While you wait for answers, we may have found some information which could help you.
Click here for Heating Controller BoilerSiemens RDJ10RF thermostat problem?
Have I got got a faulty programmer?
Siemens brtrf keep LOSING connection?
red flashing button siemens RCRIO/433?
Rdh10 & RCR10/443-GB by seimens?
my rdh10rf siemans thermostat will not send signal to my boiler. ?