By: Monte Leeper
Q.
I have a problem with my central air conditioner. Water is dripping through the ceiling and will ruin my carpet. I think it is coming from a pan overflowing in my attic. The air conditioning repairman came, after I called several times, and said he fixed the problem, but now it is back again. Why is this happening and how do I solve it once and for all? I am so frustrated and I read your column on a regular basis and find your insights helpful.
A.
So, your drip pan runneth over and you wonder why. Condensation in the fan unit that circulates cold air into your ductwork can build up in the pan beneath it if the pan is not sloped properly to a drain. Also, the drain pipe may be clogged, so that the pan runs over onto your attic floor or in between the ceiling joists and then down through the closest opening, such as a recessed light fixture or a screw, nail, or tape joint. The pipe must be located, either from inside the attic, outside where the pipe drips to the ground or into a rain gutter, or into a crawlspace. If it drips to a crawlspace under the house, you can have other problems, such as termite swarming, or mildew build-up. The pipe should drain to the exterior, not the interior. After locating the pipe, it must be cleared by one of several methods. I recommend using a wire that electricians employ, known as a "fish tape." It is a stiff, thin metal probe that comes on a reel and is used to move wire through tight areas in walls when putting in electrical wires. Whichever animal you choose, it is referred to as "snaking" or "fishing" the wire. Get an old sock and tie it twice through the loop on the end of the wire, after drawing the wire through the pipe from the other end. Next, wrap the rag or sock a few more times around the wire. Tug and pull on it as hard as you can to be sure it will not come off. When you insert this old sock into the pipe, the last thing you want is for the sock to come loose. If you thought the pipe was clogged before, you will not believe how clogged it will be if the sock or rag comes off in the pipe. Pull it through from the inside to outside, which I prefer, and you should notice the water in the drain pan slowly begin to flow. Check to be sure that the drain pan is sloped from all directions to the pipe. If it is not, drain the pan and either re-hang the pan or prop the pan to create the correct slope. The prop material should be something that is permanently in place, such as a framework of lumber from below, or wires hung from the rafters above. Anything that can be slipped out will probably move and cause water to spill through the ceiling again. A special switch referred to as a "spill switch" or overflow switch can also be installed to shut the unit down before the next spill occurs. This switch should be installed by a professional, unless you are very handy. If installed incorrectly, you will need a professional to do more repair then you planned on. Cleaning the drain and changing the air filter should be done every summer, at least once and more often if you run your air conditioning all the time.
Readers are encouraged to send questions to: HERALD Homes, 379 Central Avenue, Lawrence, N.Y. 11559 Attn: Monte Leeper, Architect.
