Pool pump losing prime

[Esloser]

Every time I start the pump this season, the pump loses prime and has to reprise itself blowing a ton of air through the returns. Last year it would start right up without any air coming out.

Even if I switch from spa to pool, the pump loses prime and I can hear it groaning for a bit before getting started back up.

I’ve also noticed my pool cleaner (pressure side) will just stop mid cycle. The auxiliary pump will still be making noise but not generating and pressure.

Pool is only a few years old. Any ideas? It’s also happening with my deck jet pump. Used to start right up, but now it shoots some water out and then has to rebuild itself.

 

[bmoreswim]

I don’t know if it fits the scenario exactly but a few places to check are the o-ring on the pump basket lid and any drain plugs to the pump or filter. They all have o-rings that can get brittle. Last year my pump had to re-prime each startup and it was the filter drain plug at the bottom with a cracked o-ring.

 

[Esloser]

I don’t know if it fits the scenario exactly but a few places to check are the o-ring on the pump basket lid and any drain plugs to the pump or filter. They all have o-rings that can get brittle. Last year my pump had to re-prime each startup and it was the filter drain plug at the bottom with a cracked o-ring.

Was water leaking out of the drain plug with the cracked o-ring?

 

[mknauss]

With suction side leaks rarely does water leak out. It is much easier for air to be sucked in than water leak out.

 

[Esloser]

With suction side leaks rarely does water leak out. It is much easier for air to be sucked in than water leak out.

Will a leak in the filter discharge also cause this loss of prime? It's weird because the other pump that runs the deck jets exhibits the same behavior.

 

[mknauss]

Loss of prime is associated with suction side issues. Before the pump.

Check your skimmer, weir door, water level, etc.

 

[bmoreswim]

Loss of prime is associated with suction side issues. Before the pump.

Check your skimmer, weir door, water level, etc.

Maybe this isn't the most common reason, but my filter drain plug (cracked o-ring) allowed my filter to fill with air every time the pump was off. This then allowed my pump to have an air "relief" and the water from the pump drained back into the pool. Thus causing it to have lost prime. There is no relief valve between the two on mine. So I believe a leak after the pump can cause a system to lose prime unless I'm misunderstanding what my issue was and what the fix was (this is possible - but it keeps fully primed now).

 

[mknauss]

What you describe can happen. But, your pump should have primed up and operated again. It would just have to do it every cycle. A suction side leak prevents the pump from ever getting primed.

 

[bmoreswim]

What you describe can happen. But, your pump should have primed up and operated again. It would just have to do it every cycle. A suction side leak prevents the pump from ever getting primed.

That’s correct and understood. Thank you.

 

[Esloser]

Ok - so, an update. I’ve been trying to figure this out. I added silicon lubricant to the pump seal. That didn’t resolve the issue. The pump is able to prime itself - just loses prime every time it stops and starts whether switching from pool to spa or spa to pool. The other pump for the deck jets doesn’t prime at all. Just grunts and groans.

Today, I decided to try something and it looks like it may have fixed the one problem. I switched the suction from main drain and skimmers to just skimmers. Now, the main pool pump is functioning correctly and not losing prime with ever start/stop. Does this mean my main drain could be clogged? If the main drain is the issue, could this be why the secondary pump controlling the deck jets is also having the same problem and not priming?

If so, does anyone know a cost-effective way of unclogging the main drain. The pool is 8ft deep and 36,000ngallons. Draining it, refilling it, and replenishing chemicals is probably a $1000 job. Pool company wanted $150 to come out and then $100 per hour for every hour after the first 30 minutes.

 

[mknauss]

If the main drain is the issue, just do not use it. Pools do not need a main drain.

Have you tried the other pump pulling just from skimmers?

 

[Esloser]

Thanks.

The other pump isn’t tied in to the skimmers. I have 4 main drains and I think two are tied into the main pull pump and filter and the other is just used for the deck jets. So, I wouldn’t be able to use the deck jets either with out figuring out how to unclog the main drains.