No prime after shut off. Experts/Professionals stumped

[chucksings]

When the pool pump is turned off, it will not again prime on its own. Instead, I must manually prime the pump.

This problem began months ago after about an inch of mud was washed into the pool after a huge rain. It took me several weeks to get the mud out. But afterwards, I have been unable to prime the pump except to do so manually.

The pool maintenance company I use have replaced the sand filter (said it had a leak). This did not help. They then installed a 2" check valve. This also did not solve the problem.

Hayward pump with sand filter. Vinyl pool 30,000 gallons with a non-functioning (frozen) booster (Polaris) pump.

What are we missing here?

 

[duraleigh]

Welcome to the forum.

If they put a check valve in front of the intake on the pump, the pump is virtually "forced" to hold prime.

So, what does the water in the pump strainer basket do when the pump is shut off?

 

[Pool Tool]

Please explain how you manually prime the pump?

 

[Texas Splash]

LaGrange? Shouldn't your user name be ZZ Top? I couldn't resist that one. So you must've been caught in all that flooding last year huh? Your reply will help every one guide you to some options that may be available.

Welcome to TFP!

 

[chucksings]

I found a leak on one of the pipes installed with he check valve. They are returning tomorrow to see if this is the cause for the pool not priming.

The water does lower in the pump basket about two inches. It is not emptying.

I manually prime using a little rubber bladder device at the end of a water hose, dropped down into the skimmer. I also plug the outlets with corks until water starts flowing threw. So far it has allowed me to restart the circulation.

I'll report back here when the maintenance people are done with the pipe repair.

Thanks so much

 

[PrivatePilot]

If they put a check valve in front of the intake on the pump, the pump is virtually "forced" to hold prime.

This is what I was going to say. I had prime issues a few years ago because of a significant rise between my skimmer and my equipment and the check valve completely solved the issue. If it's still loosing prime despite the check valve there has to be a plumbing leak somewhere between the pump/check valve/skimmer that's allowing air intrusion.

 

[Pool Tool]

Just a few thoughts. Was the impeller on the pump ever checked? Maybe the mud damaged the impeller and decreased its efficiency just enough to make priming difficult. There are also small ports within the case of the pump which allow it to self-prime, maybe some of these are blocked? With the pump/motor turned off you should be able to feel around the impeller by putting your finger in the hole of the pump strainer basket. You might be able to feel any roughness or asymmetry which could mean damage to the impeller.

I might be an air leak too, but I would think that would force you to lose prime after the pump is running as well.