AO Smith pool pump runs but filter pressure is very high and flow at returns is weak.

Safety First: Turn OFF power and relieve filter pressure before servicing the filter.

• Backwash or clean filter: For sand or DE filters, perform a full backwash. For cartridge filters, remove and hose off or replace cartridges as needed.
• Open valves: Ensure all return-side valves are fully open and that any water features are not restricting flow excessively.
• Check filter gauge: Compare current pressure to the clean starting pressure. If it is 8–10 psi higher, the filter needs cleaning.
• Verify impeller sizing: Confirm that the impeller installed on the AO Smith motor matches the pump housing model and motor HP. Oversized impellers can overload the system.