Boiler frequently short cycles (turns on and off rapidly) during heating

Safety: No immediate safety risk, but short cycling reduces efficiency and component life.

• Check room thermostat location: Ensure it is not near a heat source or in a draught, which can cause rapid on/off cycling.
• Open more radiators: Ensure enough radiators are open to absorb the boiler's minimum output.
• Check bypass: If a bypass valve is fitted, ensure it is not fully closed.
• Engineer tasks:
  • Adjust boiler maximum CH output via settings if supported.
  • Balance radiators to improve heat distribution.
  • Install or adjust an automatic bypass valve if required.

Optimising controls and balancing can significantly improve comfort and efficiency.