Boiler is very noisy, with loud humming or grinding from the circulator area.

Safety first: Turn off power and allow the boiler and piping to cool before touching the pump.

• Step 1 – Bleed air from pump: Some circulators have a bleed screw on the front. With the system off and cool, place a towel under the screw and open it slightly to release trapped air until water flows steadily.
• Step 2 – Check for debris: If the pump has a removable cartridge, isolate the boiler, drain down, and remove the pump head. Inspect the impeller for debris and clean carefully.
• Step 3 – Verify speed setting: On multi-speed pumps, ensure the speed is set according to system design. Excessive speed can cause noise and erosion.
• Step 4 – Replace pump if worn: If the pump shaft has excessive play or the motor is noisy even after bleeding, replace the circulator with a Bradford White-approved model.
• Step 5 – Refill and purge: After any pump work, refill the system and purge air from all zones.

Note: Running a circulator dry or air-locked can quickly damage bearings.