Problems after multiport valve swap


New member
Jul 6, 2020
Birmingham, AL
Hello everyone,

I own a ~20,000 gallon salt water pool in Birmingham, AL. The age of the pool is unknown, but my above ground PVC is brittle. My Hayward multiport valve was leaking everywhere, and the previous owners left me a brand new one. So, I had my plumber come over and help me swap it out. It was straight forward, and he installed some disconnects into my existing lines. Since then, my pool will bounce between 2-4 PSI but no more. Before the swap I think it held steady around 12 or so. Also, before the swap, I had a couple bubbles coming out of my first return jet. Now, I have air coming from both jets.

Any ideas as to why I cannot build pressure or why the bubbles increased? Both skimmers are empty, and I have replaced the seal on the pump basket.

Last edited:


Mod Squad
TFP Expert
Apr 4, 2007
SW Indiana
Pool Size
Liquid Chlorine
Welcome to TFP!

The multi port valve is under pressure, so problems with it are unlikely to let in air. Air is likely being introduced through the union on the line or lines going to the inlet of the pump.


New member
Jul 6, 2020
Birmingham, AL
Update - had a leak detection company come out to my house. The tested the skimmer, feed lines, and return lines. They found no leaks. They could not test the main drain because of leaves on the bottom (my fault,) so I plugged the line on both ends with stoppers - neither problem was effected. I am still losing several inches of water a night, and I have bubbles in my return line. I am at a loss - I really thought the leak detection would give me an answer.
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