I have a 3 stage hot water boiler system with three different thermostats in my house. I went to change out the first thermostat downstairs with a new digital that said it was compatible with a hot water system. The only thing is the wiring diagrams are different, the three wires I have on my old edwards engineering thermostat are W6 , R5 , and 4B .. Could anyone shed some light on which socket these wires go in on a new digital, or if this will even work at all. I really need to change it out because its hard to set accurately because the old lens is faded pretty bad.
Are they White-Rogers 1311 style perhaps? If so, 4 is power open, 6 is power closed, and 5 is common. But not all digital stats will work with these. You can call the tech support number on the literature and find out. Some stats will work after changing one of the settings in the setup program. White-Rogers has a digital that is compatible.