2 wire thermostat

[Maliks]

Hello,

I have currently installed Honeywell 2 wires thermostat and would like to know if I can use the same wires and install nest model #G4CVZ?

thanks,

[CoolingWizard]

This actually depends. On a typical two wire system on an older furnace style, the two wires are simply a connection to cause the gas valve to turn on and they operate at 500 to 700 mA of current. The nest requires a more conventional unitary system that operates on 24 V of AC power. What you need to determine is the other end of the thermostat wire at the furnace in where it connects. If it’s connecting directly to the gas valve, then no nest will not work.

Ken, the AC Cooling Wizard

[Maliks]

I think it is connect to valve. There is any other way I can install nest?

[CoolingWizard]

If there are additional conductor wires in the thermostat cable behind your thermostat base, that are not being used, and if your heating system has a 24 V AC transformer, then, yes, it would be possible to use a Nest to control that system.

Ken, the AC Cooling Wizard

[aatienza]

Hey there,

Maliks, checking in — we hope you've got the answer you're looking for. Let us know if you have more questions in mind.
 

I appreciate the help, CoolingWizard.

Thanks,

Archie

[aatienza]

Hey folks,

I just wanted to follow up to see if you still need our help. Please let us know as we would be happy to answer any questions you may have. 
 

Thanks,

Archie

[aatienza]

Hello there,

Just checking in to make sure that you've seen our responses. Please let me know if you have other questions or concerns as I will be locking this in 24 hours if I won't hear back from you again. Feel free to start a new thread and we'll be happy to help.
 

Thanks,

Archie