Leaking AC unit in Attic

[pelletman]

Good evening, I was over a friend's new house tonight and noticed a water stain on one of the ceilings. We went up in the attic and his AC unit was leaking, there is a pan under it but the leak was outside the coverage of the pan. Can anyone tell me what he is looking at here? I have read a bunch of horror stories about people being told they needed entirely new units when all they needed was a capacitor or something (not that that is the problem here) House was built in the 90's and I would guess this is that old. Leaking where the foil is. I am going to try to post video, we will see how that goes. I appreciate any input you may have.

 

[Firebrick43]

The drain is plugged somewhere. While running AC humidity is removed from the air and has to go somewhere. That is usually down that PVC pipe.

The pipe itself could be plugged or the internal pan/port in the air inside the air handler itself. If you take the side off there is an A coil in there with a catch pan underneath it.

Here is a pic I pulled off a google search. White plastic pan with pipes is what needs checked. It will undoubtedly be full of water and overflowing



The pan you see underneath the unit is a secondary pan that really should never have water in it if everything is right.

Doe it have a drain pipe as well?

 

[pelletman]

Hmm, I don't know. I am not with it anymore but thanks for your help!

 

[OccupantRJ]

From my experience I can almost bet that drain setup with the sharp turn is clogged with a snotty goo that develops in AC drains.

 

[PCustoms]

Looks like years of water damage that needs to be repaired.

 

[Notgrownup]

Plugged drain with snot. Needs to be manually unclogged. You can get A/C tabs to put in the pan to prolong the cleanliness of the water but it needs to be cleared in the drain line with a vacuum . Just had mine cleaned but it’s under the house.

 

[Innovate1]

As others have said it looks like the drain for the internal pan is clogged. Pull the plug on the tee near the unit and clean it out. There is likely an access panel so you can see inside to get a better look if that doesn't do it. The pan under the unit should be bigger and extend past the leaking gap. Pans are pretty cheap and pretty easy to swap out. I see it has a drain line. It should also have some sort of alarm so you know when it gets water because it normally shouldn't. When it does you fix the internal pan so you never have an overflow. Instead of an alarm the secondary pan is often routed to an area where you are likely to see the drainage and that's the indication it needs attention.

 

[pelletman]

Thanks for all the input. You guys were correct. He had an HVAC guy in to sort it out and all is good

 

[dcg9381]

That pan is too small for the AC unit and never should have passed inspection.

The "unplug" of the AC drain line will work for now, but I guarantee it will plug again. ACs should be designed to handle this - the pan needs to be properly sized and then needs a 2ndary drain (typically routed over a window where you can see it drip) or a float switch.

I now do secondary drains AND float switches.

 

[chinboys]

Yes, put a water alarm detection device or safety switch onto the pan after clearing the clog and cleaning the evaporator coil.
Change the air filter more often.
And insulate the supply ductwork leaving the air handler too.
You are also getting hot humid air which is condensating on the cold metal of the supply duct which is also dripping away from the metal pan.

 

[fitter30]

Like post 9 pan need to be larger than the whole unit with a float switch to shut unit off if drain stops up. Unit is colder than dew point in attic. Outside unit sweats, units condensate pan starts to sweat soaking the units insulation. Insulation valve goes to zero makes matters worse. Insulating ahu will only rust out the cabinet. Spray foam attic and make it part of the house with vent to living space.

 

[Wrench97]

Yep that pan has either been pushed to the right or it's not big enough for the unit.
Have a look in that vent pipe and see if you see water flowing.