Thermostatic Controls - Replacing Totaline thermostat with Honeywell RTH230B

I am replacing a Totaline P374-0200 thermostat with a Honeywell programmable Thermostat model number RTH230B. It controls a Desert Series Goodman air conditioner CLJ 30-1 as well as a gas furnace. There are 5 wires coming out of my wall. They were connected to the Totaline as follows: White to W, Green to G, Red to R, Blue to C, Yellow to Y. The Honeywell thermostat has connections labeled: Rh, Rc, W, Y, and G.

Before beginning the installation, I removed the red jumper between Rh and Rc in the Honeywell thermostat because the Honeywell directions said that the "red jumper wire must be removed in 5 wire installations". I then connected the White to W, Yellow to Y and Green to G, I also connected the Red to the Rh and the Blue to the Rc. However, the thermostat would not turn on the A/C and moving the fan selector to "on" did not turn on the fan. I called the Honeywell installation help number and the person said to remove the blue wire from the Rc, tape off the blue wire - do not use it - and put the red jumper back in between Rh and Rc. I did this and now it seems to be working but I just wanted to be certain this is okay to do (that it is properly done) and that my heat will work in the winter. It is 114 here today so I don't want to try to make the heat start up to test this! Having no electrical experience I am worried that this is not a safe and just wanted to confirm that even though there are 5 wires coming out of the wall I should not use the blue wire and instead use the jumper wire. Any advice would be appreciated. Thanks in advance!

You now have a correctly wired thermostat. The blue (C) wire was a "common" wire that was necessary for the operation of the old thermostat and is not necessary for the new thermostat.

You can test the heat by placing the thermostat in the heat position and raising the temperature setting. Leave it in this position just long enough to hear the furnace start and then lower the temperature setting or place it back into the cool position.

I don't think it should be necessary to test the heat position as long as you turned off the power to the furnace while you were changing the thermostats.

Thanks Furd. What if I didn't turn off the power to the furnace? Could I have damaged something? Before I started I went out to the circuit breaker box and flipped the switch that was labeled A/C by the builder. But surprise to me, as I was installing the thermostat, once I dropped the jumper wire into the Rh and Rc holes the A/C started up! Is there something else that I should have turned off? Don't know if the breaker was mislabeled or what. When it cools down a bit tonight I'll try testing the furnace to see if it comes on - just don't have it in me to try that right now in this heat.

If you had the circuit breaker marked "Air Conditioner" off then most likely the only thing that started was the blower in the furnace. The A/C uses the same blower as the furnace to distribute the cooled air so it is necessary to turn off both the A/C and the furnace circuit breakers when working on either.

By not turning off the power to the furnace there is a slight possibility that you blew the fuse on the furnace control but if the A/C is working okay you probably did not blow that fuse.

I am doing this project tonight and all my questions were answered except for the fact that I have an orange wire coming from my wall too ....can I just leave this one unconnected????....It was originally connected to my old honeywell thermostat under "O"........

I am doing this project tonight and all my questions were answered except for the fact that I have an orange wire coming from my wall too ....can I just leave this one unconnected????....It was originally connected to my old honeywell thermostat under "O"........

Is your unit a heat pump? If so, then O needs to be hooked up again to O on the t-stat.

The model # you posted says it's not a heat pump, how old is it about?

If it's not a heat pump, then O is not used, unless you have a zone set up in the home (more than one t-stat on one system)