The current thermostat (Honeywell digital) has 4 wires w,y,g,and r. But the y is also actually green. I wish to put in a programmable. Does it need to be 4 wire? The system is a/c and gas forced air.
Thx
Lance

Great explanation of thermostat wires at https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html
If you only have 4 wires, look for a battery powered one or voltage stealing.

Great explanation of thermostat wires at https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html
If you only have 4 wires, look for a battery powered one or voltage stealing.

Thanks Labman. My old Lab, Odie, died a few years ago and I think of him this am as I read your handle. They are good memories.

Just to confirm so that I don't burn out the system: The following is probably true... R=hot to thermostat,W=heat,Y=cool,G=fan. And I can use any programmable thermostat that is designed for these 4 wires and is battery assisted or steals voltage? Or both... or is it one or the other?

TIA, and where's the book, Thermostats for Dummies?

I have 4 wires coming from my furnace a green, a red, an orange and a white on my new thermostate it has a green , red, yellow , white connections where do I put the orange one...

I have 4 wires coming from my furnace a green, a red, an orange and a white on my new thermostate it has a green , red, yellow , white connections where do i put the orange one.................

To what terminals on the furnace are each of the wires connected?