Help! - I have a central air unit in one of my apartments but the ...

HOMEOWNER CRIES FOR HELP...

posted: September 8th, 2008 - 2:04pm

QUESTION:
I have a central air unit in one of my apartments but the condensation water doesn't drain out of the 3/4" PVC.I cut into the PVC drain just after the "U" trap and hooked a garden hose up to it and got a great flow of water to the outside where it drains. I also confirmed that water flows freely from the collection pan (at the A-coil) up to the point where I hooked up the hose ...no problem there.The problem seems to be that gravity doesn't pull the water to the drain's exit (outside), but when I hooked up the garden hose, there's no blockage at all!So what could cause water not to drain freely but when hooking up a hose it does flow freely? There's NO place where water travels up hill except where the trap is located (which is before the non-free flowing water).This just started after 2 years of operation. Any thoughts? I don't want to call someone in for this since it's just a simple drain problem (not an A/C problem).

ANSWER: The outlet of your drain trap needs to be one inch lower than the inlet and just because you can blow water through under pressure does not mean that it will drain, the piping may be running uphill at some point also the trap may not be deep enough if the return is too small or a filter is dirty there may be too much negative pressure to drain you may have to increase the depth of the trap.