Circulator Fault
Weil-McLain
Primary Circulator Pump Failure
Boiler indicates 'Pump Fault', 'Circulator Error', or similar; may overheat or short cycle.
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Seized circulator motor, air-locked pump, failed pump relay on control board, incorrect wiring
How to Fix / Troubleshooting
Safety first: Turn off power and allow piping to cool before touching the circulator.
- 1. Listen and feel: On a call for heat, place a hand on the primary circulator body. It should hum and vibrate slightly. If it is hot and silent, it may be seized.
- 2. Check isolation valves: Ensure valves on either side of the pump are open.
- 3. Bleed air: Use nearby purge valves to remove air from the loop feeding the pump. Air can prevent circulation.
- 4. Electrical check (visual): Confirm the circulator wiring is intact and firmly connected to the boiler control or pump relay.
If the pump does not run despite a call for heat, a technician should test voltage at the pump and replace the circulator or control relay as needed.
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Repair Difficulty
Medium
3/5
Required Part
System Circulator Pump
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