Water spot on ceiling


Old 06-23-14, 05:30 PM
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Water spot on ceiling

Today I noticed a water spot on my bedroom ceiling which is on the second floor beneath the Central AC unit that is in the attic. I went up to the attic and looks for and sort of standing water etc. I saw a little drip beneath the PVC pipe coming out of the big metal box. And some stains on the attic floor that had dried but no puddles. The unit is in a big piece of hard plastic that is raised by a platform about 2 inches above the floor.

I've read about sucking the PVC pipe outlet with a shop vac outside to pull out a blockage and I'm going to try that tomorrow. I'm also going to try and seal up the PVC joints to see if that solves the problem.

How do I check the filters around this box....all I see is a big silver box that directs the air to various rooms. (sorry I don't have pics I'm not home right now). Also The plastic tube that the unit sits in (which I assume is to prevent this condensation from leaking) has what looks like a tiny bilge pump in it or sensor to make the unit drain? Should I fill up the pan and see if water sucks out of am I wrong about that?

Thanks in advance, this problem just arose for the first time and i want to stop is before it gets worse!
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Old 06-24-14, 03:06 AM
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Sometimes you can poke a wire into the drain line to unclog it. Your filters are normally placed at the air returns, just behind the grille in the living space.

If the water left a brown stain on your ceiling you'll need to coat the stain with a solvent based primer before touching it up with paint. That will prevent the stain from bleeding thru latex paint.
Old 06-24-14, 11:40 AM
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thanks for the response! I worked on the unit for 3 hours this morning and I think I'm good. I noticed a little water underneath the PVC pipe from the overflow plastic tray and saw that part of the PVC wasn't cemented and the connection was loose. So first I sucked the pipe clean (a bunch of water came out) and ran some bleach through the line and a little leaked out of that exact connection. So I put some PVC cement on the connection and we'll see what happens from there. I looked under the unit it self and there were no leaks and since the pipe area is the only place I saw water I think I got it.

But one last question can I caulk PVC pipe as well just to double-insure its water tight? or is the cement enough?
Old 06-24-14, 11:58 AM
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Properly cemented pipe will be leak free under pressure. You should not have any pressure to worry about. If it makes you feel better, add some caulk, otherwise you should be fine.

Does the "bilge pump or sensor" have any wiring attached? If not, it is a "P" trap and can also be removed and cleaned.
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