While you wait for answers, we may have found some information which could help you.
Click here for Hot Water Keep Going Hot Cold
How do i stop the time from flashing on the Siemens RDJ100RF?
Worcester boiler dripping water?
Siemens RDJ10RF thermostat problem?
Greenstar 24Ri boiler, fast flashing - can I reset?
Vaillant ecotec 831 plus?
Oil fired boiler thermostat?