Low to Zero Pressure in Filter

[donpolo]

I put a new pressure gauge on as well.

[BigDave]

Could you tell us more about the piping, pump, filter and any other attached gear?

[donpolo]

I have a 48 sq ft pentair FNS plus filter, 1 HP one speed pump (not sure of brand), all PVC pipes. Also I have a Polaris booster pump that drives a Polaris 280.

Thanks

[kelemvor]

Have you inspected the grids to verify they're not damaged? There isn't a valve set to bypass on it, is there?

[donpolo]

kelemvor - I think some of the grids are definitely damaged. I didn't see any tears or holes but the inside manifolds (right term?) on several of them were broken or moved around a little. Needless to say, I've ordered a new set of grids. Stupid question - but exactly how would that affect the filter pressure?

Thanks again for your responses - I appreciate it!

[mas985]

Blocked or damaged grids would probably raise the filter pressure. But when the pump is running can you feel any flow out of the returns? Do you have a check valves on the suction side of the plumbing?

[donpolo]

Yes there is flow from all the returns. And no I do not have any check valves.