Have a honeywell ct3500a4453 thermostat and want to connect a new rth6350d
Replacing old honeywell CT3500A4453 THERMOSTAT with a new RTH6530D where does the bluw wire go on the new unit?
Comment on mygirlsdad77's post
The blue wire connects to a black wire coming from a relay? O power supply? Inside the furnace.The blue wire at the old unit was connected to "B".
Comment on mygirlsdad77's post
Thanks for the reply; I actually just purchased another thermostat (3M brand) that has the "B" connection like my old one... Problem solved! Too bad tech support people from Honeywell had no clue as to how to take care of this!