I'm trying to connect my new thermostat to my Icon 23T boiler. Thermostat is of volt-free type and the boiler MIs say there should be a "white external controls cable" that is bridged for connecting a thermostat.
All makes sense. I've opened the control panel to expose the PCB and there is a white two core flex cable. One terminal connected to the built in timeclock, and the other going to a multiplug.
The thing is, the other end of this cable is connected to what looks like the ignition module. If I unplug it from there, the boiler fails to spark.
I'm totally confused. This is the only cable that the MIs refer to. The only other white wires go to a temperature sensor on one of the flow pipes.
Any ideas where to start? Maybe the white cable I describe should just be free ended when a thermostat is not in use, but someone connected it up to the ignition module? The thing is, this cable is really long and just looks like it should be for an external thermostat control unit.
I can get some pictures of the board if that helps?
All makes sense. I've opened the control panel to expose the PCB and there is a white two core flex cable. One terminal connected to the built in timeclock, and the other going to a multiplug.
The thing is, the other end of this cable is connected to what looks like the ignition module. If I unplug it from there, the boiler fails to spark.
I'm totally confused. This is the only cable that the MIs refer to. The only other white wires go to a temperature sensor on one of the flow pipes.
Any ideas where to start? Maybe the white cable I describe should just be free ended when a thermostat is not in use, but someone connected it up to the ignition module? The thing is, this cable is really long and just looks like it should be for an external thermostat control unit.
I can get some pictures of the board if that helps?