New construction: I have a 120 CFM fan/light combo in the main bath that I need to wire to the furnace. Have never done this before. The furnace people will wire up the timer at the furnace. I ran the normal 12-2 wire from a switch in the bathromm up to the fan (did the same for the light). I ran a 12-3 (W, R, B) from what will be the fan switch to the furnace area. Do I need a special type fan switch in the bathroom? Do I need to run additional wire from the fan switch in the bathroom to the furnace area? Is the 12-3 wire from the fan swith in the bathroom to the furnace all I need? We have the framing in, no insulation or wall board so this is the time to get the wiring right! Thanks

What?

What you trying to do, make the light come on every time the furnace kicks in?

I am just as confused as HK is. Wire a bath fan/light to the furnace? And I thought I have heard everything. Can't wait to see what this is all about.