Barthmobile Portal
thermostat upgrade

This topic can be found at:
https://www.barthmobile.com/eve/forums/a/tpc/f/3431087061/m/1003968697

01-20-2022, 11:12 PM
R2V2
thermostat upgrade
I am wanting to upgrade my 1995 analog thermostat with a digital. Does anyone know what would be the best thermostat? My system is gas heat/AC and a Honeywell fan controller connected to it as well. See picture


01-21-2022, 07:48 AM
Steve VW
It looks like you have the older style, which is good. The newer digital ones are expensive, prone to failure and are connected by a ribbon cable to circuit boards in the slave device so you can't use a simple switch type.

If yours is just a simple switch type you should be able to replace it with a standard heat/cool home type. One pair of wires to the furnace, another to AC. You should be able to keep using the fan controller in line.

I replaced the one in my Monarch with a Honeywell home unit. I did have some problems with the furnace, though. That furnace used the stat to switch full power to the furnace which included the ignitor circuit board, the gas valve and the fan motor, prob about 5 amp load. The modern units are only rated at 1 amp. I just installed a small relay in the furnace to switch the power on and off, then the thermostat only had to trigger the relay coil. Not sure the model#, unit is not labelled.

This one is used for furnace only. I have separate stats for the Atwood ACs


01-21-2022, 08:47 AM
Steve VW
Here is the relay I installed, to the left of the power switch. It switches the main power wire, using the thermostat wires to trigger only the relay coil.


01-21-2022, 08:48 AM
Steve VW
Here is a link for one I used to replace a Hydroflame stat in my 86 Regal. It shows model #. I did not install the relay on that one and it worked fine.

I used this one for furnace only but it has both heat/cool functions.

https://www.barthmobile.com/eve...193991267#8193991267
Good luck with your upgrade! Mechanic


9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
01-23-2022, 05:40 PM
R2V2
Thanks for the information Steve I really appreciate it. Ill let you know what I decide and post pictures.

quote:
Originally posted by Steve VW:
Here is a link for one I used to replace a Hydroflame stat in my 86 Regal. It shows model #. I did not install the relay on that one and it worked fine.

I used this one for furnace only but it has both heat/cool functions.

https://www.barthmobile.com/eve...193991267#8193991267
Good luck with your upgrade! Mechanic