Boiler does not start when room thermostat calls for heat, but no fault code is shown

Safety: Turn off power before working on control wiring.

• 1. Check controller display: Ensure the Brötje room controller is in heating mode and not in holiday or frost protection mode.
• 2. Bypass thermostat: At the boiler, temporarily bridge the thermostat terminals (per manual). If the boiler starts, the thermostat or its cable is faulty.
• 3. Inspect wiring: Check for loose or broken wires at both the boiler and thermostat.
• 4. Replace thermostat: If wiring is sound, replace the room thermostat or controller.