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View Full Version : New thermostat wiring = no a/c


charonx3
Dec 12, 2008, 12:06 PM
I am switching my totaline therm with a honeywell basic thermostat... when I rewired and put in the honeywell the electric heat works however the a/c handler does not even turn on and the fan does not run independently as it should have either system if I choose

The previous wiring was set up as W O G R C Y with white - W, O had no wire, G - green, R - red, C - blue, Y - yellow

On the new therm there was Rh, Rc, W on one side and Y, G on the other... I put red to Rh, blue to Rc, white to W and then yellow to Y and green to G

Heat works and blows fine, nothing else happens when I turn on the air or the fan

I have central air and electric systems on both... not sure if I just have a wire crossed or what

dac122
Dec 12, 2008, 02:22 PM
Looks like blue was your neutral common on the old tstat. I think you just need to switch that blue to your neutral common terminal on the new honeywell, and jumper the Rh and Rc together with a small wire. That should allow current to flow through to energize Y.

KISS
Dec 12, 2008, 04:10 PM
Rc and Rh gets jumped together and becomes R and would then be connected to RED only.

charonx3
Dec 12, 2008, 04:17 PM
Looks like blue was your neutral common on the old tstat. I think you just need to switch that blue to your neutral common terminal on the new honeywell, and jumper the Rh and Rc together with a small wire. That should allow current to flow thru to energize Y.



Do I just tape off the blue wire if there's no other terminal and run the jumper

KC13
Dec 12, 2008, 05:42 PM
If the new t-stat does not require a "c" connection, do not use the blue wire-clip the bare end off & tape it.