes.that turned out to be the fan blades that fell off the induction motor and it was natural gas operated but the a/c is electrical only. after living in a house for over 10 years you get to know all the sounds and smells and this smell is something new. :(

[papa_jo]

well you have a gas furance-- did the hvac tech check for gas leaks while he was there??doesn't matter if you have electric a/c unit if it is also a gas furance - smell could be sucked in when blower comes on-- does it smell like a rotten egg??

[redeye1]

Hi and thanks to all for your replies. I left the house for a week and left the A/C on and just returned. the only appliance on was the frig. There was no odor.That's good:). the problem either cleared itself up or the smell must be coming from my big screen tv which is an older one, a projection kind I think. If I start to smell it again I'll know it is the tv since the house smells clean now. thanks all :)

[lost_n_tx35]

Ok, here's what's going on at my house, I swear I smell exhaust in the house but I am smelling it when nothing is running. We live in Big Spring TX and there is an oil refinery here in town and the wind is always blowing, could the smell be coming in through our vents from the refinery? We do have a gas furnace but I am smelling this odor when NOTHING is running, in the summer when the air conditioner is running I smell nothing and once in awhile when the furnace runs I think I smell something for a few minutes then it goes away. My husband and friends say they smell nothing. I have the furnace serviced every year and nobody has ever indicated that we have a leak. But, I also smell this odor when I am outside of my house, at Walmart and another area grocery store. Any ideas ANYONE? I am beginning to think I am imagining this.

[millertime77]

Ok, here's what's going on at my house, I swear I smell exhaust in the house but I am smelling it when nothing is running. We live in Big Spring TX and there is an oil refinery here in town and the wind is always blowing, could the smell be coming in through our vents from the refinery? We do have a gas furnace but I am smelling this odor when NOTHING is running, in the summer when the air conditioner is running I smell nothing and once in awhile when the furnace runs I think I smell something for a few minutes then it goes away. My husband and friends say they smell nothing. I have the furnace serviced every year and nobody has ever indicated that we have a leak. But, I also smell this odor when I am outside of my house, at Walmart and another area grocery store. Any ideas ANYONE? I am beginning to think I am imagining this.
Thats hilarious.

[redeye1]

I resolved my problem with a new draft inducer motor. the cooling fan broke off the old one causing it to overheat and create the fumes.

[lost_n_tx35]

Millertime, Glad to see you think this is funny. I came here because I am nervous about these fumes NOT to be laughed at. If you don't have anything to add other than laughing at me please don't bother to comment. I see you're just learning the trade so before you laugh at people maybe you should become totally qualified!!! Thanks Redeye for your input, I appreciate it!!!

[martin&sonsa/c]

there are alot of smells that can be associated with a packaged unit if its gas it could have a gas leak or it could be a freon leak or even burnt wiring can give of a bad smell but from what your posts have indicated it sounds like the smell from the refinery is the problem but just to make sure i would have a tech come out and make sure he he does check for any leaks i would recoment a a/c check up or heat check up that way he will do a complete check of your system including a combustion analysis and co check. this should put your mind at ease.

[millertime77]

Millertime, Glad to see you think this is funny. I came here because I am nervous about these fumes NOT to be laughed at. If you don't have anything to add other than laughing at me please don't bother to comment. I see you're just learning the trade so before you laugh at people maybe you should become totally qualified!!! Thanks Redeye for your input, I appreciate it!!!

I am very sorry. When I read the thread no one had posted since '08 and ended up being a tv. I honestly thought it was a joke when you started saying you were smelling this at the stores and thought you were imagining it. Your right I am just learning but common sense will tell you that smelling gas isn't good. I hope that you get the problem resolved.

[redeye1]

I am very sorry. When I read the thread no one had posted since '08 and ended up being a tv. I honestly thought it was a joke when you started saying you were smelling this at the stores and thought you were imagining it. Your right I am just learning but common sense will tell you that smelling gas isn't good. I hope that you get the problem resolved.
I started this thread some time ago. the problem has been long since resolved. the draft inducer motor cooling fan broke off the shaft and the motor was overheating creating the fumes. a new motor and fan fixed it. it's amazing the range in price on parts. the motor sold for as low as $*** and as high as ****. I picked it up for the *** including the circular cooling fan that presses on the shaft.

No pricing please.

Mod Team

[lost_n_tx35]

Millertime, apology accepted. It just hit me wrong because like I say it does make me nervous. Yes, common sense says if you smell gas in the home get it checked immediately, but I guess my main question was also if it could be smells from the refinery, where I smell this outside at times and have like I already said at Walmart and the another area grocery store. I am originally from Maine and we heat with NO2 oil there so the gas heat is a totally NEW experience as is the smell from the refinery. I have had neighbors who have lived here all their lives say it's the refinery but also in the same breath they don't really notice it as they have grown accustomed to it. So, I did really want to know as well if I am just imagining this odor where NOBODY else ever seems to notice it. We have only been here 4 yrs now and like I have already said the wind is blowing most all the time here, so I was wondering if the odor from the refinery could be causing the exhaust like fumes that I have been smelling or if I should be more concerned. I have asked my son and others who come to my home if they smell the exhaust like fumes and EVERYONE says NO!! My husband included. I know that sometimes with natural gas that there may be a rotten egg smell, I am assuming it's a sulfur smell of some sort? This however is NOT the odor. I smell it sometimes when nothing in the house is even turned on i.e., the furnace, air conditioner or any other appliance. I have an electric stove so YES I did ask if it could be my imagination. lol I am sorry I got so defensive with you!!!

THANKS to EVERYONE who has replied!!

[millertime77]

If you did have a leak somewhere it would not matter if the equipment was running or not, you could still be smelling gas, because it could be a leak somewhere before the equipment. You should go ahead and have a certified tech do a preventative maintinence on your system, like martin and son says.

[SuzyQisMe]

Every year when I turn my AC unit on, I smell something that smells like gasoline or exhaust fumes. I do not smell it in a friends or my inlaws homes. My indoor ac part is 2-3 years old and is combined with a gas heater. It is not a gas or rotten egg smell. The outside unit is off the back patio. I smell it every spring and summer when I turn on the AC. My husband said he never smelled it and said I'm nuts, maybe so. It happens every year. The smell is driving me crazy. Any suggestions appreciated!!!

[Shophound]

Every year when I turn my AC unit on, I smell something that smells like gasoline or exhaust fumes. I do not smell it in a friends or my inlaws homes. My indoor ac part is 2-3 years old and is combined with a gas heater. It is not a gas or rotten egg smell. The outside unit is off the back patio. I smell it every spring and summer when I turn on the AC. My husband said he never smelled it and said I'm nuts, maybe so. It happens every year. The smell is driving me crazy. Any suggestions appreciated!!!

Is part of your a/c system out in the garage?

[SuzyQisMe]

No I do not have a garage and the car sits in front of the house on the street and the outside unit is quite aways from it. That's why I can't figure it out because it smells just like gas exhaust fumes.

[Dr.phil]

You may want to have your tech check your blower motor, as it probably runs at a differant speed in cooling. You can't do this yourself. Good luck with finding any guy that can smell as well as you can. I know that is one of the things that annoy homeowners when their techs can't seem to smell the same things they can.

[MB101]

I've been having problems with my AC unit with three different leaks and an odor. The leaks have been repaired but the odor has gotten much worse. In fact, it's more like exhaust fumes now. I have Asthma/Allergies and very sensitive to the smell. It has become so bad that it is burning my face, eyes and throat. I have had to turn the unit completely off because it is making me so sick. I can't breathe very well without the AC on and I can't turn it on because of the fumes! Normally I have to run the AC all year long due to the Asthma. The problem is, the techs have checked it several times, cleaned the coils and etc and say that they can't find anything wrong. I live in an apartment complex and have even tried calling a couple of companies to see if they could come out and check it and give me a second opinion but they say that since it is a landlord/tenant situation, they can't. I am completely frustrated and not sure what to do or what it might be. I noticed that a previous poster's situation sounds very similar to mine. (They ended up replacing the draft inducer motor cooling fan that had broken off the shaft and the motor was overheating creating the fumes). I was wondering if this was the same problem that I have, would the AC still work normally (other than the fumes) with a broken off cooling fan? In other words, my AC seems to work fine other than the horrible fumes. Also, is this something that the techs would have easily been able to see when they were checking it or would it require a more in depth look than what they initially did? Any help and suggestions will be greatly appreciated.

[millertime77]

What kind of heating do you have?

[MB101]

millertime77, It is a central heat/air unit that is located in a closet in the bathroom and is located over the water heater. It has BDP co. and Carrier on it.

Thanks