Control indicates 'Circulator Fault', 'Pump Error', or similar; water heater may overheat or fail to deliver hot water.

Safety first: Turn off power. Piping may be hot; use caution.

• Verify call for pump: When there is a demand for hot water, the circulator serving the water heater or indirect tank should run. Listen for motor noise or feel for vibration.
• Check electrical connections: Confirm that the circulator wiring is secure at both the pump and control. Look for burned or loose terminals.
• Bleed air: Air in the loop can prevent circulation. Use purge valves or bleeders near the water heater to remove trapped air until a steady stream of water flows.
• Free a stuck rotor (if safe): Some circulators have a screw plug that allows access to the shaft. With power off and water pressure relieved as needed, remove the plug and gently turn the shaft with a screwdriver to free it.
• Replace if inoperative: If the pump does not run with proper power applied, replace the circulator with a Weil-McLain approved model and gasket set.