What does thermostat do

HVACUpdated March 2026

The answer to 'what does thermostat do' is a thermostat is a device that controls the temperature in a home or building. It monitors the current temperature and turns the heating or cooling system on and off as needed to maintain the desired temperature set by the homeowner.

Thermostats are an essential component of HVAC (heating, ventilation, and air conditioning) systems. They allow homeowners to easily adjust and program the temperature to their comfort level and preferences. This helps optimize energy usage and saves money on utility bills.

Sources

ENERGY STAR— authority

International Association of Certified Home Inspectors— authority

U.S. Department of Energy— authority

Frequently Asked Questions

How does a thermostat work?

A thermostat contains a temperature sensor that measures the current temperature in the room or area. It compares this to the desired temperature set by the homeowner and turns the HVAC system on or off accordingly to maintain the target temperature.

What types of thermostats are available?

There are several types of thermostats, including mechanical, digital, programmable, and smart thermostats. Each offers different features and capabilities to suit a homeowner's needs and preferences.

When should I replace my thermostat?

You may need to replace your thermostat if it is old, malfunctioning, or not accurately controlling the temperature. Signs it's time for a replacement include erratic temperature readings, the HVAC system not responding, or if you want to upgrade to a more energy-efficient model.

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