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I have an older furnace, on the switch block I have Y,C.W,R and an unlabeled screw that connects to the shut off it looks like. I need to hook up a thermostat that needs the C wire. I have a spare wire, in the bundle which I hooked up to the c terminal downstairs, from these videos that I've seen it tells me to then bridge the Y and G together, I do not have a G on the block, what do I need to do to get the neutral wire set up
Cwire, if it's attached to theCterminals at both ends. It sounds like you're not sure what you're doing, you might want to contact a local HVAC technician before you fry your furnace. – Tester101♦ Mar 7 at 17:37