I'm wondering if there is a way (and if it's recommended) to allow air into the sump pump discharge pipe once the pump shuts off to eliminate vacuum and help water can flow out quickly.

Right after the pump shuts off and the line is still full of water, I can hear bubbles slowly percolating back through the pipe, the air presumably having to travel 70 feet from the end of the line fighting against water trying to drain out. If there was a valve of some sort to let in air near the high point, I imagine that would break the vacuum effect and gravity/momentum would quickly pull out all the water in the pipe when the pump shuts off. Why do I think that? Well, the pipe had a leak last week which was not good (very bad) in terms of water spraying out, but when the pump turned off I could hear lots of air rushing in as the water evacuated. If there's a one-way valve or something that would let in that air and not let any water out that would be great! The primary purpose of flushing out that water quickly is to prevent it from sitting in the outdoor section of corrugated hose which is prone to freezing.

Details on the set-up: A check valve is connected directly to the pump in the crawlspace floor. From there, a short length of corrugated hose goes up (around some furnace ducts and joists) and connects to 1-1/2" ABS pipe very close to to the crawlspace ceiling. The ABS pipe runs the length of the crawlspace at a slight downward angle, through the exterior wall, then transitions to plastic hose which I drag across the yard during winter/spring to dump the water far from the house.

1 Answer 1


Sure. You can run an actual conventional vent line as for other drain plumbing, or you can use an Air Admittance Valve (AAV, mechanical vent, and Studor® is a brand name often conflated with the generic product type) as for other drain plumbing. Note that AAVs live longer if you locate them as far above the drain line as possible, and note that they don't live forever, so they should be installed in a way that changing them is trivially easy.

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