Help Wiring New Thermostat
My current battery-powered thermostat has 3 wires (see photo). I believe these to be: 1 for furnace, 1 for fan alone, and a common. These wires are connected to the furnace control board as shown in another photo. None of the wires are always live, and I need a 24V supply for the new thermostat. Page 13 onward of the furnace manual covers wiring up a controller. Strangely it details using a different connector block to the one that is being used now.
At this point I have acquired 50' of 18/5 thermostat wire and intend to replace the current wire. However I need some advice on how exactly I should wire it up at either end.
Link: user manual for the new thermostat .