Trane 4TWR4 Heat Pump & XR402 Thermostat

[kobrad]

I have a Trane 4TWR4 Heat Pump and a XR402 Thermostat.  I need help knowing if it is compatable with a Google Nest Learning Thermostat gen3 (model #A0013).   And if so, can anyone help guide me to know which wires go in what slots on the Nest Thermostat?

Below are the slots and color wires that are currently wired into my XR402 thermostat

OT1 - brown (I think this goes to an outdoor temperature gauge and I can leave it out)

OT2 - black (I think this goes to an outdoor temperature gauge and I can leave it out)

R - red

W1 - white (there is also a copper wire from the W1 slot going into the W2 slot)

Y1 - yellow

G - green

O - orange

B - blue

[kobrad]

[Markjosephp]

Hello kobrad,

Thanks for considering switching to a Google Nest Learning Thermostat. Great choice! The compatibility between your current system and the Nest Thermostat seems promising.

Based on your existing wiring configuration on the thermostat, it should be a straight-forward installation for you on the Nest thermostat.

• Red wire to the Rc terminal.
• White wire to the W1 terminal.
• Yellow wire to the Y1 terminal.
• Green wire to the G terminal.
• Orange wire to the O/B terminal.
• Blue wire to the C terminal.

The OT1 and OT2 wires from your current setup don't have corresponding slots on the Nest Thermostat, so you can leave them unconnected. If you encounter any issues, let us know—we're here to help!

Best regards,
Mark