Wiring Compatibility

[TC67]

I have a 20-yr old Heat-AC air handler with gas burner and outside condenser feeding AC coil. No heat pump, no emergency heat, but 3 zones -2 t-stats upstairs as slaves to the main floor T-Stat. The Nest Learning App tells me to “look closer” given the wires I’ve tagged. The main floor t-stat is not original, but fully functional as wired. see photo. 

need help resolving a wiring scenario for Gen3 Nest Learning. Thanks. 

[Patrick_Caezza]

@TC67 

If you have three zones, you probably have a zone controller installed close to the furnace. Post a picture of its wiring, please.

If it is the zone controller that I think it might be, it is not compatible with any of the Nest thermostats and will only work with a specific thermostat, and it requires both the O and B valve reversal wires, which are not supported by the Nest thermostats.

[TC67]

This would be very disappointing, as the only way to truly discover this was to open the box and dig into the install. There’s no was to rewire my zone panel? 

[Patrick_Caezza]

@TC67 

You have the zone control panel that I was afraid you had.

You must use the provided thermostat for the zone 1 thermostat.

You can use any thermostat for zones 2 and 3.

[Jake]

Hey there,

Thanks for the help Patrick_Caezza.

I wanted to check in and see if you managed to see Patrick_Caezza post. Please let me know if you have any questions from here. I would be happy to assist, and make sure you are good to go.

Best regards,
Jake

[Jenelyn_O]

Hi there,

Checking if you still need help. Please let me know, as I'll be willing to assist you further. 

I appreciate your help, @Patrick_Caezza and Jake.

Thanks,
Jenelyn

[Jenelyn_O]

Hi TC67,

We haven't heard from you in a while so we'll be locking this thread if there is no update within 24 hours. If you need assistance or want to discuss topics, feel free to start a new thread.

Regards,
Jenelyn