# Home AC Airhandler Drain Clogged Up and ....



## Davexx1 (May 30, 2013)

Our home AC unit airhandler condensation drain clogged up and the water backed up and over flowed into the bottom of the airhandler unit inside the house.  The water soaked the insulation on the floor of the airhandler cavity.  We soaked up all of the water we could and have been running the unit on continuous fan for over 24 hours now, but the insulation there is still damp/wet to the touch.

How is the best way to dry out the insulation?

Is there likely to be a mold or mildew issue there afterwards?

Thanks, Dave


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## Bob Shaw (May 30, 2013)

Not sure about the mold, but you need to get that condensate line cleared-out. I was lucky and I was able to get mine blown-out with an air hose. You should run about a cup of bleach water down the line about once a year. I've heard of people who had to replace their whole condensate line, when they couldn't get it cleared-out. Mine had some red algae in it.

When my house was built, I had my builder, over his objections, put a pan under the a/c and an overflow line in the pan. My wife went out on the deck and said "Is water supposed to be coming out of that pipe out on the deck?" My drain pan saved the ceiling in my kitchen. Every once in a while, I make a good decision. It's rare, but it does happen.


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## Davexx1 (May 31, 2013)

I did get the line cleared with a pump, flushed it out well, poured in bleach, flushed some more, etc.  The clog was some algiae looking stuff.  There may be a low spot in the line where the clog forms.  I need to flush it out more frequently to prevent this from happening.

I am now concerned about the possibilty of mold and mildew forming in the insulation that got wet.  I am guessing it will take a while for all of it to dry out.  Was wondering if there is anything I should do to prevent that now or later.

Dave


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## dwhee87 (May 31, 2013)

If it isn't that much insulation/large of an area, I'd pull the wet stuff out and replace with new. You don't want that moisture laying against the drywall, etc. A roll of insulation is a lot cheaper than a drywall repair job.


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## shakey gizzard (May 31, 2013)

If the unit is in the attic it should dry out quickly!


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## Nugefan (May 31, 2013)

shakey gizzard said:


> If the unit is in the attic it should dry out quickly!



I would think so too ..

or take a box fan up there and let it blow on the area ..


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## Flash (May 31, 2013)

They make some tablets to put in the drain pan of the air handler. I think they are slow disolve bleach based to prevent the alge growth.


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## king killer delete (May 31, 2013)

I take a shop vac and put some sucktion on the drain line just to make sure its not pluged


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## shakey gizzard (Jun 1, 2013)

Mud daubers are notorious for cloggin these lines!


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## Doc_5729 (Jun 1, 2013)

Davexx1 said:


> I did get the line cleared with a pump, flushed it out well, poured in bleach, flushed some more, etc.  The clog was some algiae looking stuff.  There may be a low spot in the line where the clog forms.  I need to flush it out more frequently to prevent this from happening.
> 
> I am now concerned about the possibilty of mold and mildew forming in the insulation that got wet.  I am guessing it will take a while for all of it to dry out.  Was wondering if there is anything I should do to prevent that now or later.
> 
> Dave






dwhee87 said:


> If it isn't that much insulation/large of an area, I'd pull the wet stuff out and replace with new. You don't want that moisture laying against the drywall, etc. A roll of insulation is a lot cheaper than a drywall repair job.



What he said.


I'm assuming this unit is installed in an attic? If so you may want to install a float switch in the overflow pan to prevent this from occurring again.

It's a simple install and wires to the "red" wire on the unit. If the pan fills with water, the switch shuts the unit down.


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## Doc_5729 (Jun 1, 2013)

Bob Shaw said:


> When my house was built, I had my builder, over his objections, put a pan under the a/c and an overflow line in the pan.



If the unit was installed in an attic area OR above a finished area, it was a CODE requirement. The pan should have been installed without requesting it.


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## Davexx1 (Jun 1, 2013)

The AC unit is in the ground floor laundry room next to the kitchen and garage. There is no over flow pan, just a 3/4" PVC drain from the drip pan/tray in the unit routed to the exterior of the home.

When the overflow occurred, I shut the unit off, put a suction pump on the drain pipe outside and cleared the clog quickly.  A bunch of brown algie stuff came out.  The problem was the drain pipe was clogged up some where between the unit and the exterior of the home.  When the drain pipe clogged, the water had backed up into the air handler unit, then over flowed out of the drip pan/tray onto the floor in the insulated air box area.

This unit was installed new in 2008 and does have an overflow cut off valve on it, but apparently it is not working as the AC kept on running and over flowing until I discovered the problem and turned it off.

The insulation in the air box area that got wet/damp appears to be single sheets about 1"-2" thick, cut to fit the sides, bottom, etc. of the air box cavity.  The insulation is still damp down deep but is drying.  I am wondering and concerned there may be mold or mildew in that area.

Dave


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## hobbs27 (Jun 1, 2013)

Dave, it sounds like you have everything under control. Mold likes to grow in cool/damp locations. Once that insulation is completely dry there's no more problems. Mold is bad for very sick people otherwise most of its damage is done in courtrooms with ambulance chasing lawyers. This is what I've been told by engineers in a couple of Quality Air seminars anyways. The hvac guy needs to be aware of mold not because of its potential health problems but for its potential legal problems.


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## Artfuldodger (Jun 1, 2013)

hobbs27 said:


> Dave, it sounds like you have everything under control. Mold likes to grow in cool/damp locations. Once that insulation is completely dry there's no more problems. Mold is bad for very sick people otherwise most of its damage is done in courtrooms with ambulance chasing lawyers. This is what I've been told by engineers in a couple of Quality Air seminars anyways. The hvac guy needs to be aware of mold not because of its potential health problems but for its potential legal problems.



I agree with this answer, more hype that causes hysteria.
There are only a few types of mold that are bad for a few people. 
Just use the tablets in your drain pan as suggested.


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