One of my wireless digistat controllers has been damaged during the boiler service. The unit - when power is applied to it - now flashes the red light rapidly and constantly (for hours)- twice as fast as when pairing or receiving a signal- and it cannot be taken out of this mode. Receiver obviously doesn't sync to it. Overrides don't work also. Clearly faulty, but can't seem to find out what the fault is on any faultfinding guide - could it be the capacitor ? Is the unit repairable or do I need to get a new one ?