Ok this started over in another thread and the conversation really didnt belong there
I currently have a Carrier Comfort Zone II thermostat that I am trying to find a way to replace with a smart thermostat - i would love to go EcoBee but hell I’ll take any suggestions - and EcoBee was not confident that my set up is compatible
Anyone have suggestions?
Thermostat Comfort Zone II (Two Zone programmable)
Unit Near Furnace*
Inside Cover
Did you ever get an answer to this? I have the same thermostat and system with two zones and would like to go with a wifi smart thermostat. I bought the TC-WHS01 (Carrier Comfort Wifi Thermostat) but it has not come in yet. Looking at the wiring, I hope I didn’t just waste my money.
Let me know if you found anything out, I did find out for sure that the Nest (that I brought from my last home) won’t work at all with this type of zoned system.
Thanks in advanced.
Nope havent found anything - Were you able to get the WHS01 set up with the unit?
If the HVAC unit wasnt only 10y old I would rip and replace whatever I needed to … but I was told by “the boss” not to even think about it … and WAF is of primary import 
If that WHS01 works, then I may replace the current thermo with it and see if I can hack together a way to connect it up to Hubitat/ST
@JohnHoke I have the same set up, wondering how you resolved the issue. I am looking at the honeywell HZ322 control board.
Hello, Im an HVAC technician. saw that you guys never received an answer so created an acct to answer you all. In order for you to change to a newer tstat you would have to replace the zoneboard with a honeywell zoneboard (compatible with almost any tstat) and then rewire each tstat as they could be smartwired where they only have 3 wires for all the signaling vs 5 wires for heat pump and 4 for straight cooling systems/furnaces. Hope this helps, cheers
Never got notifications on this but the tstat I bought didn’t work. Thanks for the updated info, might look into the honeywell board.
There are serious drawbacks to upgrading this to an 5 or more wire thermostat system. The Comfort II system only needs 4 wires to the thermostat (Pwr, Gnd, Data, Clock) to operate. Since most installers chose the cheap prewire option and only used 4 or 5 wire to the thermostat. And since all the zones are controlled from this main thermostat, and the system is supplied temperature information from thermocouple devices in each zone which only required 2 wire bell cord. To upgrade, the whole system must be rewired. Or a Bluetooth or WiFi capable solution needs to be installed.
I tried upgrading 10 years ago after my system was damaged by lightning but wasn’t able to find anything that I could adapt to my 3 zone 2 story home. Since with all other options each zone requires a 5 or more wire thermostat system I was able to place one thermostat on a wall next to the air handler closet on the second floor, and a second thermostat in place of the old primary on the first floor using the existing 5 wire. Which was not optimal and I wound up switching back to the old system because of the loss of one zone and uneven cooling.
I have made a habit of picking up used controllers and thermostat boards to keep my system running for 23 years because lightning is a problem here.
