Changes In Water Pressure - Air Leaks?

[jlr26]

HELP! Pump pressure starts at 18 psi but after 10 minutes it drops to 8 psi and the pump motor starts making load noises like it is straining. Water returning to pool becomes very low. I've noticed very few bubbles entering the return lines. Should I check the rubber seals on the cover lids over the strainers on the pump; rubber seal on the cartridge filter; or maybe I need to change a seal between the motor and the pump/impeller; or check the air relie valves for leaks? Any help would be appreciated.

[PoolGuyNJ]

Sounds like a dirty filter. You didn't say what equipment you have.

Scott

[Pool Clown]

Yes, check the o ring on the pump lid. Does your equipment have Jandy valves? The o rings can go on those, and cause what you describe.

Sounds like, for what ever reason, the pump is loosing prime after 10min. Is this the first 10 min of run time in the morning? or does it do this throughout the day? If it does this just once, then seems to flounder, and never get prime back, it could be a leak in the suction line. Try setting the valves for spa the night before and see if the pump works normally in the morning circulating the spa. This will rule out the suction line to the pool.

If it catches prime, looses it, then does this over and over during the day, then it could be something as simple as an o ring cracked, out of place, or missing(yes, it does happen). Also, could be water level just low enough to get the pump going, then once water gets flowing, it drains out the skimmer, pump looses prime, and the whole cycle begins again.