Room temperature overshoots the setpoint by several degrees before the boiler turns off.

Safety: No electrical work required for basic checks.

• Check location: Ensure the thermostat is mounted on an interior wall, about 1.5 m above the floor, away from radiators, direct sunlight, and draughts.
• Adjust settings: In the installer menu, reduce hysteresis or enable TPI/modulating control, if available, to improve regulation.
• Lower flow temperature: On the boiler, reduce the central heating flow temperature to reduce overshoot.
• Relocate thermostat: If installed in a poor location, have it moved to a representative room.

If overshoot remains excessive, the internal sensor may be out of calibration, and the thermostat may need replacement.