a/c run with burn smell

research · 06-10-2012, 12:09 PM

Hi. The hvac guy told me he has no idea why the unit would smell. He checked the circuit board? thing and it will run with nothing wrong, but it smells like it is burning around the Carrier unit in the basement. He told me that if the circuit part were bad it would just stop. So now I'm supposed to wait for it to stop and then call him.

Everything is running normally. House is cooling fine. Fans are running fine.
Burning smell is around the inside unit (Carrier Weathermaker Infinity Gas Furnace, 10 years old. A/C unit outside is >20 yrs. old).

Any suggestions on what he should look for? We have sniffed everywhere but can't find the source. Thank you in advance for any suggestions.

**beenthere** · 06-10-2012, 12:29 PM

Besides the board, blower motor, and transformer.

research · 06-10-2012, 01:07 PM

Thank you, Beenthere.

Just thought I might add the notes from the HVAC visit.

The notes from the 125 dollar visit are:
"MXA-Type board - working o.k.
Variable speed motor ran o.k.
A/C system working o.k. Cannot pinpoint smell
Nothing heating up.
A/C ok."

**beenthere** · 06-10-2012, 01:59 PM

Is there almost a sweetness to the burnt smell?

research · 06-10-2012, 02:59 PM

The smell is like burned rubber. I also think it smells like burned dust. But the HVAC guy said there is nothing to clean.

It doesn't spread through the vents. The smell stays in the laundry room, concentrated around the furnace unit. I guess it is a condenser in the summer and a furnace in the winter?

**beenthere** · 06-10-2012, 03:40 PM

Its an air handler in the summer. The coil on it is an evaporator coil.