I have an HVAC air handler in the attic above the second floor of my house. It is difficult to get access to the air handler without moving furniture and bringing an extension ladder up to the second floor.

The condensate line from the heat pump runs a few feet horizontally and then down to the basement, where it connects to the sewer line with another horizontal run.

Can I relocate the condensate trap to the basement? This would make it much easier to empty the trap for the winter and clean it as necessary. Would I violate some (U.S.) building code?

  • If you're going to use some type of condensate line cleaning product, you're going to have to go up top anyway, right? Every fitting in the line can form build-up, not just the trap.
    – JPhi1618
    Jul 28, 2023 at 15:22

1 Answer 1


No and yes (to your two questions, respectively). A trap needs to be in a location where it's not likely to be emptied by flow velocity or scavenging. Water would be dropping at a high rate from that elevation and would probably blow past a trap, clearing it.

Well, yes and probably (again, respectively), if you deliberately employ some means of slowing flow so that the trap remains filled to the weir. I doubt that would be technically legal, though.

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