Low suction in skimmer


New member
Apr 28, 2017
Crystal Lake/IL
I have 2 skimmers and a main drain. Each has separate plumbing to pool pump. I can isolate each skimmer and main drain. The issue I am having is 1 of the skimmers has low suction. If I close the other skimmer and main drain valves, the suction is now close to normal in that low suction skimmer. If I re-open the valves on the other skimmer and main drain the suction in the skimmer drops again.

Filter pressure is good either way. Stay 25-30 psi. No air bubbles in pump basket or pool. Owned pool for 15 years, and have always had all 3 valves full open and worked great.

any suggestions?

35000 gallons...Sand filter,,,Hayward 1HP pump.. 2 skimmers, main drain each has its own valve.
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Bronze Supporter
TFP Guide
Jul 24, 2015
Central Valley CA
welcome to the forum :handwave:

Does the skimmer that has the low flow have a diverter plate or float valve in it if so perhaps the cam inside is slightly closed or clogged. How are you determining low flow? If the water level is significantly higher than normal it can reduce skimming and make it appear as if the flow is lower than normal. How does the weir look? If they get cracked they can become waterlogged and ride lower in the water reducing skimming and again making it appear as if the flow is lower than normal.


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

Is this the skimmer that you use to vacuum? If so, it could have a pair of underwear as we just saw in another post... :p

Or maybe leaves. If this skimmer has its own Jandy valve, then I would pull the valve apart and see what you can see. If nothing you could try running a wire tape (snake) from both directions.

Jim R.