Anyone else had trouble with the jumper links on the transmitter?
I just fitted one of these thermostats (to replace a faulty Drayton Digistat SCR receiver) and it looked ok. Everything seemed fine except that the receiver didn't respond to the transmitter - no green light on the receiver. I removed all the jumper links (which seemed remarkably loose) on the transmitter, and reset all the dip switches to the "up" position to match. Immediate green light and the boiler fired up. Suggests a dodgy link connection to me.