Does the Nest Learning Thermostat work with zoned systems?
The Nest Learning Thermostat is compatible with zoned systems, including zoned systems with dampers. However, there are some zoned systems that require a common wire to work with the Nest Thermostat.
If you have more than one thermostat in your home, you have a zoned system. In zoned systems, each thermostat controls heating and cooling independently in order to heat or cool different zones of the house. Thermostats in zoned systems can control the same heating and cooling system or each thermostat control its own system.
When multiple thermostats control one system, the house is divided into zones using dampers in the ductwork throughout the house. When one zone needs heating, the damper for the ductwork in that zone opens, guiding the hot air to that zone. Zoning with dampers is usually coordinated using zone relay panels. Some zone relay panels don't allow your Nest Thermostat to charge sufficiently off of the heating and cooling system wires. If this is the case, the Nest Thermostat will need a common wire to provide power. Otherwise, the Nest Thermostat is fully compatible with zoned systems.
How is a zoned system different than a multistage system?
Where a zoned system will have different thermostats that control the heating and cooling for different parts of the same location, a multistage system is one zone where there is more than one level of heating or cooling. The allows households to save energy by only using the lowest level needed.
A multistage system will have multiple heating wires (such as W2 or W3) or cooling wires (Y2 or Y3). The Nest Thermostat is compatible with up to three stage conventional heating (systems with W1, W2, & W3) and two stage conventional cooling (systems with Y1 or Y2).