Nest Support

Questions about Nest Learning Thermostat or Nest Protect: Smoke + CO alarm? We've got answers, videos, and plenty of resources to help you out.

What is a multistage system?

Multistage heating and cooling systems help households use less energy. The Nest Learning Thermostat is compatible with up to three stages of conventional heating and two stages of cooling.

What is a multistage system?
Multistage systems use multiple levels of heating or cooling to save energy. Like a dimmer on a light switch, they adjust the level of heating or cooling to the temperature you set. These efficient systems use the lowest level of heating or cooling needed and only use higher levels for those really freezing or scorching days. Using lower levels of heating or cooling is more efficient because the system doesn’t need to turn on and off as often to maintain a constant temperature.

Most older systems are single-stage, on-or-off systems with only one level of heating or cooling.

Does the Nest Thermostat support multistage systems?
The 2nd generation Nest Learning Thermostat supports up to three stages of heating and two stages of cooling for conventional systems, and two stages of heating and cooling with auxiliary heat for heat pumps.

The 1st generation Nest Learning Thermostat supported two stages of heating and one stage of cooling for conventional systems, and heat pumps with auxiliary heat.

How can I tell if I have a multistage system?
Most multistage systems can be recognized by the wires attached to the thermostat. Conventional single stage systems will only have one wire for heating (W1) and one wire for cooling (Y1). Single stage heat pumps only have Y1 for both heating and cooling.

Multistage systems will have more than one heating or cooling wire. For example, three stage conventional heat uses wires W1, W2, and W3; Two stage cooling or heat pumps use Y1 and Y2. Some heat pumps also have auxiliary heat, an additional stage of heating that is only used when the heat pump compressor can’t keep up with cold weather conditions.

What’s the difference between multistage systems and zoned systems?
Multistage systems are different from zoned systems. Zoning has nothing to do with your system or connected wires. Instead, zoning is a way to heat or cool different areas (“zones”) of the home separately, either using separate systems or using dampers in the ductwork to guide hot air to each zone.