[khol56]

My Honeywell thermostat battery was low. In removing the thermostat, I did not realize that there were two screws holding it to the baseplate. Therefore, I yanked it out of the wall and noticed sparks where the wires were connected to the terminals. I finally removed the thermostat and replaced the batteries. When I reinstalled the thermostat, it did not work. The heating, cooling, and fan were not coming on. I purchased a new Honeywell thermostat I connected the new thermostat. This one did not work either. The old thermostat model# is CT8602C. The terminals are O, W, G, C, R, Rc, B, Y. The new thermostat model# is RTH110B. The terminals are Rh, Rc, W, Y, G.and there is a jumper between Rh and Rc. The wires coming out of the wall are Red, Yellow, White, Green, and Blue. On the old thermostat, the white wire was connected to terminal W, the yellow wire was connected to terminal Y, the green wire was connected to terminal G, the red wire was connected to terminal R, and the blue wire was not connected. I believe, there was a jumper between terminals R and Rc. On the new thermostat, I connected the white wire to terminal W, the yellow wire to terminal Y, the green wire to the terminal G, the red wire to terminal Rc and Rh (there is a jumper between the two), and the blue wire is not connected. Please let me know what the problem is. Why the heating and cooling no longer work.

[dac122]

You may have caused a short that blew a fuse or fried the transformer in your air handler/furnace.