Need help installing Nest Learning 3rd gen to a PTAC Heatpump 2H-2C (C, W, Y, B, Gh, Gl, R)

[mcny]

Hello,

I would like to add a Nest Learning Thermostat to my currently remote-less GE AZ55H15DADM1 Zoneline 2-stage Heatpump PTAC unit.

Only one terminal on the PTAC has a terminal that directly corresponds to the terminals on the Nest. The others, not so much. I tried Nest's technical support and the help they could provide was a little limited.

PTAC	Nest	Function (from Manual)
R		Red - 24V AC Only
GL		Green - Low-Speed Fan
GH		Green - High-Speed Fan
B		Black - Solenoid
Y		Yellow - Compressor
W		White - Heater
C	C	Common - Ground

If anyone can point me in the right direction, it would be most appreciated.

Kind regards,

MC Y

[mejiacruz]

Hi @mcny,

I’m really sorry that installing your thermostat is getting longer than expected. Due to the unique wiring configuration of your heat pump system, particularly the 2-speed fan, we recommend consulting a professional technician for proper configuration. This recommendation is based on this article in the Google Help Center.

If you are able to complete the installation please let us know.

Regards,

Josh