lose prime at backwash

[mitymurph]

To add to my previous "air bubbles" post, the pump now loses prime when I move the control valve into the backwash position. There is a feeling that suction is being lost when I move the valve to backwash. I can then prime the pump, backwash, rinse, and move to the filter positon without loss of prime.

Jim

[DanO]

I don't know what kind of filter you have, but perhaps when you switch the valve to "backwash" it is simply sucking air in through the backwash hose.

I have a sand filter, and mine certainly behaves this way. As soon as I switch it to backwash, I immediately start the pump so that I don't lose prime. After backwashing, I turn off the pump and immediately switch it back to "clean". Then I usually have to bleed a little air out of the system.