Thermostat frequently cycles the boiler or actuators on and off in short intervals (short cycling).

Safety first: Configuration changes are safe, but do not open boiler covers unless qualified.

Steps to diagnose and fix:

• 1. Review cycle settings: In the installer menu, adjust the cycle rate and minimum on/off times to Danfoss-recommended values for your boiler and emitters.
• 2. Select correct system type: Ensure the thermostat is configured for radiator or underfloor heating as appropriate. Underfloor systems typically require slower cycling.
• 3. Check sensor placement: Poorly placed sensors can cause rapid perceived temperature changes. Relocate the thermostat or sensor if necessary.
• 4. Consult boiler installer: If the boiler is significantly oversized, additional measures such as buffer tanks or modulation settings may be required to reduce cycling.

When to call a professional: Persistent short cycling can damage boilers; a heating engineer should evaluate the system.