I have plumbed a Sta-Rite 1hp Max Pro pump and a Sta-Rite System 3 500 cartridge filter with an off line CL220 Hayward chlorinator (all recently purchased from you). Everything runs fine except all water drains back in pool when turned off. What I read tells me I need a check valve to fix the problem (none in plumbing). What do you recommend and where should it be installed? Pump and filter about 3 ft above pool and draining seems to be from both filter and pump sides of plumbing.

Question

I have plumbed a Sta-Rite 1hp Max Pro pump and a Sta-Rite System 3 500 cartridge filter with an off line CL220 Hayward chlorinator (all recently purchased from you). Everything runs fine except all water drains back in pool when turned off. What I read tells me I need a check valve to fix the problem (none in plumbing). What do you recommend and where should it be installed? Pump and filter about 3 ft above pool and draining seems to be from both filter and pump  sides of plumbing.

Lennox H. · Accepted Answer

Hi Bob, You can install a check valve on the return side, install a check valve on the suction side can be very tricky. You do have a self priming pump which good for applications like yours. Depending on the feet of head you do not want to add more restriction on the suction side of the pump.

Question Regarding: CMP Check Valve, 2" Inside, 2.5" Outside, 2 Lbs. Spring, Corrosion Resistant - 25830-400-000