WiremanWireman · Pool pump won’t run: troubleshooting for electricians · 2023 NEC ·
Pool pump won’t run
Timers and automation, tripped GFCI, capacitor, a jammed impeller and variable-speed drives.
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How it works
A pool pump is usually a single-phase motor, or a variable-speed motor with its own built-in drive. It gets power through a timer or automation system, and current code requires GFCI protection for pool pump motors. Single-speed pumps that hum but don’t turn usually have a failed capacitor or a jammed impeller. Variable-speed pumps have electronics and their own fault indicators, and they often wait for a schedule.
Every question and answer in this guide. Tap “Step by step” to walk through it.
- What does the pump do?
- Nothing, silentIs the breaker or GFCI on, and is the timer or automation calling for the pump?
- GFCI or breaker trippedGround fault in the pump or its wiring
- Timer or schedule was offTimer or schedule
- All on and callingTest: Measure voltage at the pumpExpect: The nameplate voltage (115 V or 230 V), within 10%.
- No voltageTimer, relay or wiring
- Full voltage, single-speed pump silentMotor failure
- Full voltage, variable-speed pump shows a faultVariable-speed pump drive fault
- Hums but doesn’t turnWith power locked out, does the shaft turn by hand?
- Stuck or very stiffJammed impeller or seized bearing
- Turns freelyTest: Test the capacitorExpect: Within the printed tolerance.
- Low, open or bulgingFailed capacitor
- GoodMotor failure
- Trips the GFCI or breakerGround fault in the pump or its wiring
- Nothing, silentIs the breaker or GFCI on, and is the timer or automation calling for the pump?