If you re not sure which kind of system you have you can quickly pop off your current thermostat and take a look at the wiring.
Using nest with high voltage.
It s also overly complex and dangerous.
Google nest thermostats are designed to work with most 24v systems even older systems.
However some systems that are high voltage use a higher current sometimes as high as 16a or higher for example electric radiators or electric underfloor systems.
Thermostats are designed to handle either low current or high current.
Do not skip it s important to install the heat link before the nest thermostat otherwise high voltage current will irreparably damage the nest thermostat 12 12v power to thermostat call for heat common satisfied optional 230v ac live and neutral input power thermostat.
The fan coil unit is new high voltage and has a motor with 3 speed settings.
Install nest thermostat with line high voltage i have made a step by step instructional guide with pictures over at nest s community page on how to install and use a nest thermostat when you have line voltage and baseboard electric heat.
This is a cooling only fan coil system.
Installing a compatible smart thermostat is quick and easy.
The nest will work with any low voltage system but it won t work with high voltage systems also known as line voltage at all.
They work with all common fuel types including natural gas oil and electricity.
Nest and ecobee thermostats were made to control low voltage 24v heating systems and electric baseboard heating is high or line voltage 120v or 240v.
It learns your habits and is controllable using smartphone applications when situations arise and you need to change the settings.
Simply put they are not compatible.
Install nest thermostat with line high voltage i am new to reddit so i put my step by step instructional guide with pictures on how to install a nest thermostat when you have line voltage and baseboard electric heat in home improvement instead of directly into the nest subreddit.
The nest thermostat only supports low current systems since they are by far the most common.
Today s best known smart thermostats from manufacturers like ecobee nest and honeywell are desig.