DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   HVAC (http://www.diychatroom.com/f17/)
-   -   primary drain on a split ac unit (http://www.diychatroom.com/f17/primary-drain-split-ac-unit-149718/)

Cherry Man 07-09-2012 06:32 PM

primary drain on a split ac unit
 
1 Attachment(s)
Myprimary drain on my split unit does not drain. I cut the 3/4 PVC drain line where it threads into a metal fitting hoping to find a clog. But it was very clean you can see the water dripping inside the unit but it does not pull the water through it. The secondary drip pan is catching and draining the water. Does the unit need to be shimmed like 2 or 3 degrees to get the water to slightly tip in the direction of the drain? Does the vent tube create a suction that pulls the water out?

COLDIRON 07-09-2012 07:13 PM

How old is this unit? You might need a trap to properly drain the water to the primary. Did you blow through the pipe? Sure it's clear?

Cherry Man 07-09-2012 07:43 PM

1 Attachment(s)
Its about 15 yrs old and was reinstalled 6 yrs ago when I remodeled. You can see from the first pic the pipe looks almost new inside. The second pic shows the trap and the vent tube was taller before I cut it down to run a snake down it. I snaked the entire pipe and I poured water down inside the vent tube be4 I cut it down and my wife observed the water draning outside the home. Because there were a couple of 90 degree elbows I could not snake the 12 inches that connected directly to the unit. That's when I determined the clog must be in the threaded PVC fitting but you can see from pic 1 no clog. While the unit runs you can see the water falling from inside the drain pipe but it does not make its way out the primary drain it just overflows primary drain pan and drips down into secondary drain pan If I shim the unit towards the drain will this effect the operation of the AC?

COLDIRON 07-10-2012 06:02 AM

No need to shim after all these years it has to be something inside the coil drain pan causing the problem. Time to take it apart and see why it's coming out the secondary rather than the primary.

biggles 07-10-2012 07:17 AM

that trap is real shallow and if it dries up in the slightest way the pipe will suck/blow air it needs to be deeper so it can hold the last cycle of water during cooling calls.with the unit off pouring water into the condensate pan shoul take the water right out with no overflow.if the fan is sucking air into the connection into the unit the water will stack up and overflow as it is doing then into the emergency pan....there should be 1" from the bottom of the "entering line" to the top of the "leaving line" on that trap.you could build on with some 3/4 elbow andcouplings and short piece of PVC

scottmcd9999 07-10-2012 07:18 AM

Given the age, it's very possible that you have a rusted/rotted/cracked drain pan. If so, then you'll invariably be facing replacement. You can sometimes get a local fab shop to build you a drain pan, but that can take a while, and they can be a real bear to replace sometimes. There are some liquids which supposedly seal the pan, but I've never used them and would consider them nothing more than a bandaid to hod you over until you can get it fixed.

Cherry Man 07-10-2012 08:43 AM

OK Thanks for the info I'm guessing a rotted primary pan. I will shim the ac to drain in the direction of the drain. Create a deeper trap and longer vent tube. Fabricate a secondary drain pan myself. I'll post back an update soon

scottmcd9999 07-10-2012 09:28 AM

There's really no need to create a deeper trap, and in fact doing so can cause troubles. A/C drains produce very small quantities of water, and increasing the depth of the trap can cause drainage issues. The tube that sticks up isn't really a vent tube - it's just a method used by some to make adding chemicals and such a bit easier.

Just keep a very close eye on the secondary pan in the interim. An overflow there can cause significant damange to sheetrock and such.

COLDIRON 07-10-2012 09:43 AM

Quote:

Originally Posted by scottmcd9999 (Post 962249)
There's really no need to create a deeper trap, and in fact doing so can cause troubles. A/C drains produce very small quantities of water, and increasing the depth of the trap can cause drainage issues. The tube that sticks up isn't really a vent tube - it's just a method used by some to make adding chemicals and such a bit easier.

Just keep a very close eye on the secondary pan in the interim. An overflow there can cause significant damange to sheetrock and such.


" I second that"


All times are GMT -5. The time now is 11:02 AM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved