[alex14]

I'm trying to change and old honeywell thermostat in my house, but I'm not really sure if I can only use and electrical one. I just bought a Honeywell # RTH 221B basic (heat & cool)programmable thermostat, to be use as a heat only unit... I attached a picture of my old thermostat to find out if they are compatible...

Thanks

[tkrussell]

I am moving this to Heating and Air Conditioning so you can get a better answer. There you will find a very good sticky note listing a great deal of information on thermostats.

You will need to post what type of heating unit you have.

[Steve1honeywell]

I am changing from a White Rogers manual zone thermostat to a Honeywell RTHB 221progammable thermostat and cannot match the wires. I have a Green(Y, of G), White(R or 5) and a Red(W or 4) wire. The various connectors are Y, G, Rh, Rc, and W on the new thermostat. Which old wires match the new. There is a jumber between the Rh and Rc -- should this be remived.
Thanks
Steve

[hvac1000]

If this system of your is a 3 wire White Rodgers zone system the thermostat you have will not work. What is the Exact model of your old thermostat.