A/C fan coil catch pan full, float didn't trigger

[bruno]

Hi All,

I went to change the air filter on the A/C and luckily saw the water in the catch pan was about to over flow. Yes, I had neglected changing the filter and it was on its 6th month. My concern is the float trigger didn't go off. One more night of running the AC and it would have been dripping through the ceiling.

At the time I did not think to check to see if the coils had iced over. Even if they did ice over wouldn't the melting have filled the drain with the float trigger?

I put my hand around the open vertical pipe on the main drain and blew. It sounded like something unclogged inside of the unit.

After looking at some videos I learned of the negative pressure with fan units. Could you eagle eyed viewers check to see if my drain pipe was set up correctly to allow the condensation to drain properly? Also, if the water in the p-trap drys our how do I refill it?

Also, any tricks to soaking up the remaining water without making a mess? I've removed most of it with a shop vac, but a little bit remains.

The unit is a Daiken ARUF24B14CA
Picture attached.

Thanks in advance!

 

[Reach4]

How about using a smaller tube to reach the water, and suck on the other end with the shop vac. Make a seal to the big hose with your hand temporarily, or use tape.

 

[Sponsor]

 

[bruno]

Thanks @Reach4 . Of course, should have thought of that.

Any thoughts on the drain pipe setup? Look OK to allow drainage?

 

[bigb56]

There is another pan inside the unit under the evaporator, when that pan fills it should trigger the interlock device and shut the unit down. Perhaps that pan has a hole in it and the condensate is just running out into the overflow pan instead, or the interlock is not set up right, or the path to the interlock is clogged with sludge and the pan is overflowing before the condensate can reach the float and shut the unit down. At any rate the covers need to be removed so the inside pan can be checked/cleaned, I'll bet you have a lot of sludge buildup in the pan and around the interlock device. Sludge is pretty much unavoidable as the dust mixes with the condensate and drips into the pan but it can be reduced by using AC Pan tablets.

Clean the drain by taping up the open vent pipe at the top of the tee and using a shop vac on the other end of the drain pipe wherever that is, probably either outside or at a nearby plumbing vent stack. Use two people and pour hot water into the inside AC unit pan (inside the unit under the evaporator) while the shop vac is running, this will get the line clean. If no helper available just tape the shop vac hose onto the end of the drain and go pour the hot water yourself.

I would also buy a small battery powered water alarm and set it in the overflow pan under the unit. I have a 9 volt one that works amazingly well and the battery lasts for years. I lay it on a small folded towel, if I have an overflow the towel absorbs the water and sounds the alarm. (The towel prevents false alarms from the conductive metal pan, or from any non-related moisture that may form on the pan due to temperature changes.)

 

[bigb56]

Here's the alarm I've been using for a dozen years or more. https://www.amazon.com/Glentronics-Inc-BWD-HWA-00895001498-Basement/dp/B000JOK11K

 

[Fitter30]

Drain line fine with the trap. Switch could be slimed up. Get a couple of wire nuts for 18/ 20 gauge to remove the switch. Switch has a magnet and foam that rides on a piece of round plastic that has a reed switch in it. Post 5 has a good idea with a pan alarm.

 

[bruno]

@bigb56 , thank you so much! I'll pull the unit and clean it up. Great tip with the water sensor.

 

[bruno]

Thanks all! Got it opened up and cleaned out.

On restart there is a slight whistle from one of the panels. I tightened down the screw a little more, but don't want to strip it. The tightening helped, but didn't silence it completely. When I push on that edge of panel the whistle goes away.

The noise is only heard when in the attic. No noise when in the living space. Can I leave it as is. Or should I open it and add some putty seal at the edge of the panel?

Thanks all!

 

[bigb56]

Thanks all! Got it opened up and cleaned out.

On restart there is a slight whistle from one of the panels. I tightened down the screw a little more, but don't want to strip it. The tightening helped, but didn't silence it completely. When I push on that edge of panel the whistle goes away.

The noise is only heard when in the attic. No noise when in the living space. Can I leave it as is. Or should I open it and add some putty seal at the edge of the panel?

Thanks all!

If it bothers you put a piece of foil tape on the panel, or drill in another screw.