What Are Thermostats and How Do They Work? (This Will SURPRISE You!)

Known as the handy little helpers, thermostats control your home’s cooling and heating systems. They also help manage other systems, such as ovens, fire sprinklers, and engines.

Not only are thermostats convenient, but they’re great energy-savers as well. So, in order to get to know more about these devices, we decided to tackle the question: how does a thermostat work, and what are they exactly?


Let’s dive in.

What Are Thermostats?

The word ‘thermostat’ comes from the Greek thermos, which means ‘hot’ and statos, meaning ‘standing in place’ or ‘stationary.’ Basically, a thermostat is a device that keeps an eye on the temperature in any given setting.

The whole point of having a thermostat is to regulate the flow of heat transfer fluid when needed. As a result, by holding back this fluid or pushing more through, a thermostat helps maintain the correct temperature.

How Does a Thermostat Work?

Thermostats have a pretty basic setup when it comes to how they operate. In general, these devices are available as either line-voltage or low-voltage.

Check out how each one works.

Line-Voltage Thermostat

As the name suggests, line-voltage thermostats operate using a single heating system. Usually, you can find them in conjunction with baseboards, wall heaters, and radiator systems.

These devices work via a connection that flows from the thermostat into the heater. They only have one job: control the amount of current running from the wires to the heating unit.

Low-Voltage Thermostat

Low-voltage thermostats are more efficient in their ability to keep tabs on airflow. They also provide more options and better accuracy of temperatures and airflow.

The difference between this type and line-voltage thermostats is that the latter is responsible for only one heating/cooling unit. However, a low-voltage thermostat helps oversee a home’s entire HVAC system.

These convenient devices work in the background to adjust your home temperature via control signals. When a low-voltage thermostat senses that the temperature in your home is lower than the preset input, it signals to the HVAC system, which will burn fuel to heat your home accordingly.

Types of Wall-Control Thermostats

There are two main types of wall-control devices: mechanical and digital. Both feature a way to set your thermostat to your preferred temperature. Thus, when ambient temperatures drop or increase by about five degrees or more, the thermostat kicks into action.

Say you set the thermostat to 70℉. Then, temperatures in your home get colder and reach 60℉. This is when the thermostat will power on, signaling the heating unit to warm up the air. When temperatures finally hit 70℉, the thermostat shuts down the heater to avoid loss of energy.

Mechanical Thermostats

A mechanical thermostat is equipped to sense the temperature of its surroundings, thanks to the two bits of metal found inside. Known as the ‘bimetallic strip,’ these two metals are designed to contract and expand according to the surrounding temperatures.

As a result, it makes contact and breaks off the connection with the electrical power supply. This primarily depends on the difference between the set temperature and the room’s actual temperature.

We should mention that mechanical thermostats aren’t as accurate as their digital counterparts. Sometimes, temperatures can vary from the target setpoint to a whopping five degrees.

Yet, their upside is that they’re more affordable. Plus, they’re easier to manage with the help of the user-friendly on/off switch and temperature dials.

Digital Thermostats

Digital thermostats are ‘closed loop devices.’ In other words, they’re able to automatically regulate a certain process, which is fixing the temperature without any manual input or human interaction.

They’re designed with internal components that provide a highly accurate quick-response reaction to the interior temperature. One of these components is an electronic sensor that reads the room’s current temperature. Subsequently, it’ll work to adjust and fine-tune the heating or cooling accordingly until temperatures reach their target setting.

The best part is that they come with both temperature and time settings. This means that you can adjust different temperatures for different times of the day.

For example, you can set the thermostat to turn off the heat when you’re at work to save energy and cut back on utility bills. Then, set it to turn on and start warming, or cooling down, the house before you get home.

Just remember to take into account that it takes several minutes to warm up or cool down. So, give it anywhere between 45 and 60 minutes to kick into gear, and adjust the temperature to your preferred set point.

One drawback is that they can be more expensive than mechanical ones. Plus, they require more effort to program, which can be a hassle for some people.

Best Place for a Thermostat

When deciding on the best location of a thermostat in a room or building, consider these options:

  • Thermostats should be placed anywhere between 48 and 60 inches above floor level
  • Keep them away from a room’s heating or cooling device, radiator, or vent
  • Avoid placing thermostats near office equipment
  • Set up thermostats in the area that gets the least draft and direct sunlight
  • Avoid setting up the thermostat near the controlled source, or it’ll short cycle

Common Thermostat Applications

You can find a thermostat anywhere that needs a central control unit for both cooling and heating. This includes any setting that requires controlling ambient airflow to inspect coolants in a vehicle’s internal combustion engine.

In open spaces with unrestricted airflow, like a hallway or open reception, it’s best to use a single zone system. This is where all nearby areas are controlled by one system, providing there are no doors, walls, or other obstacles that can get in the way of the thermostat doing its job.

If there are such obstacles, it’s best to use a multiple zoned system. It’s an efficient way to save energy by regulating the temperature in individual spaces accordingly. For example, if there are unused rooms, you can turn off the cooling and heating options altogether.

You can also find thermostats in the following systems:

Wrap Up

Knowing what a thermostat is and how it works gives you a better understanding of how to use it to its full potential. More importantly, it allows you to save energy and cut back on utility bills. So, you get to help save the environment and pay less each month—it’s a win-win!