Why does ac drain pan keep filling up with water and not draining?

Question

Our AC handler and drain pan is in the attic. It keeps filling up with water. I drain it, put in some clorox, it stayed dry for a while, then it started up again after a week or so. I finally put down a whole bunch of clorox and what looked like hard water deposits came out. It stayed dry for a while but then it wasn't cooling well. I called a repair man, he added some freon, it worked for a while. Now it is full of water again. What gives?

Answer 1

drain is plugged

Answer 2

My ex wife has the exact same problem, and here is what I learned, and solved to some degree. Actually it's too bad the drain pan isn't in the garage...Anyway. First check the drain line if you are able to access it beyond the point of the pan, as it exists in and through the house somewhere. At some point in the line,,,usually right at or right before that pan there is a sort of P trap. The trap aids in noise reduction,,,"Gurgling sounds"

Also at that spot should be a threaded cap, where you might have added bleach. In my ex's pan is a trip switch that shuts off the AC when/if the water level is high enough,,,BUT if the unit drains properly that drain pan should remain dry,,,especially in an attic. Certainly there will be days of higher humidity which might cause some moisture to collect.

The major issue however, which may be the case,,, in your case, is that somewhere in that drain line, the pipe is too level, or even is higher at some point,(an elbow or connector) than where it is supposed to bypass the drain tubing that empties water into the pan. If that's the case what will happen may be hard water deposits, but in my case it becomes a slimy buildup which causes a backup.

Without knowing the tightness of your house, it's insulation, the age of the AC unit, I can't advise more than first check every foot of that drain line you have access to.

No offense to the "repair man" but he should have checked that first as well. I can't judge his ability or knowledge, but it's possible you didn't need Freon, and if so, then you have other issues beyond the the poor drainage.

My ex's drain line is in the garage, as I said, and the process to cause the water to run downhill was simple. I just found all the points that were working against gravity and altered them.

Rev. Steven

Answer 3

Ac Drain Pan

Answer 4

You may have only partially opened your drain when you poured the extra amount of Clorox down the drain. It stayed dry because the unit was not working properly. When the unit is not working properly it is not causing the humidity to condense on the coils. After the refrigerant was added and it was working properly the water came back.

You may want to run a plumber's snake down the drain to really open it up if you cannot blow it out with compressed air or rinse it out with a garden hose. Plumber's snakes can be found at many hardware or home centers. You will need one that is for the right dimension of the drain tube.

The use of harsh chemicals to try to open the drain can be hazardous and may not work so then you will be in worse shape than when you started.

Answer 5

With the repair man adding freon, Telling me it may have been freezing up due to low charge. Doesn't mean the repair man did anything other than charge you for something you didn't need either. The unit should have 2 drain lines. Ones running on the outside of the house, (That's the overflow) for when the main line gets stopped up. The main line itself will drain back into the house, Usually in one of the tubs, Look at the tubs and on the overflow of the tub, See if it says Drain on it. What I mean by overflow, is the , usually round metal plate that sits high on the tub, below the faucet. This can be removed to check if the drain line is there, Remove plate and use a flashlight, or easy way is to just your finger, i know this is going to sound weird, Insert finger straight in till it hits the back of the pipe, slide finger upward, if u feel an opening, that's where your a/c is supposed to drain. This may be way too much info, Yahoo messenger on this id if you still need help

Answer 6

1. It is more likely to be mold buildup than it is hard water deposits that is why the clorox (or some other bleach) must be used on a regular basis. The more humidity in the air, the more water that goes down the condensation drain.
2. If it is hard water deposit, pour a little vinegar down the drain on a regular basis (NOT AT THE SAME TIME as you pour the bleach down the drain).
3. If your system is low on Freon, the system doesn't work as well and water condenses on the coils and then freezes which causes more moisture to condense on it and freeze. It will eventually plug up the air flow.

Answer 7

You will have to get a bottle of liquid drano to clear the clog. If you are a bit more brave you can get get the more acidic professional strength drain opener. It often goes by the name of "blast out" which is available at plumbing supply stores. It comes in a quart or half-gallon bottle and the bottle itself comes in a thick plastic bag. This mixture is dangerous but it will do the job. All you need is about 2 to 3 tablespoons. Any more and you might burn a hole in the drain pan.

Answer 8

Ac Drip Pan

Answer 9

You have 2 drains attached the drain pan...the main drain and the overflow drain. You should blow both drains out with compressed air and watch your problems go down the drain.
Your drain lines are the white PVC pipe.

Answer 10

my dad had the same problem years ago....his drain line was too small and was getting filled with dust and mixing with the water and clogging the line.....the way we fixed his problem was to take out his drain and the pee trap, and run a straight 3/4 pvc line to the outside boxing.....with a 1/4 fall every ft.......been working now for over 15 years......

if replacing is not something u can do then just take a water hose to attic and stick it to the opening and blast the pipe.....we did this for a few yrs for dad until we got tired of climbing, lol

lic. gen. contractor

Answer 11

Put a mixture of chlorine and water into the drain pan. Not a whole lot of chlorine, just enough to be able to smell it. Approx. 1/4 cup to a gallon would be more than enough. The chlorine kills the algea that is causing the blockages.