2 wires for both heating and cooling systems

[Andy66]

Hi

My old thermostat is Totaline P286-1600 which have only 2 wires but control for both heating and cooling systems. The two wires labeled Y2 (a bit yellow) and RH (black). How to I connect to my new Nest Learning Thermostat?

[Markjosephp]

Hello Andy66,

Thank you for taking the time to let us know about your inquiry. I'd be happy to take a look at this for you.

Could you share a photo of your current thermostat's wiring? Also, you could try our Compatibility checker to see if your current system is compatible with the Nest Thermostat.

Regards,

Mark

[Jenelyn_O]

Hi there,

I wanted to follow up if you still need help. Please let me know if you’re still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Best,

Jenelyn

[Jenelyn_O]

Hello there,

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.

Thanks,

Jenelyn

[Andy66]

Hi Jenelyn,

I already describe my problem. What kind of additional information do you need?

Regards

Andy

[Jenelyn_O]

Hey Andy66,

Thanks for the update and for the photos you sent. In the Nest Learning Thermostat, Y2 terminal is for second stage cooling and RH terminal represents a terminal for power. If you have both a heating and cooling system, you must have a separate wire for both of them to be connected to the Nest Learning Thermostat. To check it further, could you please share a photo of the wires connected to your control board? 

Regards,

Jenelyn

[EmersonB]

Hey everyone,

@Andy66, I'm dropping by to ensure that everything is covered here. How's it going with your Nest Thermostat? We would appreciate it if you could share the information we're asking above. We'd be glad to hear from you.

Thanks for lending a hand, Mark and Jenelyn.

Regards,
Emerson

[EmersonB]

Hey Andy66,

Just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, we would be happy to keep it open. If there's more we can do, just let us know.

Best,
Emerson

[Andy66]

Hi Mark,

Attached is the current thermostat wiring.

Best regards

Andy