Hello,

20 year old Tempstarr gas furnace in attic with AC system compressor attached outside.

I posted a month or so back about a gas furnace not starting due to the inducer motor not running. I played with the fins a bit and got it to start. I have left it alone for a month or so now, but started it up as the colder weather is here. Unfortunately, the motor now is running, but the gas valve was not activating. I noticed that I could hear water in the inducer motor fan assembly. I removed and drained about 4 ounces of water I would guess. I dried it out and re assembled and all is ok now. But I worry, where did that water come from? Did it possibly leak down the exhaust pipe that vents through my attic and out the roof? Could it be coming from the heat exchanger itself? Any ideas? The system has not been in heat mode for any period of time since late in the season last year when it stopped working.

Any help appreciated.

 

I should have added that we did have some sideways rain from the hurricane a few weeks ago also. So theoretically, it could have come down the pipe the way the pipe is installed. Thanks and any other input appreciated.

 

Could be the trap is clogged.

 

As skaggsje suggests, I have seen this when the trap is clogged. They are usually fairly easy to remove for examination and cleaning as they are usually connected to the inducer and the exhaust pipe with rubber couplings and hose clamps. Also make sure the hose connected to the fitting is clear, and remove the cap on the bottom leg to inspect as well.

 

Trap? Anyone have a picture of this for reference? I pulled the inducer fan assembly all the way off and drained and dried. I did not see a trap or drain line on the inducer fan assembly itself. Is that where the trap is or somewhere else that drains down the pvc lines? I always though these lines were only for AC operation for the condensation evacuate.

Thanks for the help.

 

Post the make and model of your furnace from the rating plate in the burner compartment.

You probably have a condesing furnace that has white PVC pipe for vent pipe.

Condensing furnaces have a plumbing system to remove water condensed from the combustion of the gas. The burner compartment has a lower pressure than the atmospheric pressure, so a water trap allows water to drain out of the furnace but maintains that air pressure differential.

The plumbing system of the furnace can get plugged with algae or other debris. You need to check out the plumbing system and be sure all parts of it are clear.

When it's clear, you should be able to remove the inducer assembly and pour water into the furnace and verify that it drains away.