Wiring new Thermostat to new furnace
 

Hello, I installed a new trane xr90 furnace and would like some help wiring the thermostat. I dont want to short out the board or anything. My furnace has the following connections. C, G, R, W, & Y. I am hooking that to a RTH7000 Honeywell programable thermostat. I will only be using Single stage heat for now but airconditiong in the future. I bought a five conducter themostat wire with G R W Y and Blue. There wasnt a blue on the furnace. Do I just need to hook up G, R W & Y to their prospective spots. Do I need the C terminal and what is it used for? Thanks for all your help.

C is common, if your t-stat has that on it, than you can use it. not sure if your t-stat requires it or not. some do, some dont.

Thanks, I just hooked everything up by color and it worked. Why do they use a jumper from RR to R on the stat

If it's got a C (common) you'll need to power the stat. It runs of the furnace xfrm (transformer)

You mean RC and RH? incase you have a dual transformers, one for heating, one for cooling.

Ok, that makes sense. All is working ok. Thanks

... and because most setups use just one transfomer the tstats often come jumpered from the factory.

Thanks for the extra explanation. :thumbsup: