Sand filter air sucking in from waste


May 24, 2018
Martinsville IN
This is my 3rd year owning a pool and I never noticed it before. Everything appears to be working fine but when I turn my pump off o can hear air coming from the waste output. I put my hand over it and confirm air is being sucked in. Maybe a bad seal in the multi port valve? Since it doesn’t appear to be appear to be effecting anything I wasn’t sure if it was worth the time to take that apart. It’s not a lot of suction but if i cover it with my hand I can feel suction start after about 6 seconds. I could put a cap or something over it until I need to use the waste line but wasn’t even sure it was an issue


Well-known member
Jun 30, 2019
New Jersey
Probably the spider gasket. I had the same issue this spring, plus it was dripping water out the waste port. Replaced the gasket and its all good now.


Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
Franklin, NC
I agree, most common is the gasket. Yes, you can put a cap on the waste line until you get it changed, but some air will still get in.

Here is an older thread that may help: