I just replaced an old digital thermostat with a new programmable honeywell. The wires coming out of the wall are as follows:
Red
White
Blue
Green

In the old thermostat they were connected as follows:
Red:Rh (jumpered to RC)
White:W
Blue:Y
Green:G

The unit is a gas heater/AC unit. I called honeywell about this but just want to double check. The new honeywell unit does not have an RH or RC terminal, just an R. Honeywell told me that I don't have to jumper in this new unit because just plugging the red wire into the R terminal will take care of it. They said it would only be problematic if I had separate wires coming into the house to the RH and RC terminals. The heat is running fine right now so I feel they are correct. Do I need to just put the old unit back up or are they correct?

Do I need to just put the old unit back up or are they correct?

If the new thermostat is functioning properly I see no problem. You do not have separate R terminals to worry about so stop worrying.

Great. Thanks. My concern I guess is whether it will affect the AC when we run it. I would test it but since it is below zero out the manual recommends against that.