I am installing a new programmable thermostat (Hunter 44860) but would like to have it use the household electricity and not just run off of the batteries. My current thermostat is a 3 wire setup (Y-RC-W, with jumper from RC to RH). I plan on running another wire to connect the common leg to C on the thermostat, but where does it connect to? Currently the RC wire is connected to a 24V transformer off in the basement. Thanks in advance for any help.
On your furnace transformer there is a hot (R) and common (C). Put your new C on the opposite terminal to the RC on the transformer or the C on the circuit board. The return from the AC also has to go to C so you can trace it back from there.
"Cut it twice and it is still too short". To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.