Pump Pressure Declines During Operation: Foot Valve or Water Table

Pressure Starts Good Then Drops: Well System Diagnosis

Recently primed pump. Zones start well but pressure declines within 1-2 minutes. Pressure gauge reads 10-15 PSI, won't recover until shutdown. Recently replaced pressure valve and connections (were taking air).

Two Primary Causes

1. Foot valve failure: Check valve at bottom of well pipe not holding — water drains back, pump loses prime progressively
2. Water table drop: Seasonal decline below well screen intake. Pump cavitates, can't sustain flow

Diagnostic Steps

1. Shut off pump, wait 30 minutes, restart — if pressure recovers temporarily, suggests water table recharge
2. Check well depth vs. static water level — may need to lower pump or deepen well
3. Inspect foot valve — pull well pipe if accessible, or have well service evaluate

Pressure Valve Note

"Pressure valve" replacement suggests a pressure switch or regulator. Ensure it's set correctly (typically 30/50 or 40/60 PSI for irrigation).