Boiler short cycles, turning on and off frequently without long run times.

Safety first: Turn off power before changing internal control settings.

• Step 1 – Check thermostat location: Ensure the thermostat is not near heat sources, drafts, or direct sunlight, which can cause rapid cycling.
• Step 2 – Review control settings: On the boiler control, verify that the temperature differential and outdoor reset (if used) are set according to the Bradford White manual. Increase the differential slightly if allowed to reduce cycling.
• Step 3 – Inspect system flow: Confirm all zone valves and isolation valves are fully open when calling for heat. Clean or replace clogged strainers or dirt separators.
• Step 4 – Check expansion tank and pressure: An improperly charged expansion tank can cause pressure swings and flow issues. Have a technician verify tank precharge and system pressure.
• Step 5 – Professional evaluation: If the boiler is significantly oversized, a hydronic specialist may recommend control strategies (buffer tank, primary/secondary piping) to reduce cycling.

Note: Short cycling reduces efficiency and can shorten component life; it should be corrected rather than ignored.