Pump Flow Stops During Prime

smh60

New member
Oct 10, 2020
4
Elk Grove, California
The missus told me in the morning she heard strange noises from the pump so turned it off.

This was actually about the pump not being primed and also likely that there was no flow. As for no flow, After doing some checks (listed below), I turned on the pump. Because I had the volute cover off to check the O-ring, the pump pushed out the air and then started what looked like a good priming flow and then the flow just totally stopped. Note pump has max speed of 3450 rpm and I typically use a 2900 rpm priming speed and have never seen trouble.

I can't think of an air leak causing this since there is a very good flow at first that actually goes down to zero after 10-15 seconds.

What am I looking at or searching for?

Checks:
* pool skimmer basket had no debris that would cause a block
* pulled skimmer basket off and a cover to check for any other blockage: none
* pool bottom drain clean (note we have a pressure-run Polaris cleaner working all the time during the pump runs)
* pump volute basket clean
* no backpressure reading on gauge of cartridge filter


15'W-30'L plaster (gunnite?) 3'-6'D 12,000 gal
Pump: Pentair SuperFlo VS 340021
Cartridge Filtered
We pay someone monthly to come out weekly to control the chemistry (even though I am myself a chemist :)), clean baskets, and control the cleaning of the cartridge filters (he says twice a year)
 

cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
4,442
Fletcher, OK
Welcome to TFP :)

Sounds like your pool water level is low and when it tries to prime the pump is sucking in air from the skimmer... please go over to the skimmer when it starts and see what is happening..

Since you found us please take a look around, unless your pool company is coming daily to take care of your pool it is not being taken care of :)

Do you have a salt water generator? if so your probably good but if your not I bet your CYA is out of control...

 
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smh60

New member
Oct 10, 2020
4
Elk Grove, California
Sounds like your pool water level is low and when it tries to prime the pump is sucking in air from the skimmer... please go over to the skimmer when it starts and see what is happening..
One of the things I did in checking was pulling off the skimmer cover and watching the water flow into the skimmer when the pump started. The flow was going in very well to the skimmer return and then just stopped.

But now that I looked at it again, I see the water level was somewhat below a horizontal PVC bar where I like to keep the water level at the midpoint of the bar. We have a shaky water level maintainer so I activated the level again to do the fill.

So I filled it up to the midpoint of the horizontal bar and the prime took at kept. The flow is going well. We will have to be more scrupulous in maintaining the water level.

Thanks for imparting that experience.