Pump loses prime?

[xrunnr]

Hi there. Trying to get some troubleshooting done. My local pool company can’t seem to figure this out.
We have a 2 year old in ground pool with a Hayward pump. Every time I vacuum the pool, the pump loses prime. The section where the basket is, before I start to vacuum, it’s primed and full of water. As soon as I start to clean the pool, and set the pump to “CLEAN” mode and I connect the hose to the filter/skimmer box the pump section with the basket is almost 1/3 of water. I can see water flowing in from the pipe, but not enough to fill that section. After about 20 minutes of vacuuming I will see air bubbles coming from the return jets in the pool.

Is this normal or do we have an issue?

 

[Texas Splash]

Welcome to TFP! A few questions back to ensure we understand:
- What make/model pump do you have?
- Does it remain full of prime when not vacuuming?
- You are using a standard 1.5" vacuum hose, connected into the poolside skimmer correct? If so, how old is the hose?
- How far is the equipment pad (pump) from the pool?
- When you say "set to CLEAN", you are referring to the filter correct? What kind of filter do you have?

 

[duraleigh]

Your description is hard to follow so I'll just make this general statement......

Loss of prime more often than not is the result of a suction side leak

This may help Suction Side Air Leaks

 

[xrunnr]

Welcome to TFP! A few questions back to ensure we understand:
- What make/model pump do you have?
- Does it remain full of prime when not vacuuming?
- You are using a standard 1.5" vacuum hose, connected into the poolside skimmer correct? If so, how old is the hose?
- How far is the equipment pad (pump) from the pool?
- When you say "set to CLEAN", you are referring to the filter correct? What kind of filter do you have?

Hi. Make of pump is a Hayward Maxflo VS 500
When not vacuuming, prime is full nd perfect.
2 year old hose, tested with a different hose, no difference. Yes connected to skimmer
Maybe 40 feet
Setting to clean. The pump has. Setting to set the pump to clean mode and boosts the power of the pump to clean better.

 

[xrunnr]

Your description is hard to follow so I'll just make this general statement......

Loss of prime more often than not is the result of a suction side leak

This may help Suction Side Air Leaks

Thanks. We did a pressure test and the lines held pressure.

 

[Texas Splash]

A couple more questions:
- Does the pump pot every go completely dry when vacuuming or just run low?
- Do you use a skimmer vacuum plate, or do you insert the end of the hose down into the skimmer hole?

 

[xrunnr]

A couple more questions:
- Does the pump pot every go completely dry when vacuuming or just run low?
- Do you use a skimmer vacuum plate, or do you insert the end of the hose down into the skimmer hole?

Hi. Pump pot runs very very low, and I can see the water flowing in from the pipe.
I use a skimmer vacuum plate.

 

[frbruno64]

Hi. Pump pot runs very very low, and I can see the water flowing in from the pipe.
I use a skimmer vacuum plate.

If there is more than one skimmer, did you plug those inlet holes to isolate the flow only to the skimmer where you insert the hose?

 

[Texas Splash]

I don't use a skimmer plate because I like to have the hose directly inserted into the suction hole under water. I just feel as though there is less chance of air seepage. But I'll tag @Mdragger88 for some thoughts as well.

 

[Mdragger88]

I don’t love vac plates for the same reason as Tex. Though they do have their place when there is lots of debris as you can leave the skimmer basket in place.

Have you tried just not using “clean mode”?
When you use clean mode before connecting the plate or vac does the skimmer suck air / create a vortex?

I assume clean mode is just a higher rpm- i would try the vac at various rpms.

Also be sure the swivel cuff on the hose is connected to the vac head & that all air is evacuated from the hose

 

[xrunnr]

If there is more than one skimmer, did you plug those inlet holes to isolate the flow only to the skimmer where you insert the hose?

Only 1 skimmer.

 

[Fugacity]

Is this a new problem, or something you've always struggled with?

Is your pump installed above the pool water level?

Are you getting the hose purged of air?

Pool pumps are centrifugal pumps, and if you get air into them, the will stop pulling suction. Once that happens, you have to get the pump head full of water. If your water level doesn't automatically (by gravity) push the air out, through your pipe, into and through your pump, then all of the air in the hose will sit a the high spot (your pump).

Try dragging the hose into the pool by a jet and filling it, then dragging it down to the skimmer.

I find it easier to use the sectioned hoses, and build my hose piece by piece and making sure the air purges each section before I connect to the skimmer port.