Condense drain line clogged

[930dreamer]

This trap is overflowing, should this be sealed? If it was sealed the ac pan would fill and drain out the secondary drain. It's overflowing onto the ceiling/sheetrock.

This is in a horrible place to get at it, I ran about 22ft of snake line already, no idea if the blockage is in the left or right pipe?

 

[The Cobbler]

the pipe leading to the right is(should be) the drain, the pipe to the left is ( should be) the vent for the trap
probably the stoppage is gunge from stagnant water sitting. try a few cups of bleach , or drain cleaner

 

[TRWham]

Should NOT be sealed. There should be an air gap whenever an HVAC drain ties into a building sewer system. The air handler is at lower than atmospheric pressure when the fan is running and, depending on where the coil is, can draw condensate back into the drain pan if the drain line were sealed and the trap full, and/or sewer overflow can be forced into the HVAC system. Neither of these things is desirable.

You need to clear the drain.

 

[930dreamer]

I poured in 3/4 of a gallon of bleach, only time will tell.

 

[TangoFoxTrot]

Might want to put a shop vac in there if you have one, you can get small adapters that can either **** or blow through the line if your vac has that option.

I bought a Gallo gun that uses a CO2 cartridge to block the blockages as I have a long condensate line that occasionally has issues.

 

[930dreamer]

I blew it out with a compressor, if a P- trap always has water in it, how do I know if its cleared?

 

[DHCrocks]

add some of this to the drain pan quarterly. it will help to dissolve and remove the sludge that is blocking the drain line.

https://www.amazon.com/Rectorseal-68115-Hydrex-Tabs-200-Tablet/dp/B008A3UCYS/ref=sr_1_6?ie=UTF8&qid=1529098244&sr=8-6&keywords=ac+tablets

 

[driftpin]

Because if you put a rag over the exit of the pipe, assuming it exits to the atmosphere, you'll collect what looks like a decomposed mouse which comes shooting-out, though if you can you might want to temporarily block the vent side, so the air pressure goes to dislodge the accumulated slime from the trapped algae. It's like a gel-ball or an algae tampon, but it doesn't happen once a month.

Last time I had a plugged drain line, and used the air compressor to clear it, a lizard carcass was embedded in the slime, I guess it got to the trap in the pipe and got caught in the algae, and couldn't back-out.

My friend who is a HVAC master license-holder uses the little tablets which sit in the drain tray and prevent the build-up of algae in the tray and the drain line. You have to replace them as they dissolve. Any big box store or plumbing supply house carries them. Cheap, fast, easy.

 

[930dreamer]

Zero water in the drain pan, the pipe that goes right drops into the clean out in front of the kitchen- outside wall. The water is sitting at the top of the P-trap= so no air gap.

Edit:

I stuck the shop vac into the outside wall clean-out( fit perfect), blocked off the sink drains and let it rip, bleach smelling water came out and I went back into the baking hot attic and the P-trap is void of water. No giant blobs of **** came out, I ran a gallon of hot water down the p-trap. Ceiling is water stained so I'll continue to check the drain this weekend. A/C is back on.

Thanks GJ

 

[Jackfre]

Get a Gallo Gun. In a difficult position it is pretty easy to use.

 

[bobbyjean]

any chance to just cap that line and run condensate line out to gutter...?

 

[LS6 Tommy]

Your whole condensate drain is piped wrong. The HVAC unit must have a trap before the gap into the waste vent line, and what you have is an Air Break where an Air Gap is required. That vent line should have a receiver bell on the top with about an inch of clearance between it and the condensate drain from the HVAC unit.

Cut out the existing straight 3/4" PVC with the 90° ell on the end, cut in a new p-trap on the 3/4" PVC drain from the unit and put a 90° over the 1-1/4" PVC. There should be a bigger gap between the 3/4" and 1-1/4" PVC.

Difference between Air Gap and Air Break:



I use these traps a lot. They're easy to monitor and clean:



They also make a version with a safety switch that will shut the cooling off to prevent a flood:



Or you can fab one:





Tommy

 

[930dreamer]

So put the p trap on the 3/4" line, and install a bell end into the 1-1/2" line with that p trap removed?

 

[bonneyman]

Your whole condensate drain is piped wrong. The HVAC unit must have a trap before the gap into the waste vent line, and what you have is an Air Break where an Air Gap is required. That vent line should have a receiver bell on the top with about an inch of clearance between it and the condensate drain from the HVAC unit.

Cut out the existing straight 3/4" PVC with the 90° ell on the end, cut in a new p-trap on the 3/4" PVC drain from the unit and put a 90° over the 1-1/4" PVC. There should be a bigger gap between the 3/4" and 1-1/4" PVC.

Difference between Air Gap and Air Break:



I use these traps a lot. They're easy to monitor and clean:



They also make a version with a safety switch that will shut the cooling off to prevent a flood:



Or you can fab one:





Tommy

Another fan of the EZ Trap!

I used a pine ammonia cleaner that I found at an estate sale once. Stuff was great at keeping clean drains cleared. (Wouldn't unclog plugged drains, though). When it ran out, I made my own brew:
3 parts Pine-Sol and 1 part industrial strength ammonia.

To unclog drains: Drain Dawg
https://www.diversitech.com/en-US/item/id/2927

 

[LS6 Tommy]

So put the p trap on the 3/4" line, and install a bell end into the 1-1/2" line with that p trap removed?

Install the p-trap on the 3/4" and the bell end on the 1-1/2", but don't eliminate the trap on the 1-1/2". You'll get sewer gas in the attic.

Tommy

 

[930dreamer]

Super, thank you.

 

[930dreamer]

I added this bell funnel , there's already a P trap on the 3/4" line with a air vent further down.

 

[LS6 Tommy]

I added this bell funnel , there's already a P trap on the 3/4" line with a air vent further down.

Beautimus! It's still technically an Air Break instead of an Air Gap, but it's so much better I wouldn't lose any sleep over it. It's not like your getting it inspected as a new installation.

Tommy

 

[Ohmthis]

I’ve always been leary of putting chlorine type chemicals in the condensate line for fear of them eating the evaporated coil

 

[eddieK]

I’ve always been leary of putting chlorine type chemicals in the condensate line for fear of them eating the evaporated coil

It drains the opposite direction.

 

[eddieK]

your whole condensate drain is piped wrong. The hvac unit must have a trap before the gap into the waste vent line, and what you have is an air break where an air gap is required. That vent line should have a receiver bell on the top with about an inch of clearance between it and the condensate drain from the hvac unit.

Cut out the existing straight 3/4" pvc with the 90° ell on the end, cut in a new p-trap on the 3/4" pvc drain from the unit and put a 90° over the 1-1/4" pvc. There should be a bigger gap between the 3/4" and 1-1/4" pvc.

Difference between air gap and air break:



i use these traps a lot. They're easy to monitor and clean:



they also make a version with a safety switch that will shut the cooling off to prevent a flood:



or you can fab one:





tommy

^^^^^^ this ^^^^^^