Boiler repeatedly turns on and off in short cycles without reaching set temperature

Information: Short cycling reduces efficiency and stresses components.

• Check thermostat location: Ensure the room thermostat is not near a heat source or in a draught.
• Adjust boiler temperature: Lower the CH flow temperature slightly to lengthen run times.
• Ensure radiators are open: Keep at least one radiator fully open without a TRV to provide a bypass path.
• Engineer review: An engineer can adjust anti-cycling parameters, check modulation settings, and advise on system modifications (e.g. buffer vessel) if the boiler is significantly oversized.