I have a Ducane HVAC system that started leaking out of the evaporator coil housing. Mine looks like the EU1P. I read that i need to clean out the drip pan.

II tried cleaning it by sucking out the buildup with a wet/dry vac and flushing it with bleach solution but it's still leaking out of the back side that I can't get to.

I've heard of people hosing it out, but that seems like it might make a mess and get things wet that maybe shouldn't be. I've also heard of people blowing it with compressed air but i thought that might just blow the stuff around only for it to clog up the system again.

What should i do to get this thing to stop leaking?

  • Your link is broken.
    – Gil
    Commented Jun 8, 2023 at 2:17

3 Answers 3


I had the same issue recently on my HVAC as well.

You probably have a PVC pipe running from the bottom of the evaporator coil housing. The blockage is probably in there somewhere. You can disconnect the PVC and let the condensate drain into a bucket.

If it does drain cleanly into a bucket, your blockage is in that drain line. Either snake it out or replace it. For me, snaking a 3/4 inch PVC with several 90-degree bends was more difficult than buying a couple pieces and replacing the drain line with 45-degree bends that are less prone to becoming blocked.

I filtered the condensate where my new drain discharges into my sump with a paper towel and was shocked how much debris was being flushed out.

  • There is definitely a PVC pipe running from the bottom of the evaporator coil housing, but I'm pretty sure there isn't a blockage in it because when I flushed it out with bleach solution it drained down the pipe to the pump.
    – Howie Ross
    Commented Sep 28, 2010 at 13:45

have you check to make sure the unit is level? if it's tilted the opposite direction of the condensate line, then the pan might fill up back there and eventually overflow and leak.


I realized that I had a similar problem - I completed a few more steps before being happy with the result. While responding to what seemed to be a clogged condensate line but wasn't working, I noticed the screws by the filter on the right side where the drain is were rusted but not the left.

Took the drain line off, nothing was coming from the ac at all. There was a bit of a gurgling sound. Why I do not know, I blocked the drain pipe with my hand and felt suction. When this was done, I realized there had been a bit of the sound of rushing air. When I removed it, dirty dirty condensate came rushing out and stopped immediately still gurgling all the time. I wasn't sure what would be safe to use clean inside drain pan so went with distilled vinegar.

Here's how I added the vinegar to the pan; the drain pipe starts with the elbow then a 3" long piece. This was rotated so the opening is at the top then poured about a half a cup of distilled water and half a cup of white distilled vinegar inside. Gurgling continues.

Waited 2 - 3 minutes then rotated it so it would drain. Lots of gunk came out. Still gurgled, still not draining without blocking the pipe and removing my hand.

I repeated the process but used 2 cups of vinegar and 1 water then waited twice as long to let it drain. There was more debris, bigger pieces too but then the drain was flowing more steadily and clear. (used a clear pitcher so I could see).

The vinegar water was coming out steadily but the gurgling continued. This CAN mean there is air in your freon lines so please continue.

If you had removed the other pipe, put it back on. If that pipe is open, cap it or make sure the top of the over flow is airtight. The air flow and gurgling slowed way down, I went outside and got the piece with the P trap, used an elbow stuck it on the end of the drain.

Huge rush of water came out, air and gurgling sounds disappeared. I will call the ac guy to do a check up, check the freon pressure, etc. as it is almost time anyway.

**if your air handler is in the house, take a minute and look up to where the duct goes up into the ceiling and check that there is a good seal.
my installer neglected to do anything with the 1/8" gap which is like leaving a window open to the attic. hopefully you can wiggle up there and reach it, otherwise you'll have to get it from the attic side.

  • 1
    Freon does not normally make a gurgling sound and if the AC is working properly which it sounds like it is with all the condensate it is just water. If it were freon it would not be working by the time you read this.
    – Gil
    Commented Jun 8, 2023 at 2:17

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