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Basement AC coil drain pipe does directly into laundry sink

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We had AC/Furnace replaced recently and it took me a while to notice that there was a drain pipe coming out of AC unit going directly into the leundry sink. The sink clogged up because of the AC discharge. I've read your article on AC installation in the attic and am wondering if the same rules apply to basement installation. I feel like the installers did a lousy job with this - they could have led the pipe into sump pump pit at least, - and I don't see the secondary pipe at all. Can I argue that this is an incorrect installation or can they say that laundry sink is an acceptable "indirect liquid waste receptor" and the fact that it's clogging up is now our problem?

I couldn't find the according Illinois code, but most other regional codes seem to state the following: "No plumbing fixture which is used for domestic or culinary purposes shall be used to receive the discharge of an indirect waste except that in a residence a laundry tray may be used as a receptor for a water conditioning unit." I believe that laundry sink is considered as one "used for domestic purposes".

asked in Cooling System by tipkin (120 points)
edited by tipkin
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1 Answer

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Hi Tipkin,
First thing you should do is check with your local building department on what particular code regulating air conditioning condensate discharge has been adopted in your area, however, the rules listed in my post - http://checkthishouse.com/15/drip-pan-under-the-attic-installed-air-conditioning-coil.html apply to all locations. 
Laundry sink can be used for condensate discharge; the only restriction in case it has an overflow installed is that the condensate drain tubing must terminate at least 2” above its rim / edge. If there’s no overflow hole (I can’t see that on your picture) – 2” above the sink’s edge. So, this particular requirement hasn’t been met and the pipe doesn’t look supported / secured at all, there’s no trap on the line as well.
Your local municipality might require two condensate discharge pipes in some or all locations, they might also permit single pipe with additional protection devices in place, such as safety switches that turn off the system in case of a clogged discharge pipe. Maybe one of those devices has been installed inside the coil compartment (and it’s not visible). 
It might be also difficult to convince anybody that the condensate liquid was responsible for clogging of the laundry sink; it’s just slightly acidic water with dust particles. I’d start from the building department to make sure what’s required in your area and after that verify your installation.
Please let me know if you have more questions, just click “comment” below.
answered by darekrudy (21,730 points)