# Attic A/C Unit Condensate Trap



## bardad1022 (Jun 5, 2007)

I have two 3 yr old Goodman A/C units in the attic. I came home to a leaking ceiling. When I checked the units the upstairs the drip pan had water. It appears the drip pan is not water tight due to the water coming out of my ceiling. The drip pan drain never had a chance to work since the water was exiting the drip pan. Now to my real question. The drip pan that houses the evaporator has 2 connections one low one high. condensate was coming from the high connection that was capped draining to the drip pan. The low connection is piped to the drain line with a P-trap in it. I cut the PVC trap out and just piped to the drain with no trap using a great slope. This has cured my water problem. The trap was not clogged, I think the original trap sloped back to the evap drip pan, causing the water build up. Finally my question. What is the purpose of the trap on the condensate drain? Will I hurt the longevity of the system? How do I seal my drip pan? Is what I did okay?


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## bigMikeB (May 31, 2007)

The trap is there for the drain to work properly. The secondary pan should be water tight and most experienced contractors put in a float switch to shut the a/c off if the secondary pan is holding water.


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## troubleseeker (Sep 25, 2006)

The trap in this line serves the same purpose as any plumbing trap, to block sewer gases from coming back through the line . If it was a typical big plumbing trap and that is what prevented the pipe from being able to have correct slope, replace it with an ac drain line trap, which simply looks like a short piece of pipe with a shallow u shape bent into it, available at any ac supply, HD or Lowes, and many larger hardware stores. While you have the line apart install a tee or wye very close to the unit, with a short stub up and unglued cap. to serve as a cleanout, and place to pour some bleach into the line occasionaly. Did the pan leak at the fittings, if so seal them with some silicone, or because it is rusting? If the pan is rusting I would try to replace it for peace of mind before it ruins your ceiling again.As with all ac units, it is not a matter of if you are going to get water in the pan(which as stated is an emergency backup measure), but when. If you want to try to waterproof it, get some elastomeric paint from a paint store that deals with waterproofing products, it is applied just like a heavy bodied paint . An emergency shut down switch as suggested by BigMike is a very worthwhile investment, especially for equipment located over finished living space.


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## bigMikeB (May 31, 2007)

*Sewer gas?*

Condensate drains on a/c units don't get tied into the building sewer, they either go outside, to a drywell, or to a sump pump or similar type drain. If they were tied to the sewer and lost the trap seal during the non-cooling months there would be a nice fire hazzard of pulling methane into an electrical environment.


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