While you wait for answers, we may have found some information which could help you.
Click here for Siemens Rdj10rf Boilercan i fix it honeywell st1000 ?
Hot water but no central heating?
Honeywell ST7100 programmer goes blank when RUN selected?
How do I reprogram my ideal bolier rf thermostat receiver?
isar he30?
heating, Oil boiler not running?