Question on Smell

[Jack Benny]

We are having a smell come through some of our ducts that kind of smells like cigarette smoke. We've lived in the house for three years and have never had any issues. We did have the air conditioner replaced this summer, but no smells until we turned the furnace on. I did accidentally drop some allergy medicine pills down one of the vents earlier this year.

I've tried to locate any place external to the ducts that the smell could be coming from but haven't been able to find any. Also, it only really comes through on one side of the house. I also had our furnace company out to see if anything was wrong, but they couldn't find anything. I do have a ductwork cleaning scheduled, but am curious to know if there are any thoughts on what it might be. Thanks.

[absoair]

Do you have teenagers living in the house?

Maybe a relative that visits?

Is the return close to the kitchen?

[Jack Benny]

No to all 3 questions. It's not cigarette smoke, but that's the best way I can describe it.

[HVAC_James]

Do you have ac or a heat pump maybe the coil is dirty and needs a cleaning

[absoair]

I am assuming this is a gas furnace? This unit was probably not fired at install. I am guessing this is the heat exchanger getting acclamated to the high temps from the burners. It should go away fairly soon.

Could just be dust on the exchanger or elements if electric.

[Jack Benny]

We have AC and it's new (installed in June). I think the duct cleaning company will clean the coils if necessary. I'm mostly just hoping that having them come out will fix the problem. Since I can't locate any smells external to the ducts, I'm hopeful that it will.

[absoair]

Is this happening in the heat mode?

Is the furnace new also?

[Jack Benny]

The furnace is not new and the smell only started when we starting using the heat. It's actually most noticeable right after the furnace stops but the hot air is still rising through the ducts.

[absoair]

I would call the service company and make sure they ran the system thru a full cycle on and cycle off to make sure of proper fan operation.

[DanW13]

Could be the indoor coil, might have some type of coating on it that might be a irritant to you but not others.

[tuan]

Are you not able to open the vent to see if those allergy pills were burnt to ashes? Most pills including the OTC allery pills don't have any smell to them unless they're burnt.

[LARRIEMENDOZA]

I am assuming this is a gas furnace? This unit was probably not fired at install. I am guessing this is the heat exchanger getting acclamated to the high temps from the burners. It should go away fairly soon.

Could just be dust on the exchanger or elements if electric.

Is it gas furnace or electric elements used as the heater?

[LARRIEMENDOZA]

The furnace is not new and the smell only started when we starting using the heat. It's actually most noticeable right after the furnace stops but the hot air is still rising through the ducts.

I would also say clean /check registers & dampers.

[smooth_operator]

I saw some "creative" A-coil installs where coil was sitting on two pieces of 2x4 wood studs over the gas fired heat exchanger. The wood was right on heat exchanger and was badly burned. I hope that they did better then that, but sometimes techs forget or drop things inside the furnace.

[LARRIEMENDOZA]

I saw some "creative" A-coil installs where coil was sitting on two pieces of 2x4 wood studs over the gas fired heat exchanger. The wood was right on heat exchanger and was badly burned. I hope that they did better then that, but sometimes techs forget or drop things inside the furnace.

Agree...I happen to see that on the field too.Sometimes even we are on a very pressing pressure on service calls,we need to make sure we are not leaving unnecessary items inside units we serviced.