Thermostat cycles the boiler on and off very frequently, causing noise and wear.

Safety first: Control setting changes are low risk; do not open boiler casing unless qualified.

• Adjust cycle rate: In installer settings, reduce the cycle rate or increase the minimum on/off time if available.
• Increase hysteresis: Set a slightly larger temperature differential (e.g. 0.5–1.0°C) to reduce rapid switching.
• Improve placement: Move the thermostat away from direct heat sources so it senses average room temperature.

If short cycling persists despite correct settings and placement, consult a heating professional to check boiler sizing and system design.