I lose prime when i put skimmer on.in ground pool?

Question

i have an inground pool. with the valve on for both drain and skimmer im fine.but when i restrict it i lose prime.its starts to suck air.plenty of water in skimmer.i put dye in the skimmer with water off and it doesnt get sucked down the drain or anything.i cannot see any leaks nor do i see a large water loss.cant hook the pool cleaner hose because i lose prime right away.

Answer 1

I would say that maybe when you restrict the drain flow, the pressure in the skimmer increases because you probably have a large pump.  You may need to fill the water level to the top of the skimmer before restricting the flow to the drain in order to vacuum, to keep from sucking air.

you could have an obstruction down in the pipes between the skimmer and the filter.

You may need to bleed the valve on your pump/ filter after backwashing it thoroughly.  Your filter is probably full of air especially if it has not been on all winter, or you have been trying to restrict the flow in either the drain or the skimmer, and  have been sucking air.  If you have air pockets in your filter, the pressure will drop, and the skimmer will not suck.  Your filter needs to have ALL air pockets out.

There could be a crack on the connection between the vacuum  to the skimmer.

I also agree with Joe, above, that you could have a leaky valve,(where you are trying to restrict the flow to either the drain or the skimmer) especially if your pool is more than one or two years old.

If air is getting into your pump basket, either you have a crack in the basket itself or the lid, or your rubbler seal is not intact, or most probably, you are sucking the air pockets out of your filter.  There should be a small valve at the very top of your filter, just below all the handles and gauge.  With the filter on, after backwashing the filter thoroughly, open the valve until water starts spraying out of it freely, then close it with the pump and filter running.  This will purge the air out of your filter, and should correct the problem with sucking air into your pump basket.  (make sure your pump basket is full to the top with water and the lid is on before you do this)  Hope this helps.

Answer 2

If youare not sucking air or have a leak it sounds as if you may have a blockage in the line.  Only reason to lose prime is if air is getting in or not enough water.  With pump working on the other side sounds as if a blockage is the only thing left.

Good Luck.

P.S.  There is a remote but better possibility that there is a problem with the valve.  But unlikely