Nest thermostat compatibility

Use our interactive tool to tell if your system is compatible, and which Nest thermostat models work with your system.

To learn more about heating and cooling systems including zoned, proprietary, dual fuel, and high voltage systems, read below for more information.

System types that are Nest-compatible

The table below summarizes systems that are generally compatible with Nest thermostats, however, you need to use the online Compatibility Checker for an accurate answer about what works in your home.

Google Nest thermostats are designed to work with most 24 V systems. They work with all common fuel types including natural gas, oil, and electricity.

System types	Nest Learning Thermostat (3rd gen or earlier)	Nest Thermostat E	Nest Thermostat	Nest Learning Thermostat (4th gen)
Heat only, cool only, Heat+Cool			C wire or Nest Power Connector required
Natural Gas, Oil, or Electric fuel types
Single stage heating and/or cooling			Heat only or cool only C wire or Nest Power Connector required
Single stage heating with two stages of cooling
Two stages of heating with one stage of cooling
Single stage heat pump with or without AUX heat			C wire or Nest Power Connector required
Single speed fan
Single stage heat pump with separate single stage furnace heating (Dual fuel) ¹			C wire or Nest Power Connector required
Single stage heat pump with separate two stage furnace heating (Dual fuel) ¹
Two stage heat pump with or without AUX heat
Two stage heat pump with separate two stage furnace heating (Dual fuel) ^{1, 2}
Humidifier* or dehumidifier ^{1, 2}
Humidifier and dehumidifier^1,3
Dual transformer systems ^{1, 2}
Two stages of cooling and two or three stage furnace heating ²
Two or three speed fan ^{1, 2}
PTAC systems ²
Ventilation systems
HVAC power compatibility

¹Your system requires advanced configuration and wiring. If you have one of these systems, contact a local professional.

Important: Professional installation is recommended for some systems since their wiring and setup can be complicated. These include:

Dual fuel systems (heat pump with furnace)
Dual transformer systems (Systems that have more than one R wire)
Whole-home humidifiers and dehumidifiers (compatible with Nest Learning Thermostat only)

² Nest thermostat can only support one of these systems at a time.

³ Nest Learning Thermostat (4th gen) can support humidifier, dehumidifier or ventilation on AQ+.

Compatibility with zoned systems

Nest thermostats are compatible with zoned systems, including zoned systems with dampers. However, there are some zoned systems that require a C wire to work with a Nest thermostat. For more information, go to How the Nest thermostat works with zoned systems.

About the Nest thermostat’s star terminal

Nest thermostats also have a star terminal * that offers you some flexibility to install specialized systems.

The Nest Learning Thermostat’s (3rd gen or earlier) * terminal lets you install a humidifier, a dehumidifier, emergency heat, multiple fan speeds, or a 3rd stage of heating.

The Nest Learning Thermostat (4th gen) has the AQ+ and AQ- terminals which offer flexibility to install a humidifier, dehumidifier or ventilation system.

If you have a 1-wire humidifier, dehumidifier or ventilation system, you can connect it solely to the AQ+ terminal with no wire in AQ-. This means that the thermostat provides power to the humidifier, dehumidifier or ventilation system by shorting R to AQ+.

If you have a 2-wire humidifier, dehumidifier or ventilation system (also referred to as an externally powered humidifier, dehumidifier or ventilation system), you can connect 1 wire to AQ+ and the other to AQ-. In this case the thermostat does not provide power to the humidifier, dehumidifier or ventilation system. To turn it on, the thermostat simply shorts AQ+ to AQ-.

The additional AQ terminals mean that the system can:

Have the humidifier on and dehumidifier on AQ, or dehumidifier on and humidifier on AQ
Support a 2-wire humidifier, dehumidifier or ventilation system

The Nest Thermostat E’s * or OB terminal lets you install a heat pump, a second stage of heating, or a second stage of cooling.

Learn more about the star terminal

Nest thermostat star connector

Systems that are incompatible with Nest thermostats

While most 24 V heating and cooling systems are compatible with Nest thermostats, there are some systems that aren’t compatible. You can quickly tell if you have one of these systems without having to use the Compatibility Checker or to look at your thermostat’s wiring.

If you have one of the system types below, it won’t work with a Nest thermostat.

Proprietary systems

If you find wires in your thermostat’s terminal that have non-standard labels (for instance 1,2,3, or A, B, C), your system is proprietary.
If your system only has 2 wires, but you have both heating and cooling, your system is likely proprietary.

Proprietary systems aren’t compatible with Google Nest thermostats. However, some proprietary systems provide an adapter you can use for it to be compatible with your Nest thermostat or you can have it rewired by a pro installer to be compatible.

Millivolt heaters

Millivolt systems are typically wall heaters or floor heaters and use electricity or natural gas. These systems use much less electricity than low voltage systems and can't deliver the right amount of power to Nest thermostats.

Picture of a floor furnace and wall-mounted furnace

High voltage systems

High voltage systems are usually electric baseboard heating systems or other radiant systems powered by electricity.
High voltage thermostats are often built into the wall and typically have 2 to 4 thick wires coming out of the thermostat. Wire nuts are often used to connect the thermostat to the system wires.
High voltage thermostats are usually labeled 110, 115, 120 or 240 VAC. Note: In some cases, it is possible to make a high voltage system Nest-compatible. Contact a local professional and have them install a step down transformer to 20 - 30 V.
High voltage thermostats should only be installed or uninstalled by a professional due to the high voltage that they carry.

high voltage text

high voltage wire nut

Solid fuel systems

Systems that use coal, wood chips, pellets, anthracite, or other biomass materials are typically incompatible with Nest thermostats.

Wired remote sensors

Remote sensor wires are typically used to give your thermostat outside weather data. These wires can’t be connected to Nest thermostats. But Nest thermostats don’t need wired sensors since they get weather information over Wi-Fi. Even if your system has sensor wires, it may be Nest-compatible.

Micro-controller based systems

Systems that use micro-controllers instead of relays are sometimes more sensitive to power sharing. If you have a micro-controller based system, your Nest thermostat may need a C wire or Nest Power Connector to be compatible with these systems.

Zone relay or control panels

Some systems have control panels or equipment interface modules that require a C wire to be compatible with Nest thermostat.

Incompatible system wiring

Too many stages of cooling or heating

Conventional systems: Nest Learning Thermostat (4th gen) can support up to 2 stages of cooling and up to 3 stages of heating.
Heat pump systems: Nest Learning Thermostat (4th gen) can support 4 stages of heating, consisting of 2 stages heat pump heating and 2 stages of alternate heating. Nest Learning Thermostat (4th gen) can support up to 2 stages of cooling.
The Nest Thermostat E is only compatible with one stage of heating, one stage of cooling, and an additional stage of either heating or cooling.

International systems

Some international systems, such as Buderus boilers, have dry contacts or other incompatible wiring. These systems may require relay panels in order to be installed with standard American or Canadian thermostat wiring.

Heat pumps with L wires

L wires are typically used to show system status, like emergency heat being on. Nest thermostats can work with systems that use Service Light (L) wires. While L wires can't be connected to the Nest thermostat, it doesn't need them. The Nest thermostat and Nest app shows you system status information without connecting L wires.

Forced hot water or steam systems

Dual fuel systems

A dual fuel heating and cooling system (also called a hybrid or packaged system) is a combination of a heat pump for primary heating and cooling, and a furnace (usually gas or oil) that provides a second and/or third stage of heating.

Nest thermostats are compatible with these systems and support up to 2 alternate heat sources.

You have a dual fuel system if you have a furnace inside your home, and a heat pump on the outside of your home. Heat pumps look similar to air conditioners, so check the label on your outdoor unit to make sure it’s a heat pump. If you’re still not sure which system you have, contact a local HVAC professional.

If you have a dual fuel system, you need to have a trained professional set up your thermostat. It’s important for a professional to assess the requirements for your specific dual fuel configuration since choosing incorrect options for a dual fuel system can result in damage to your system. Contact a local HVAC professional.