Bosch EasyControl does not turn on heating for certain rooms controlled by Bosch Smart Radiator Thermostats, even when those rooms are cold.

Safety first: Low risk; mainly app configuration and battery replacement.

• 1. Check zone settings: In the app, ensure each room with a Smart Radiator Thermostat is configured to request heat from the boiler, not just regulate locally.
• 2. Verify pairing: Remove and re-add the problematic radiator thermostat to the EasyControl system.
• 3. Observe valve movement: During a heat request, check that the radiator valve pin moves and that the radiator warms when the boiler is running.
• 4. Replace device: If the actuator does not move despite commands, replace the Smart Radiator Thermostat.

Professional help: For complex multi-zone issues, a heating engineer or Bosch support can review the configuration.