Compatibility - heat pump

[Jimbo170412]

I have a York heat pump system, Model MV16CN21CC, which is currently using a "Communicating Thermostat Control".  4 wires designated A, R, C and B.  On the circuit board they go to A, R, C and B terminals.  I dont think this is compatible with the nest.  The circuit board also has an unused terminal strip labeled "thermostat controls" with the designations that match the nest thermostat.  W1, W2AUX etc.  Would I be safe in just switching the thermostat wires to these terminals to use the nest?  Is 4 wires enough?  Which terminals would I use for a heat pump?  

I am primarily switching to the nest to get scheduling which the current thermostat does not provide.

Any help would be greatly appreciated.

[Houptee]

Yes you can switch the wires to the standard screw terminals.

Do you have a 2 stage heat and 2 stage cooling system? You need to figure out if you do by looking up the model number.

This is important because you would need wires to Rc OB G and W1 W2 and Y1 Y2 and best to also connect a C wire.

So 8 wires if it's 2 stage heat and cooling.  6 wires if it's single stage.

[Markjosephp]

Hello folks,

Thanks for helping, @Houptee.

@Jimbo170412, I hope you've got the answer you're looking for. Have you had a chance to install your new Nest Thermostat? If you're still in need of assistance, feel free to let us know.

Regards,

Mark

[Jake]

Hey there,

I wanted to check in and see if you are still in need of any help. Please let me know, as I would be happy to assist, and answer any questions you may have.

Best regards,
Jake

[Jake]

Hey there,

I wanted to check in, and let you know that I will be locking the thread in 24 hours.

Best regards,

Jake

[Jimbo170412]

Thanks for the replies.  Turns out I do have a 2 stage heat pump.  But I only have 6 wires coming out of the wall.  Decided to make due with the existing thermostat and return the nest.

[Jake]

Hey there,

I understand returning the device, and am sorry that things didn't work out. With you no longer having the device, I am going to go ahead and lock the thread at this time. If you have any questions from here, please feel free to create a new post.

Best regards,

Jake