Boiler failure. Worcester Greenstar 37CDi boiler with Digistat controller sometimes fails to cut in or out on the Digistat thermostat, A faulty Digistat controller was diagnosed by a Corgi heating contractor, the controller was renewed, this was not the cause of the malfunction, as the boiler has failed on many occasions since. Despite the initial diagnosis, and my video evidence of failures, Corgi will not rectify the fault, as several heating contractor visits since have failed to diagnose the fault So I can’t leave the home, in case it freezes or overheats as no reliable control. Photo - controller receives signal to switch on, boiler fails to cut in (no flame light).