Thermostat display is completely blank and device does not respond.

Safety: For mains-powered models, isolate power at the breaker before removing the thermostat from its base.

• Check batteries: For battery models, install new batteries, ensuring correct polarity. Inspect contacts for corrosion and clean if necessary.
• Check mains voltage: For wired models, verify that the circuit breaker is on and that there is voltage at the thermostat base (by a qualified person with a multimeter).
• Inspect internal fuse: Some Eurotronic thermostats include a small internal fuse. If accessible and blown, replace with the exact same type and rating.
• Look for damage: Open the housing and inspect for burnt components or a burnt smell near the power input section.
• Replace thermostat: If power is present but the display remains dead, the PCB is likely defective and the thermostat should be replaced.