Room temperature reading is clearly wrong (e.g. shows 10°C when room feels warm).

Safety first: No mains work is required.

• Verify with thermometer: Measure room temperature with a reliable thermometer to confirm the discrepancy.
• Relocate thermostat: If installed above a radiator, near a window, or on an external wall, move it to an internal wall away from direct heat/cold and draughts.
• Apply offset: Many Worcester Bosch smart thermostats allow a temperature offset in settings. Adjust by the measured difference.
• If reading is unstable or extreme: The sensor may be failing; replacement of the thermostat is usually required.