Furnace Condensate Line Clogged

Posted by: JerryBob

Furnace Condensate Line Clogged - 05/15/14 06:20 PM

Does anyone know how and where to unclog a condensate line on a Carrier furnace (circa 2010)? The unit has started creating puddles since I've turned on the AC.

The photo below shows where I think it is, but I am not sure. Does the black corrugated tube on the left that goes into the white housing (the area with all the tags hanging off of them) need to come off and flushed out somehow?

I think the leak is coming from the white PVC drain on the extreme lower right. I made sure that the piece going to the floor drain is not clogged, so I think the clog is somewhere within the unit.

Any advice to save a service call would be greatly appreciated.



Posted by: Corvette Owner

Re: Furnace Condensate Line Clogged - 05/15/14 06:54 PM

Can you use air pressure with a rag (to seal one end) to blow out line? That's how I clear mine.
Posted by: laserred96gt

Re: Furnace Condensate Line Clogged - 05/15/14 07:18 PM

What I see in the pics is your gas line, PVC drain pipe connects to your evaporator coil which is probably on top of you furnace. There should be a service port ( where you can pour vinegar to help keep the drain clean, if they even installed one ) you can try to gently blow it out, or go outside find where the drain comes out and try to vacuum it. Im surprised the float switch hasn't tripped, or if it even has one.
Posted by: bepperb

Re: Furnace Condensate Line Clogged - 05/15/14 07:30 PM

Those black tubes are for condensate from the heat exchanger. Look for something above the furnace itself. Also, I see the pvc pipe. Don't be afraid to remove the panel below the one you've removed (with the little window to view the diagnostic led), though it will have a switch and the furnace won't run with that one removed.
Posted by: JC1

Re: Furnace Condensate Line Clogged - 05/15/14 07:37 PM

Originally Posted By: JerryBob
Does anyone know how and where to unclog a condensate line on a Carrier furnace (circa 2010)? The unit has started creating puddles since I've turned on the AC.

The photo below shows where I think it is, but I am not sure. Does the black corrugated tube on the left that goes into the white housing (the area with all the tags hanging off of them) need to come off and flushed out somehow?

I think the leak is coming from the white PVC drain on the extreme lower right. I made sure that the piece going to the floor drain is not clogged, so I think the clog is somewhere within the unit.

Any advice to save a service call would be greatly appreciated.



Jerrybob,

Your condensate trap is that white box with the two black hoses in it. It gets all gunked up with crud. You'll need to remove the lower door to get it out. There are two tabs that you squeeze on each side and pull the trap up. You can rinse it out with water from a tap or soak it in vinegar for a while.

Here is a link to the part.
http://www.repairclinic.com/PartDetail/Drain-Pan/319830402/2347566

I had a similar furnace. Just replaced it last December due to the heat exchangers rusting out.

Regards, JC.
Posted by: marshall25

Re: Furnace Condensate Line Clogged - 05/15/14 07:37 PM

If it's from the AC, your condensate pan on the coil is probably blocked, then over flowing and draining out through the furnace. Pull the cover off your A-coil and check it out.
Posted by: Chris Meutsch

Re: Furnace Condensate Line Clogged - 05/15/14 08:14 PM

My service tech pours bleach down the drain pipe coming straight from the A-coil every year and tells me to do it every 3 months to keep things clean. I never do, but never had a problem. I second what others have said, it's the coil pan drain.
Posted by: DSparks

Re: Furnace Condensate Line Clogged - 05/15/14 09:16 PM

Pvc fittings at very bottom left of the pic is the drain .....the evaporator sits in a pan and the water runs out of this drain to the outside...basically its plugged up with slime and crud.....2 ways to clean it...quick way is to blow air from outside and should clear it but will probably be temporary but will buy you some time...or take the lower panels and fittings apart and maybe remove coil and pan completely to clean it all real good....just depends how bad it is...
Posted by: ironman_gq

Re: Furnace Condensate Line Clogged - 05/16/14 01:34 PM

Our HVAC tech uses compressed air to blow out the lines and clear the clogs, he then follows up by pouring bleach down the lines to kill the mold and crud that eventually clogs the lines.