Have a International Comfort Products (Canada) Model OLB5-R059-085-3/BLR-5/OLR105A12B warm air furnace installed new 2005 with 2-wire connected (terminals R&W) thermostat and want to replace thermostat with NEST Gen 3 Learning Thermostat but not sure which Terminals on NEST t’stat to connect. And if I also need to connect third wire from furnace C term. to Nest t’stat C terminal to keep Nest t’stat onboard battery charged.
Contractor’s Assistant: Have you replaced any part of your furnace before? If so, how long ago?
Contractor’s Assistant: How long has this been going on with your furnace? What have you tried so far?
Has WHAT been going on?