Worked great for several years. Suddenly stopped. Replaced batteries, cleaned contacts. No sign of life. Is there a way to bypass the thermostat and fire up the boiler until we can get a new one? Thanks in advance.
I guess the relay could have failed in an open state. Do you hear it clicking when you increase or decrease the temperature?
The smart thermostat is just a two wire unit so the wires could be joined to create a permanent live connection for the boiler. Ensure that you isolate power from the heating system before undertaking this!