Boiler short cycles, frequently turning on and off with little heat delivered

Safety: Short cycling reduces efficiency and can shorten component life but is not usually an immediate safety risk.

User actions:

• Ensure at least a few radiators are fully open to provide adequate load.
• Increase room thermostat setpoint slightly to reduce rapid on/off behaviour.

Engineer actions:

• Adjust the Keston boiler maximum CH output and flow temperature to better match the system.
• Verify that an automatic bypass valve is fitted and correctly set.
• Review control strategy (e.g., weather compensation, room thermostat location) and optimise.
• Consider adding a buffer vessel or additional radiators if the system volume is very small.