I have a blue wire being unused on both the furnace and thermostat. If I connect that blue wire on both ends will I have power?

Page one of the wiring diagram:

diagram page 1

Page two of the wiring diagram:

diagram page 2

What it looks like at the thermostat:

wiring at t-stat

How it looks at the furnace:

wiring at furnace

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1 Answer 1


You indeed should be able to connect the blue wire to the C terminals at the thermostat and furnace control board and have it all work without a hitch.

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