No it will not:
Compatible with most 24V heating and cooling systems.
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 connector that have non-standard labels (for instance 1,2,3, or A, B, C), your system is proprietary.
If your system only has two 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 can be rewired by a pro installer to be compatible.
Proprietary wires
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 two to four 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 pro 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.
Solid fuel system
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 still be Nest-compatible.
Some 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 to be compatible with these systems.
Systems that can’t deliver enough power
Some systems can’t deliver enough power (at least 20 volts) over the existing system wires, so a Nest thermostat’s battery may slowly drain and eventually cause the thermostat to turn off. These systems are sometimes called high impedance systems. You may be able to install a C-wire to make your system compatible with a Nest thermostat. Contact a local pro.
Some system hardware such as gas valves and zone or relay panels require a C-wire to work with Nest thermostats. If you would like to find out more information about installing a C-wire, contact a local pro.
Gas valves
Some gas valves on systems vibrate or buzz when a Nest thermostat is installed. This can usually be fixed by connecting a C-wire.
Zone relay or control panels
Some systems have control panels or equipment interface modules that require a C-wire to be compatible with Nest thermostats. Below is a list of some known panels that require a C-wire. This list is not meant to be comprehensive, so your system may be incompatible even if it isn’t listed here.
Beutler ZTE2S
Bryant 548F036
Carrier HK42FZ011
Honeywell AQ25110B
Honeywell EMM-3
Honeywell HZ221
Honeywell HZ311
Honeywell HZ322
Honeywell HZ462
Honeywell Trol A Temp MABS EZ
Honeywell TZ-4
Lennox LZP-2
Nordyne 624631-A
Nordyne 903915A
Villara ZTE2S
Waterfurnace ATV045A 110CIT
White-Rogers 36C03-300
ZoneX DigiTract 4
Ztech ZTE2S
Incompatible system wiring
Too many stages of cooling or heating
Nest Learning Thermostats are only compatible with systems that have one or two 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 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, they don’t need them. The Nest thermostat and Nest app will show you system status information without connecting L wires.
Answered by: Mark
Date published: 2021-01-10
