Check out some similar questions!

johnjjacks · Sep 25, 2007, 08:35 AM

Installing a new Honeywell thermostat to a Carrier system . Old thermostat was already removed before I got there. Wires from the wall are Red,Blue,White,Yellow and Grenn. Thermostat terminals are RH,RC,W,Y,G. I currently have it rigged up as follows

Red to RH
Blue to RC
White to W
Yellow to Y
Green to G

Only the AC works in this configuration, no heat.. What have I done wrong?

Thanks for anyone that can help..

NorthernHeat · Sep 25, 2007, 01:48 PM

Hope this helps. https://www.askmehelpdesk.com/heatin...tml#post268211

johnjjacks · Sep 25, 2007, 01:55 PM

Originally Posted by johnjjacks

Installing a new Honeywell thermostat to a Carrier system . Old thermostat was already removed before I got there. Wires from the wall are Red,Blue,White,Yellow and Grenn. Thermostat terminals are RH,RC,W,Y,G. I currently have it rigged up as follows

Red to RH
Blue to RC
White to W
Yellow to Y
Green to G

Only the AC works in this configuration, no heat.. What have I done wrong??

Thanks for anyone that can help..

So , if I understand , take the blue off RC , and leave it out , and use a jumper across RH /RC?

NorthernHeat · Sep 25, 2007, 07:58 PM

That is most likely correct. Open the furnace and see if blue is connected to anything.

KISS · Sep 26, 2007, 07:03 AM

And as a post:

Don't you mean disconnect red and (jumper RH to RC and connect to blue)?

Since Cooling works, blue must be correct since it's connected to Rc. Red hopefully doesn't go anywhere. Red should normally be connected to R or (Rh and Rc), but since heat doesn't work something is amis or miswired.

Blue might be second stage cooling, but since heat doesn't work and it's connected to red, this doesn't make sense either.

NorthernHeat · Sep 26, 2007, 09:25 PM

No I mean connect red to RC and RH, blue is probably nothing but just in case I asked him to find out what it (blue) was connected to on the PC board or in the furnace. I won't stoop to berating your last post.