I've moved the thermostat to another location, in doing so I did not disconnect power to the unit and fear that I may have shorted some of the six wires and damaged a circuit board. I heard some relays engaging when I pulled the thermostat wires thought the wall. I've checked the thermostat with my neighbour's (similar unit) and it works fine. All fuses all OK. Pilot light is ON. I have the right voltages at the thermostat terminals. Any ideas where to look will be much appreciated.