HVAC Condensate Drain
- Thread starter CADru
- Start date
Help Support Plumbing Forums:
No, a condensate drain line CANNOT be hard piped into a sanitary sewer.
It’s called an “air gap” and it’s there by design. In addition to creating an air gap by doing things the way your photo shows, you can also purchase a device to do the same thing which is a little neater and tidier, and has threaded fittings: https://a.co/d/dhK4skx
CADru
Member
Thank you for the "air-gap" reference @Mitchell-DIY-Guy. With this info in my pocket & additional research:
From NACHI
Why Not Direct Connection?:
From NACHI
Why Not Direct Connection?:
- Directly connecting condensate lines to a DWV (drain-waste-vent) pipe is prohibited in some locations.
- The potential danger is that sewer gases may enter the house through the condensate drain line.
- Even with a trap, direct connections can allow sewer gas to enter the air handler, which is unsafe and unhealthy.
https://forum.nachi.org/t/condensate-drains-and-air-gaps-why/191649/16
If you had a fixture close by you could connect it to a dishwasher tee on the house side of the Ptrap.
Check with your inspector. I have to say that or panties get pissed in.
Check with your inspector. I have to say that or panties get pissed in.
I didn't open up your picture and I thought the black hose was the condensate line. So, after Mitchell-DIY-Guy said there was an "air-gap" there, I opened up the picture. You have an "air-break" that is kinda the same. It depends on how far down the vinyl tubing goes down the rubber hose. If it goes pretty far, an inspector could flag it as there is a chance alga could grow and "seal" the annular space between the vinyl tubing and the rubber hose making that essentially a hard piped connection.
And in opening the picture, I see several things that are a little strange looking.
There is a hose connected to a line with check valve in it that connects to the drain ahead of the condensate hose. What is that for? And what is the gate valve hard piped to the drain line for? Where does that line originate? The copper wye fitting the condensate drain line connects to the vertical drain is wrong as is the depth of the P-trap made out of copper fittings. What fixtures are draining down the vertical line?
Can you provide a sketch of you drain and vent lines in this area?
CADru
Member
This all started with me wanting to replace my laundry tub pump, I would like to address entire drainage system in this area. I don't know why that gate valve and vertical pipe is hard piped into the drain, makes no sense to me. House was built in 1954, have no historical data.
My sketch diagrams all fixture drains and vents connected.
I want make some changes to get this up to code and a cleaner layout as I move forward with laundry tub pump replacement.
Thanks
OK, so it looks like your washing machine is also hard piped to the sewer line. That is not per code. It needs to be connected through an air-break standpipe. I think you can fix this relatively easily.
He might have a possibility of sewage backflow so it’s running through a check valve. Can’t be an air break if it’s running through a check valve.
PeterMelazh
New Member
Yes, you can absolutely have a hard pipe connection at the end of a condensate drain line. It's a good way to keep things neat and secure. Just make sure the pipe is properly sloped so the water can flow easily.
It’s not that simple here in America.
In the USA, our codes do not allow that. A P-trap would be required to be in that line to keep sewer gases from getting into the HVAC air handler. But as our A/Cs do not run all year long in most of the states, the seal provided by the P-trap will evaporate and allow sewer gases to pass through it.
Yes, you could a trap primer on it or add mineral oil to it in non-A/C weather, but our codes do not recognize those as acceptable mitigation of a possible dry trap.
