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krich22774 · Apr 16, 2006, 04:38 PM

I installed a RTH230B Thermostat this winter. Heat worked fine all winter. Went to turn on the air this week and it wouldn't come on. I have 5 wires (Red, Blue, White, Yellow, Green). The thermostat has connections for Rh, Rc, W, Y, and G.

I had the yellow wire in Rc and the blue wire in Y. I swapped those wires. So my connections are now Rh-red, Rc-blue, White-white, Yellow-yellow, Green-green.
My air came on after switching the blue and yellow wires, but it would not turn off. I had to go to the furnace unit and turn the main switch off to turn it off.
My father-in law looked at it and said that my red (Rh) and blue (Rc) wires were touching each other. So he took all the wires out and reconnected them to the same spots, making sure that no wire was touching the other. Now my air will not turn on at all nor will my fan using auto or manual. The heat still works.
Anyone have any suggestions what could be causing this. I don't want to drop several hundred $$ to have someone come out and do an easy fix. Thanks.

tkrussell · Apr 17, 2006, 03:21 PM

Need to know what the blue wire goes to in your system. The Honeywell RTH230B is a 5 wire, but 2 wires are both feeds, the Rc and the Rh.

There is no function in the stat for a blue wire, which usually is for a heat pump.

You will need to open the system's control panel, find the wiring diagram, make note of the stages of cooling, aux heat, reversing valves, and emergency heat, that may exist and find a thermostat compatible with your unit.

See if you can find the website for the manufacturer of your unit, there they may tell you which stat you need.

krich22774 · Apr 17, 2006, 05:21 PM

Thanks. I will admit. I am not very electric literate. I found my instructions for the unit (furnace) and it had a wiring diagram from the furnace terminal board to the thermostat. From the furnace circuit board to the thermostat, it had: Y to Y(which is my yellow wire), G to G (which is my green wire), W to W (which is my white wire), and R to R (which is my red wire that I have in Rh). They didn't show anything going from the C on the terminal board to anything on the thermostat.

Do I not connect my blue wire coming out of the wall (which I currently have going to Rc) to anything in the thermostat? And if that is the case, the thermostat came with a jumper for Rh and Rc. Do I use the jumper?

krich22774 · Apr 17, 2006, 07:00 PM

O.K. After some reading, I figured out that I should remove my blue wire from the Rc and use the jumper for Rh (red wire) and Rc.

So my configuration is:
Rh -red
Rc - jumper
W - White
Y - Yellow
G - Green

Blue wire isn't in anything now. Everything works EXCEPT the AC compressor doesn't come on outside. Is there a chance that maybe I should put the blue wire in the Y slot, or could this possibly damage something?

Also, when originally installed, my red and blue wires had some exposed wiring and the two were touching. Could that have damaged something to my compressor?

krich22774 · Apr 17, 2006, 07:13 PM

Still investigating. I looked at the terminal board on my furnace unit. Coming from the Y is a blue and red wire.

So would it be safe to hook the blue wire to the Y slot on my thermostat? I just don't want to ruin something by switching wires around and end up costing me more money.

tkrussell · Apr 18, 2006, 01:55 AM

Swap the blue for the yellow, seems that the yellow is spare,and blue goes to compressor relay. The red touching the blue did turn on the AC,correct? Did no damage, this type of short simulates a switch.

krich22774 · Apr 18, 2006, 01:23 PM

Thank You. It's working now.