Symptoms
- Hot water takes as long to arrive as it would without a recirculation system
- Pump feels cold or makes no sound when it should be running
- System has a timer or on-demand button that doesn't seem to trigger it
- No unusual noises, just no apparent function
Likely causes
- CommonFailed pump motorThese small pumps wear out over years of continuous or frequent cycling.
- CommonTimer or control settings turned off or misconfiguredSome systems have schedules or modes that can be accidentally changed.
- PossibleTripped breaker or blown fuse for the pump's dedicated circuitA simple loss of power looks identical to a mechanical pump failure at first.
- PossibleAirlock or debris in the pump impellerTrapped air or sediment can prevent the pump from spinning even with power present.
What to do
- Check the breaker or outlet powering the recirculation pump and confirm it has power.
- Review the pump's timer, schedule, or control settings to make sure it hasn't been switched off or set to an unexpected mode.
- Feel the pump housing; if it's cold and silent when it should be actively running, suspect a power or mechanical issue.
- Check for any manual bleed or reset feature on the pump to clear a possible airlock, per the manufacturer's instructions.
- Listen for a humming sound with no movement, which can indicate a seized or jammed impeller.
- If power is confirmed present and settings are correct but the pump still won't run, the pump motor itself has likely failed.
Tools and parts
- Voltage tester
- Manufacturer's manual for the specific pump/timer
Hot water recirculation pumpSearch: “hot water recirculation pump replacement”
When to call a pro
If the pump has power and correct settings but still won't operate, a plumber can replace the pump or diagnose a wiring issue.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.