I want to replace one of my old dial thermostats with a cm67. My central heating is zoned and this thermostat is wired via a sunvic 5203 valve, which requires a 'live' (easy), a 'valve open' and a separate 'valve shut' wire. Should I use terminal C (which is, by default blocked off) for the 'valve shut' ?
Opinions please....
Opinions please....