Duo-Therm 4 button thermostat problem

[Anniedanny]

Our Duo-Therm thermostat will not go into heat mode. It works on back A/C, but when depressing the mode button, it will not go on heat. Any ideas? Thanks in advance, Annie

[jlyon69]

Here is a trouble shooting guide for the 4 button CCC.

http://bryantrv.com/docs2/docs/ccc4.pdf

First, you probably want to do a re-set of the thermostat so a system re-scan will be done to find the 2 ACs and furnace. If it still doesn't "see" the furnace, it's probably the furnace data cable connection at the Zone 1 control box. Or, the data cable itself could be bad. I had a mouse take out both ACs and my furnace when he chewed through my thermostat data cable.

[rvgrandma]

You sure the back control is for furnace too? I guess since I have a 2000 Sea View it is different, but our back control only works the back a/c, not the furnace

[vito.a]

If anyone needs a 4-button Duo-Therm thermostat, I have one for sale here in the classified section of IRV2. Just refurbished. Looks and works like new.
I also have a 4-button AC control board.