Low Pressure on Two Zones: Pump or System Issue?

1 HP Goulds Pump, 5 Zones: Two Zones Won't Start in Sequence

Static 45 PSI. Zones need >33 PSI to start. Two zones fail if run after another zone. Head pressure measured at 19-20 PSI (rotors need 35). Pump folks replaced part last year—no help.

Diagnosis: Pump Insufficient

1 HP pump with tank should handle 12-14 GPM easily. But pressure at heads is 20 PSI—pump not delivering required pressure. Tank may also be faulty (check air charge).

Recommendation

1. Verify tank operation – Air charge = cut-in pressure - 2 PSI.
2. Replace pump – 1 HP should suffice if tank works. Get a new Goulds or equivalent.
3. Don't drill yet – Water supply likely OK in N. FL.

Lower-flow nozzles help marginally but don't fix root cause. Fix the pump.