I just built this house 5 years ago, and every year when we use the heater it stinks in here. It's not the smell of something burning like the first time that you turn it on each year...this is a very weird smell, it makes my whole house stink. We called the AC man that installed the unit the first winter we used it, and he told us that it was a smell coming from the pee-trap in the attic, and it was his workers that made the pee trap in the attic. So my husband got up there and changed it and put a real pee trap up there, they had just pieced together pieces of pipe. But this didnt stop the smell coming in. It only smells when the heat is blowing through the vents. So I have another AC guy coming out this week to see if he can figure out what it is. He had said before when I talked to him that some brand new units just smell the rot when they are turned on. Do any of you know what this could be? I have central air and heat.

Thanks...and I hope someone can help me out!!
Kim

 

I also forgot to say I have a heat pump...not sure if that matters.

Kim

 

Regardless of how the trap is built it will dry out in the winter and can the pull whatever odor is at the exit of the line.

Best is to fill the trap every few weeks in this case.

 

Ok you have a heat pump and the ac coil has a drain line on it with a P trap as it should. Now where does this line drain to in the summer? Sound like to me it runs over to a sewer pipe. "If it does thats not to code". The hot air dries out that trap then the unit can get the methane sewer gas in it. Check this out for sure and lets us know what you find. Dont think a 5 year old unit would have a new ROT smell.

ED

 

I am with Ed on this.. Where does it drain to? Better not be the sewer pipe!

 

There is an odor that starts from the indoor coil that is called dirty sock syndrome.
This is caused by micro organisums that leave waste on the indoor coil and during the defrost cycle the odor seems unbearable. During the defrost cycle the indoor coil gets moist and so does the waste material and then the heat pump goes back into heat mode and heats up the indoor coil and starts to steam off the odor.
I have tried to clean with different chemicals but the one real fix is replacing the return duct and indoor coil.

 

Thanks for the replies, the other AC person I talked to did say that I could replace the coil...is this expensive to do?

Kim

 

Ok I asked my dad and this is what he said:
The drain pipe does go to a sewer vent pipe and the over flow drain pan line goes directly outside of the house.

Is this a normal setup?

Thanks
Kim

 

NO NO NO Just where is CODE there. You cant have this. The methane gas can kill you. The heat dries up the trap and you get vent gas from the sewer

As it should be. Over a door are window,over a sidewalk. its so you can and will see it .if something is wrong with the unit up there .Before it gets to your ceiling.
You can run the main drain line out side also and run it down to the ground with PVC pipe some where.

ED

 

I am with Ed.. Get that drain line moved from the sewer pipe sooon..

Drain it to the side to the outside of the house .