where to connect spare gray wire

[rbulkley]

My old thermostat has a spare gray wire currently in slot labeled L.  I am not sure where to connect in my  Nest.  I have a geothermal system with heat pump.

[Patrick_Caezza]

@rbulkley 

The L terminal is usually for a lamp indicator and isn't used on the Nest. You can just tape it off

[rbulkley]

Thank you