Siemens boiler?

I have a Siemens boiler RCR10/433-GB. The handheld controller is RDJ10RF. The hand held controller is fine but the box on the wall won't do anything when i press the overide button. The green light is on but all through the day the amber light has been on as well.
I've tried turning everything off at the mains and pressing the overide button but the boiler is not turning on & my radiators are not heating up.
Haven't explained very well but has anyone got any ideas? Thanks