A/C condensate won't drain properly

Old 02-24-19, 04:43 PM
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A/C condensate won't drain properly

I've had this issue for a year or so. The pan below the air handler filled up because the condensate wouldn't drain. I tried bleach down the pipe with no improvement. I installed some valves and a T near the air handler (see attached photo) so I could blow the line out with water hose - got great flow with the water hose connected - even with it on just a trickle. Re-aligned the valves so the condensate should go down the pipe and outside - I would get the occasional drip but the Air handler would still fill up. I connected a hose to the T to bypass the drain pipe and it flows perfectly down the hose - so I left it draining down the hose and out the front of the garage. After a year, the driveway is moldy and slimy..... so I need to find a way to get it draining the right way again. The line runs over into the wall between the house and garage, down and under the concrete slab and pops up just outside the house in the side yard. Replacing it would be very difficult.

Please let me know if you have any ideas! Thanks
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Old 02-24-19, 05:40 PM
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It's pretty hard to comment without seeing the drain line but it sounds like it's not continuously pitched to outside the house. It must be or the water won't drain.
Old 02-24-19, 07:07 PM
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I don't see the P-Trap. An air handler won't drain properly unless it has a trap on the drain.

Old 02-24-19, 07:11 PM
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That looks like 1/2 inch
pipe and the minimum is 3/4 inch diameter for a condensate drain. The larger pipe is partly to prevent clogs.

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