Technology
How does a thermostat work?
A thermostat works by sensing the room's temperature and switching heating or cooling on or off to keep it near a set target. It is a feedback loop: when the room drifts from the setpoint, the thermostat turns the system on until the temperature returns.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how a thermostat works.
Step by step
- 1It compares the measured temperature to your chosen setpoint.
- 2If the room is too cold (or too hot), it switches the heating (or cooling) on.
- 3When the target is reached, it switches the system off — a continuous feedback loop.
- 4Older units used a bimetallic strip that bends with temperature to flip a switch; modern ones use electronic sensors.
- 5Smart thermostats add schedules and learning to anticipate your needs and save energy.
Frequently asked questions
- What is a setpoint?
- The target temperature you choose. The thermostat works to keep the room close to it by switching the system on and off.
- How did old thermostats sense temperature?
- Many used a bimetallic strip — two metals that expand at different rates — which bends as it heats or cools and trips a switch.
- How do smart thermostats save energy?
- They learn your routines and adjust automatically, avoiding heating or cooling an empty home and trimming waste.