Is my wiring compatible with Nest 4th Gen Thermostat

[Rouster]

I have a LUX PSPH521L Thermostat.

Wiring is a follows.

W2 - AUX Heat Relay

G    - Ran Relay

O    - Cool Changeover Valve

Y     - Compressor Relay

R     -  L1 (HOT)

C    -  Common

E     - Emergency Heat Relay

I have checked the compatibility of the 4th Gen Nest and it says the 4th Gen Nest will work, but it does not have a place for the "E" wire.  Can you tell me if I need this wire or can I just cap it off and not use it? 

Thank You

[CoolingWizard · Accepted solution]

@Rouster ,

The Google Nest Learning Thermostat Gen 4 can indeed support both the Auxiliary Heat and the Emergency Heat.  
On you old thermostat you should find a wire on W/AUX and a wire on E.  For the Google Nest Learning Thermostat Gen 4 the W/AUX wire will attach to the W2/AUX terminal.  And the E wire will attach the Gen 4 star “ * “ terminal. 

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AC Cooling Wizard

[Rouster]

Thanks for the reply, 

answered my question completely.

Appreciate it very much.