The use of smart thermostats in the UK has become increasingly popular as they’ve dropped in price over the years. However, many people that aren’t familiar with them may be wondering how does a smart thermostat work?
To explain how they work, we have used the Hive Acting Heating system as an example because it’s the one that we installed in our very own home. We installed this particular thermostat because it’s one of the best smart thermostats on the market and it ticks all the boxes in terms of the stylish design as well as usability when using the smartphone application.
How Does It Work?
Understanding the exact process of a smart thermostat will help you make the correct buying decision for your home. Below is a simplified diagram of the connections involved with installing the device to your boiler.

The Hub
To form the remote connection, the thermostat needs to be connected to the internet. This is achieved via the hub, which connects to the router via an Ethernet cable.
However, if you already use an existing hub for other devices such as a smart plug, you won’t need to purchase another one. This is because most hubs are designed to handle multiple devices simultaneously.
Receiver To Boiler Connection
After setting up the internet connection, the next step is to connect the receiver which communicates between the remote connection and the boiler. Depending upon your existing setup will determine the difficulty of the installation.
If you have previously used programmable thermostats with your boiler, you won’t need to set up the external connections again (labelled in red below). These connections are the only part of the installation that may require a professional to install.

If they are already installed, you can simply plug the receiver into the socket (labelled in blue above). Within this particular installation, there are two receivers because one controls the radiators and the other is used for our underfloor heating installation.
Receiver To Thermostat
The receivers are normally the most time-consuming part of installing a smart thermostat. Once set up, you can then begin to connect the thermostat to the receiver, which can be achieved by following the instructions on the smartphone application.
It’s important to note that some receivers may perform firmware updates and refuse to connect until it’s complete. To confirm this, check to see whether the receiver is flashing or outputting a light because this can be used for diagnostics.
After the connection is successful, you’ll want to test that your actions are carried out by the boiler. We advise that you perform basic functions such as manual overrides and scheduling the boiler to turn on at certain times of the day.
Other Smart Devices
The majority of thermostats also connect with smart devices to further enhance their functionality. Some of these devices include Amazon Alexa, Google Home Assistant, Apple HomeKit, IFTT and many more. The additional functionality can include voice commands such as “Alexa, turn the radiators to 21 degrees for 3 hours” and so much more.
How Easy Are They To Use?
Many people that aren’t “tech-savvy” may be worried about the smart thermostat’s ease of use. However, the majority of devices are designed with usability in mind and feature interfaces that only require one or two actions to control your boiler. They can also be used with smartphone applications that are just as easy to use and very desirable.
As you can see in the video that we posted on our YouTube channel below, we were able to adjust our boiler by using Hive’s smartphone application, which then updated the temperature on the receiver.
It’s worth pointing out that as well as adjusting our boiler, we can also easily adjust other smart heating components such as our smart radiator valves from the smartphone application.
Are They Worth It?
There is no denying the fact that a smart thermometer does come with a premium price tag. However, they provide extra convenience and in the long run, they will help you become more energy efficient and save you money.
We highly advise that you buy from a reputable brand in the UK and if possible, think long term. For example, if you plan to add other Hive smart devices to your home, choosing the Hive kit would be the best option.
If you require further information regarding how a smart thermostat works, feel free to get in touch and we will try to provide our assistance where possible.