Central AC drain pump fail, flood

[LeakySeals]

Seems like one problem after another with the house HVAC this year. This time it was the central AC condensation pump tube that goes to the drain pump. Which pushes water outside during the cooling season. It clogged with some kind of crud and flooded a finished basement drip by drip for maybe a month. We have booms, water alarms, caulking all around the base of the partition walls of the room the HVAC is located in. But because of the slow drip it penetrated the concrete, got under the boos, caulking, into the floor and out into the room. The basement family room is finished. It does have supposed flood and mold proof pads underneath the carpet but it's definitely wet and has not dried fully in several days. I've done my best with fans and wet vacs.

Now that I found the problem and fixed it I'm looking for opinions on sealing concrete floors. Some say it's good some say don't do it. I would like to seal the HVAC room floor with some type of sealer so water will not absorb into the concrete so easily. There is nothing on the floor in that room it's just naked concrete which is in good shape. Or is there a better solution.

 

[Donald]

There are tablets you can toss in the drain pan of the AC so the crud will not build up. Also a large as possible drain tube is a good idea. Toss a tablet in the condensate pump also.

 

[mattwithcats]

UGL Drylok...

http://www.drylok.com/products/drylok-original-masonry-waterproofer.php

 

[440Magnum]

I feel your pain... I'm currently replacing my THIRD central system of the summer (all in rental properties). The most recent is one I hate to see go... a circa 1990 Lennox Dimension heat pump. The Dimension outdoor units had the best cabinet design of any home system I've ever seen, and were super quiet. Especially for the last 80s and early 90s. The outdoor unit is still fine, it was the evap coil that died, and being an R22 system it doesn't make sense to repair it.

As for your concrete question... I would look at products made for finished concrete floors, which went through a surge in popularity a few years back. I'm sure the modern trend is synthetic polymer finishes of some sort, but back in the 60s my parents had a sunroom with a finished concrete floor. It had just sanded and then coated and polished with a few of layers of tinted Trewax brand carnauba wax, which they reapplied wax every 4-5 years. It was quite waterproof, although standing water would create a whitish spot that would fade over a day or so after you dried it up.

 

[ARCOgraphite]

This happened to in my Mother's 2nd floor condo in FLA. A Closet Updraft Unit.

It overflowed the drip tray and then drained into the updraft air handler ducting then dripped out of that into the neighbors garage below. After trying to get this fixed on the phone with two contractors unsuccessfully (plenty of idiots down there in FLA) . I looked at it when i visited for her Birthday.

The evaporator A-frame was rusting and shedding flakes into the drip pan and this stuff was clogging up the drain - which was but 1/2 PVC. Fixed that clog but, still not draining properly. then I noticed the drain pipe was pitched UP about 2 inches where it was routed around the side of the closet unit. Tied that down with a clamp and all is well.

I would have the drain at 1-1/2 minimum Then you could do something at the exit to keep the lizards from making a home in there.

Found out later the neighbor lady was putting vinegar into the unit to "freshen it"..



Note: Will someone tell women that vinegar is ACID? Does a job on glazing in the toilet too. Takes it right off. Not Good.

 

[WyrTwister]

Also , try a water alarm on the floor ?

 

[Fawteen]

First, you need a drain float switch. That'll prevent HVAC drain backups.
Second, once or twice a month dump a cup or so of bleach into the drain. That keeps it clean.
Third, put a water alarm on the floor near the drain. That will alert you in the event that you forget to do the above.
As far as your concrete floor, I personally would not seal it. Especially now that there's been significant water on top, and with no idea what moisture is coming up through it, you're just asking for a coating failure.

 

[gman2304]

Won't help you now but I hook my shop vac to my condensate drain and suck all the crud out once a year as a PM.

 

[Kestas]

I was taught to PM the condensate drain on my a/c by pouring dilute bleach through it every now and then. I like the shop vac idea.

 

[Dave9]

Try to avoid bleach, even the fumes will wreck havoc on the evaporator aluminum fins, and isn't going to do steel or copper any favors either. I mean it can be done, but just expose the PVC to it and flush it out the pipe.

The tablets are a better approach to slow it down, though you may want to cut an access panel to facilitate that if there's no easy entry. Otherwise, you can shop vac from the other end (blocking the vent tube if present and taking the pump out if too much of a restriction), or do the same with low pressure compressed air if you have the stack open, which you should do (open the stack, not necessarily blowing the compressed air) every now and then to clean the evaporator.

It is easier to put air through it before fully clogged, on a maintenance schedule, than waiting till it is fully clogged.

Sealing the floor, the water still has to go somewhere so you'd need to consider the grade of the floor to place a water sensor, and if your unit doesn't already have a sensor that shuts the AC off, that is another option with added cost and the need to wire it in, if nobody is going to be present, and in a location they can hear a water alarm. Granted for extended periods away from home (several days) you can set the AC to a higher temp or shut it off.

You an also use a manual pump to clear a clog, there are some marketed for the purpose but they're usually more expensive yet about the same as this type of automotive fluid transfer pump:

https://www.amazon.com/gp/product/B0181EDCZ6/

A manual pump can do "some" clogs but is obviously not as powerful as compressed air, handy to have but not going to fix worst cases. On the other hand sometimes all you need is a bottle brush at the drain pan nipple, it commonly clogs there first.

 

[Fitter30]

Water alarm there are several types.
https://www.amazon.com/Detector-Det...&hvtargid=pla-765332681712&psc=1

Coil cleaner dilute to clean slime out of drain and be used spraying on the coil when ac is being used. Cleaner and dirt will flow out with condensate and has a pleasant odor.

 

[vwmaniaman]

I have used a plumbing snake on mine before with a cut up rag on the end. Lots of snot will come out. I didn't use glue on the elbo that hooks up the drain line. Makes it easier to clean that way.

 

[Dave Sherman]

You might go look at the pump, it may have an overflow switch that could be wired to stop the A/C. The condensate pump in my old house had that option.