I replaced a old round thermostat with a programmable thermostat. I have two sets of wires coming out of the wall. One single red wire, and a group of wires that are red, white, yellow, and green. I connected them according to the instructions, but obviously that was not right. The single red wire is connected to Rh, and the group of wires are going to Rc, W, Y, and G. The red wire in the group is going to Rc, the white wire is going to W, the yellow wire is going to Y, and the green wire is going to G. Can some body tell me what I did wrong? Thank you.

Where was the single red wire connected on the old thermostat?

What are the wires at the airhandler wired to

I don't know where the single wire was wired to before. I would assume it was also wired to the Rh on the old one also. I'm sorry, I don't know what a airhandler is.

Air handler is the inside unit or furnace.Open the panel and you will see the wiring coming from the thermostat. Be careful what you touch inside there as there is live voltage