Not able to prime pump with only Skimmer Valve open

[mstadnik]

I'm trying to start my pump while my sand filter is in Waste mode so I can vacuum out all of the debris and dirt from the pool after a very heavy rain. The pool bottom is covered with dirt and sediment from my yard/mulch overflowing into the pool.

This is only the 2nd time trying to vacuum my pool (brand new pool owner). I read that the best way to vacuum is to isolate all of the suction to one skimmer, which is what I'm trying to do. But the steps I'm taking are preventing the pump from priming. Am I doing something wrong in my steps below??

1. Pump is off
2. Turn sand filter to WASTE mode
3. Fully close the Main Drain valve going into the pump. Skimmer valve is fully only open. I have 2 skimmer baskets.
4. Turn on pump.
5. Pump will not prime. Gets very close and even fully primes for a second or two, but then loses it.

When I've tried to prime the pump with both valves open, it works just fine. But as soon as I try to close the main drain valve after the pump is running, it again loses prime. So I can't prime the pump when the main drain valve is closed and I can't keep a prime when closing the main drain valve after the pump is primed.

I'm stuck.

Any suggestions?

Thank you.

 

[AftonJeeper]

My guess is you are starving the pump. Try starting it up with everything open and close off the main drain partially or to the point you have good suction on the vacuum.

 

[Richard320]

It sounds like your pump is sucking the skimmer dry. Is the water level high enough?

 

[mstadnik]

I'm filling it up with some more water right now. I believe after a few failed attempts in Waste mode, I may lost enough water to inject too much air into the lines. After raising the water level I'll give it another shot; probably with both valves open to start, closing off the main drain a bit after I get it primed. Thanks.