I'm having trouble with the heating function of our Honeywell RTH 230B. I have the following wires: Red, White, Blue, Green. I have hooked up the wiring to the following:
RH - Nothing (Jumperd)
RC - Red
W - White
Y - Blue
G - Green.

When I turn on the heating nothing happens, even when I turn on the fan. When I turn on the AC it works. I have tried several combinations and I still can't get the heat to work. Please help someone help!! Im Freezing!!

Thanks
Tawn

You mean the red wire is connected to RC, and then jumpered to RH? If so, it should work. Go to the furnace, and jumper the R and W terminals. If the furnace fires up, the problem is in the wires or the thermostat. If it doesn't, the problem is in the furnace.