Nest thermostat wiring

[Thermostat]

When ever you are troubleshooting the thermostat wiring on a Nest thermostat it is always nice to have a basic electrical meter like this one. The Nest thermostat has press connectors for the thermostat wiring connections. The press connectors are designed for only one wire each. If your existing thermostat had a jumper between RC and RH do not install a jumper between the RC and RH terminals on your Nest thermostat. The Nest thermostat automatically internally connects the RC and RH terminals if needed. Below are typical Nest thermostat wiring diagrams for air conditioning and heat pump HVAC systems. The wiring colors shown below are typical. Your thermostat wiring colors may not be the same color. You can use this thermostat wire.



Update amazon now offers a free smart home consultation

Typical Nest thermostat wiring diagram for a 1 cool 1 heat HVAC unit

Typical Nest thermostat wiring diagram for a heat pump unit

[Servicetech]

How does Nest thermostat call for AUX heat when it gets too cold for heat pump to keep up?

[hvactechfw]

it calls for aux heat the same way a standard HP thermostat does which is staging differential.

[Servicetech]

Does the Nest not use the W1 to call for AUX heat like a conventional stat?

[Thermostat]

I will try to come up with a way to update the heat pump diagram. The unique thing about the Nest is that it can sense if there is a wire connected to W1 or Aux and determin which terminal to entergize for back up heat.

Nest Learning Thermostat, 3rd Generation, Works with Amazon Alexa

[Servicetech]

Does the Nest have a way to "lock out" AUX heat above a certain temperature like most high end stats? How about locking out Condenser below a certain temp?