Suction issues - pipe not priming properly.


New member
Sep 24, 2019
Cape Town
Firstly, I live in South Africa which means that I'm busy reopening my pool instead of closing it :)
I bought a house with a pretty old swimming pool 4 years ago, and I've been having endless issues with suction. Most of the time it was usable, pool cleaner (Zodiac MX6) would move around and clean the pool, just not climb walls.
Basically the water level inside the pump is low, and there is turbulence inside the pump. I also notice bubbles inside of the pool.
Two years ago I replaced my pool pump, since the old one was noizy and was giving me issues. Problem remained.
I convinced myself that the issues was somewhere with the underground piping, since everything was black HDPE (poly) instead of PVC so I assumed there might be a leak at some of the fittings or the pipe might be sucked closed.
So i lost my patience and finally replaced both suction and return pipes with 50mm PVC, but that still didn't fix it.
Running out of ideas a bit - I know that there is an issue with my multiport valve as I can hear air coming through the waste pipe when the valve is set to Filter, however that wouldn't explain why the water level in the pump itself is low, right?
Bizarrely, when I set the valve to backwash or rinse the pump primes fine, water fills all the way to the top. I can't see how the valve position or anything that happens after the pump could affect the pump's priming?
Any ideas will be welcomed!


Mod Squad
TFP Expert
Apr 4, 2007
SW Indiana
Welcome to TFP!

Your multiport issue isn’t the problem. Air can’t leak there because it is under water pressure when the pump is running.

What pump do you have?