Quick background... 19 year old Ruud heatpump died in July (on the hottest day of summer, of course). The Ruud worked well for many years with a Honeywell CT3611(R4450) thermostat. Replaced the dead Ruud with a lightly used Goodman 2 ton unit (GSH130181).
Since that hot day in July, I've been...
We want to add another thermostat for the downstairs of the house. We have one for the upstairs already. We think we know the wire that goes to the thermostat but won't know until we cut it. It just looks like a brown wire now. How hard is it to add another thermostat to the furnace?
Thanks in...