Help! A/C problems!

[DannyW]

I've outlined before of my experience with A/C issues...limited. I have not yet googled my problem, instead figuring to send a call out to people who have real life advice, versus internet advice.

Cooked dinner tonight and headed upstairs. Immediately I noticed a water leak in the ceiling, right below the air handler in the attic. A steady drip. But the a/c was still producing cool air.

Uh oh.

Pulled down the attic stairs and forged ahead through the 120 degree heat to the attic unit. The drain pan was full and flowing over.

Immediately went to the drain line outside and applied suction with my shop vac. Drain line was not clogged.

So...my initial thought is either the evaporator coil has gone bad or there is a leak in the PVC pipe inside the plenum. The leak seems to be coming from inside the air handler.

Thoughts or advice?

Going to diagnose further in the morning when the attic temp is lowest. Going to be a long night...

 

[Wire Nut]

Sent you a pm. Call that guy

 

[Duff]

I’m no expert but I don’t understand how the drain pan is full if the drain line is not clogged/broke.....

 

[Duff]

I guess I’m asking, is there not a drain line from the pan?

 

[little rascal]

Unlevel.

 

[4HAND]

Mine has a drain direct from handler & 2nd drain from the overflow pan, which acts as a backup if primary drain fails.

I hope this makes sense. I'm not an A/C repairman.

 

[Whitefeather]

Check the drain line to make sure it doesn’t have a sag in it. Makes no sense the pan is full of condensation and not flow out.

 

[georgiadawgs44]

Does the drain line have an open tee close to where it comes out of the coil in the attic? If so the drain line could be stopped up between the tee and the coil. Sucking it out outside would clear the line up to the open tee but not past there.
Also, did you get any water out of the line when you sucked it out? Like are you sure you you cleared it? It could be a stopped up bad and you didn’t get the clog. Normally when I suck one out I get a lot of water and trash out and it comes out pretty fast right after I suck it out.

 

[sleepr71]

Something has plugged the line. Most likely at the drain pan.I have heard of dirt dobbers plugging them from the outside though. I’d run a long piece of wire down the drain line…

 

[sleepr71]

Mine has a drain direct from handler & 2nd drain from the overflow pan, which acts as a backup if primary drain fails.

I hope this makes sense. I'm not an A/C repairman.

This is the newest way..but he should have (at a minimum..a Float Switch on the drain pan that shuts the unit down..if water rises over 1/2 way in the pan. Sounds like no/inop float switch…?‍?

 

[ribber]

Take a long piece of PVC with elbow on it, stick it on outside drain, and blow like heck with your mouth and that should free a clog if you have one. After that, disconnect the drain trap near the inside pan and pour a little bleach in it.

This worked for me a few years ago when my pan was overflowing. I did have some water coming from drain outside but not enough. I have a buddy that does AC work and he told me what to do.

 

[Deerhead]

Some ac units have a water pump to remove the condensation. If the pump is broken the pan will over fill.

 

[Sixes]

It could have froze up due to a clogged filter or low freon and thawed out.

The drain pain should turn off the condensing fans when if the overflow safety switch is working

 

[DannyW]

Thanks for all the suggestions. Thinking through the situation with a clearer mind, and cooler attic, I'm more inclined to believe that I have a clog somewhere rather than a bad coil. In fact I know I have at least one clog.

There are two drains on my unit. Since it's located in the attic, they are both gravity fed drains. One comes out of the plenum, I presume from the coil, and drains to the outside. I have had issues with this one clogging before. When it does, it activates an inline shutoff sensor and kills the power to the outside compressor.

I checked it first. The compressor was running and there was a smaller than normal amount of water dripping from the pipe. I went ahead and sucked the pipe out anyway. Sounded clear and no big gushes came out, just a little trickle. I am going to test it further but for now I think the line from the air handler to the outside is okay.

The second drain is in the pan itself. It's a simple 3/4" PVC draining to the outside. It's self-evident this drain is clogged because the drain pan is overflowing. Due to it's location, only an inch or two between it and the air handler, I'm going to attack it from the outside. We have been having terrible storms all morning, thunder and lightning, so I'm waiting for a break in the action before going out.

But that clog is secondary to the problem - why is my drain pan filling up in the first place?

As someone suggested, I am going to put some suction on the Tee where it comes out of the unit in the attic. I am also going to add bleach to the line, and see if it makes it outside.

Again, thanks for all the suggestions.

 

[DannyW]

BTW...there is no cutoff switch on the drain pan. I checked my other unit and it has a cutoff switch on the drain pan.

Same guy installed both units in 2014. He put a cutoff switch on the drain pan located in the basement on a concrete slab. He DID NOT put a kill switch on the pan in the attic with 3 levels of finished home underneath it.

Sheesh...

 

[Sixes]

The primary drain line is clogged somewhere from algae. The one flowing to the pan should never have water unless the primary drain is blocked. Run some clorox or vinegar down the line. if you don't have a clean out at the unit, then cut the pipe, clean it out with a shop vac and put a clean out in the pipe.

Either way, you really need a float switch to cut off the units when the pan is full, it would save a ton of water damage especially if you was to go on vacation.

 

[Artfuldodger]

OP said his air handler evaporator drain pan has a switch. Does this switch normally go on that pan or the secondary one underneath?

Maybe since the air handler pan has a switch the installer felt like the secondary pan didn't need one.
I'm not sure which pan normally has the switch or if both pans are required to have one.
Obviously the switch needs to be on the secondary pan.

 

[Artfuldodger]

BTW...there is no cutoff switch on the drain pan. I checked my other unit and it has a cutoff switch on the drain pan.

Same guy installed both units in 2014. He put a cutoff switch on the drain pan located in the basement on a concrete slab. He DID NOT put a kill switch on the pan in the attic with 3 levels of finished home underneath it.

Sheesh...

I guess your plan of attack is to unstop the secondary drain pan, find out why your air handler is leaking or sweating, and eventually add a cut off switch to your secondary drain pan?

I have used a water hose to unstop them but it's a bit messy since you have to do it from the outside. Your vacuum method sounds cool.

 

[ilbcnu]

Get you one of these

 

[DannyW]

I guess your plan of attack is to unstop the secondary drain pan, find out why your air handler is leaking or sweating, and eventually add a cut off switch to your secondary drain pan?

I have used a water hose to unstop them but it's a bit messy since you have to do it from the outside. Your vacuum method sounds cool.

Yes, working on that now. There is so much water in the pan that I afraid of getting shocked if I turn the power back on.

I have searched and searched and cannot find the outside drain for the attic drain pan. Well, maybe I have and I'm just in denial. Traced the 3/4" drain pipe from the pan to the eve of the house. Then went outside and the only pipe I can find is...a 1/2" pvc pipe.

Tell me it isn't so...if they necked down that 3/4" drain pipe to 1/2", I think I have found the source of my clog.