How to Install a Smart Thermostat : A Step-by-Step Guide

How to Install a Smart Thermostat

Installing a smart thermostat in your home is a great way to control your heating and cooling systems more effectively. A smart thermostat, when installed correctly, can help you save a lot of money on electricity.

If your AC is running on clean energy and operating at a high level of efficiency, you can even cut down further on your electricity bills. If you have been thinking about replacing your old thermostat with a new smart device, you may have some questions about installing it.

So, is it possible to install your own smart thermostat? Most homeowners typically enlist the services of a certified electrician to install their smart thermostats. However, if you are on a tight budget and are unable to afford the services of a qualified electrician, you will be pleased to learn that you can install the thermostat easily and conveniently by yourself. 

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Installing your thermostat yourself can not only help you significantly cut down on costs but also develop a better understanding of your home’s electrical connections. This will also make you better equipped to troubleshoot any malfunctions and performance issues that may arise in the future.

Installing your own smart thermostat does not come without considerations, however. This guide will walk you through the pre-installation, as well as the steps to install. Keep reading to be as prepared as possible to install your smart thermostat. 

Steps to Take Before Installing your New Smart Thermostat

This process might sound a bit daunting at first, but I assure you  it is not only possible to install a smart thermostat yourself but it might be more practical to do so. Some of these devices like Nests and Ecobees have been designed in such a way that you can install them without the help of a professional.

So if you have purchased these devices and you have got enough time for the project, it is prudent to do it on your own. This will cut on the initial cost you incur in order to have this expensive device in your home.

Before you embark on your DIY smart thermostat installation project, there are several things you need to do in order to ensure that the process is as smooth and error-free as possible. Here are some of the steps you need to take prior to the installation process

1. Check whether Your System is Low Voltage

Most smart thermostat devices are designed to be compatible with low voltage (24V) systems. Therefore, before you begin the process of installing your new smart thermostat, you have to confirm that your HVAC system is compatible.

A good clue to take note of when checking the compatibility of your HVAC system is if you already have a single thermostat in the house that regulates heat in the furnace (typically found in the basement or garage). The wires will probably be thin and multicolored.

It is also possible that your house might have an HVAC system that is incompatible with smart thermostats. For instance, if you have a thermostat and heater pair in every room of your home, then it is very likely that you have line voltage systems that are not compatible with most thermostats manufactured today.

Most thermostat manufacturers nowadays also provide compatibility checking tools that are simple to use. You can use these resources to determine whether your existing HVAC system can support a smart thermostat. In order to do so, simply pull out your existing thermostat from the wall and check the wiring.

You can then visit the website of your manufacturer to ascertain whether your existing electrical system is suited for smart thermostat devices.

2. Confirm whether you Have Enough Wires

Once you have evaluated your HVAC system’s compatibility, the next thing you need to do is check whether you have enough wires for your smart thermostat installation. When installing a smart thermostat, you will probably need a wire to wire to plug into the C-terminal in order to supply continuous power to the thermostat device.

To determine whether you have ample wires for your thermostat installation, you will need to check inside the furnace or in the wall behind your current thermostat.

Scan the area wiring carefully and identify any wires that are tucked in and not in use. If you don’t have enough wires you may need to purchase new wires or a dedicated adapter. 

3. Take Quality Photos of Your Existing Thermostat Wiring

Most people tend to overlook this step when preparing for a thermostat installation, but taking photos of existing wiring is actually very essential.

Doing this can help you to return your old thermostat to the position in case the installation process for your smart thermostat goes awry. This can also benefit you if you forget which wire needs to be connected to which area. 

4. Evaluate what will happen to the wall behind your current thermostat

In most cases, replacing a thermostat will not necessitate any additional repairs to the wall such as painting. This is especially true if your old thermostat is small and the new one you plan to install is larger.

However, in some instances, you may have to take in additional costs to repair the wall following a new thermostat installation. Some of the common problems you are likely to encounter when installing your new smart thermostat include damage to the wallpaper and mismatched paint.

You should, therefore, factor in any of these additional costs before beginning your smart thermostat installation project.

5. Factor in Weather Conditions before Replacing your Thermostat

As a rule of thumb, you should be cautious about pulling out your old thermostat if you anticipate a storm of the hurricane. Tearing your old thermostat off the wall during extreme weather can damage your electrical connection and pose a health risk. It is therefore advisable to wait it out until the weather is more stable.

Another reason to check the weather conditions is to ensure you do not need your thermostat running. You should do your thermostat installation when it will not cause the house to fluctuate the temperature too much.

6. Tools Required for a Smart Thermostat Installation

Once you have finished the preparation and assessment phase for your new smart thermostat installation, you are ready to begin setting up your device.

There are several tools you will need to conduct a DIY smart thermostat installation. These include: 

  • Screwdrivers
  • Screws
  • Masking tape
  • Level
  • Drywall repair sparkle
  • Paintbrush
  • Touch up paint
  • Smartphone
  • WiFi network password
  • Painter’s tape

Ensure that you have all the tools you need prior to beginning the thermostat installation process in order to make the project as smooth and hassle-free as possible. Screws will (almost always) come with the new smart thermostat, so ensure you have a screwdriver that will work with them and with the screws on your current thermostat.

How to Install the Smart Thermostat

With all your tools assembled and ready, you can proceed with the installation process for your new smart thermostat. Here are the steps you need to follow when installing a smart thermostat by yourself. 

1. Switch off your Power Supply

Whether you are highly experienced or a complete novice at electrical DIY projects, it is advisable that you switch off your power supply before beginning the installation process for your new thermostat.

This is the only way to ensure that the project is conducted in a safe manner. Failure to do so might greatly jeopardize your safety and make you susceptible to electrocution which is the last thing you want to happen when conducting any project that involves electricity.

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I would highly recommend installing your smart thermostat during the daytime so that you have enough natural light to work with. If you know your breaker system well, you may be able to just switch off power to the room where the thermostat is held. Just be safe and make sure you do this first.

2. Open Up Your Existing Thermostat

Once you have switched off your power supply and ensured there is no electrical current still passing through, the next thing you need to do is open up your old thermostat.

You will likely need a screwdriver to unscrew the thermostat and pop open its front cover. Depending on the thermostat you are using you might also be able to pull out the cover without requiring a screwdriver.

Make sure to have a good look, this is also where you should be taking pictures. Knowing exactly how it works will make the rest of the process smooth.

3. Label the Wires Correctly

After you have opened up the front cover of your old thermostat, you will need to label them correctly in order to keep them organized. Labeling the wires helps you keep track of the connections in order to avoid errors when installing the new smart thermostat.

Some devices such as the Nest thermostat come with stickers that you can use to label the different wires for easy organization. If your smart thermostat package does not have these stickers you can use other tools such as different colored masking tape to label them.

4. Remove your Old Thermostat from the Wall

Once you have properly labeled all the wires, the next thing you need to do is to pull your old thermostat off the wall. Use a screwdriver to unscrew the thermostat and then carefully remove it from the wall.

Ensure that none of the wires are damaged and no labels or stickers come off since you will need to use them as guides when installing your new device.

5. Place your New Smart Thermostat on the Wall to Level

Some modern devices such as Nest thermostats provide a level within the product which makes the process of setting up quite easy.

The level makes it easy to identify when the device is evenly placed on the wall so that you can make a mark on the precise spots where you need to drill. However, if your smart thermostat does not have an internal level, you need not worry.

You can use an external level very easy to mark the positions accurately prior to drilling and screwing the device onto the wall. 

6. Connect the Wires to Your New Thermostat

This is the point at which the labels you had made earlier comes in handy. You will need to match each wire’s label to the labels on your thermostat.

Make the connections between the wires and your new thermostat and then pop them into place to ensure they are firmly and solidly connected. Ensure that the little box in which the wires go is able to push down easily since that is how you will be able to tell the connection is secure and properly done.

7. Switch the Power back On

If you have installed the new thermostat correctly, it should light up a few moments after you switch the power back on. In case it fails to do so, then that should be an indicator that the wiring connections were not done properly.

Switch off the electricity again and examine the colored wires to determine whether they are all in the right spots and pushed down correctly.

Once your thermostat lights up, it will immediately begin prompting you through a guide on how to incorporate this new technology into your home.

8. Calibrate your Heat and AC Using Your Smartphone

Once your smart device is properly set up and operational, you can connect it with your home’s WiFi network to begin controlling and monitoring it using your mobile phone. This smart technology allows you to operate and calibrate your heat remotely as long as there is a WiFi connection. 

Buying the Best Smart Thermostat

Having the right smart thermostat is absolutely essential when it comes to maintaining your room temperature. A good device can significantly improve your indoor comfort, make your life a lot easier, and allow you to save money. 

With plenty of devices in the market, however, choosing the best smart thermostat might seem like a very daunting task. However, this does not have to be the case. As long as you know exactly what you are aiming for, you can certainly find a great device that provides you with the best performance features and value for your dollars. 

So, in this section, we are going to go over some of the factors that you need to consider when purchasing a smart thermostat. This guide will explore some of the main features of smart thermostats in order to help you make an informed choice on the right product to go for. 

Here are some of the things you need to keep in mind when shopping around for a new smart thermostat. Also check out my review of the smart thermostat I recommend.

Thermostat Power

If you are considering making a purchase on the new smart thermostat for your home, it is absolutely vital that you choose a device that is compatible with your home’s power supply.

Smart thermostats generally have varied power supply needs. While most devices manufactured today require 24V, there are some which operate at voltages as high as 110V and 240V. 

High voltage smart thermostats are generally great for electric baseboard systems. Low voltage devices, on the other hand, will work best with heat pumps, air conditioners, and boilers. There are also millivolt thermostats that require very little power to operate. These ones are typically best suited for space heating. 

Before deciding which thermostat to buy therefore, you should think carefully and what functions you intend to use it for and whether your electricity supply is sufficient to operate it. Doing so will enable you to get maximum performance from your smart device.

WiFi Smart vs Non-Wifi Thermostats

WiFi thermostats generally offer you more control over your device since you can set and control temperatures using your Smartphone, tablet or computer. These thermostats are however more expensive than non-wifi thermostats so you should be prepared to pay extra money if you opt for one.

Keep in mind that WiFi Smart thermostats rely on stable WiFi connections which essentially mean that you will not be able to control your device during downtime unless you do so by hand.

If you don’t mind not having the remote capabilities that WiFi Smart thermostats offer, then you are better off choosing a non-WiFi device which will also save you a lot of money in up-front costs.

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Programmable vs Non-Programmable Thermostats 

Programmable smart thermostats are very convenient since they allow you to program the device separately for weekdays and weekends.

Generally, these thermostats allow you to choose between four temperature settings and change them automatically during the course of the day. Programmable thermostats tend to be more expensive than non-programmable ones. But that is probably a small price to pay considering the extra comfort and convenience they offer.


Many smart thermostats manufactured today are designed with a backlit display which makes it a lot easier to read and control the thermostat any time of the day or night.

There are also those which come equipped with intuitive controls so that you can key in what you require. These features provide more comfort ad make operating the device hassle-free.

Geofencing vs Non-Geofencing Capabilities

There are smart thermostats that are designed to automatically adjust the temperature when you are not around. They do this by tracking your movement through your Smartphone. This feature is very useful because it helps you save money by cutting down on energy usage.

For instance, you can remotely switch off the device while you are away and turn it on when you are just about to get back home. This is done by creating a boundary in your neighborhood within the App. This is what is called Geofencing

Apart from switching off and on, the App also allows you to set a perimeter such that the device adjusts the temperature accordingly when you leave the house or come back.

Even more interesting is the fact that some of the ultra-modern devices are able to learn your routines and create temperature schedules, without the need for manual programming. 

Method of Installation

Many smart thermostats usually come with a manual on how to install the device. If you intend on installing the thermostat yourself then this is a very useful addition to have. But even if your smart device does not come with a manual, there are plenty of resources on the internet where you can find guides on how to install a smart thermostat.

Before purchasing your new smart thermostat, make sure there are enough resources out there on the one that you want. New brands and thermostats owned by particular companies may not be as user-friendly for installation.

Types of Thermostats: How Different Thermostats Work

Based on the technology used, we can classify Thermostats into two broad categories; Traditional and modern thermostats. Modern technology is just but an improved traditional one. This improved knowledge makes vital differences.

Traditional thermostats

In order to understand how a smart thermostat works, let us first consider the mechanism of a traditional thermostat.

In the old non-digital devices you usually set the temperature using a dial. Inside the thermostat, there is a thermometer connected to a metal strip that completes an electric circuit that switches on your boiler.

As the air in your home gets heated up, the metal strip is heated until it reaches the temperature you have set. When this happens the circuit breaks since the metal strip has expanded and breaks away from its connectors causing the boiler to turn off.

When the house cools, the strip does so too and eventually connects back into place and complete the circuit. This causes the boiler to turn on again.

Modern thermostats

Programmable and smart thermostats use a similar but digitized mechanism to accomplish the same function. Smart thermostats are improved versions of programmable and they work more efficiently. 

The circuit in a smart device is controlled by a thermometer that switches off the boiler automatically when the desired temperature is attained.

Some smart thermostats can be connected both to your boiler, through your existing thermostat wired connection, and your home Wi-Fi network.

What this essentially means is that your old boiler can be part of the smart home, without you having to buy a new boiler with Wi-Fi capabilities. However, your boiler needs to be compatible with your thermostat. So, you need to check properly when you are looking for the right smart thermostat to buy. 

When using a smart thermostat you will also need to download a companion app which you will use to change your thermostat settings within seconds from wherever you are. Here is how you would go about changing the temperature settings of your smart thermostat on your phone. 

  • Open the companion smartphone app and key in your desired temperature. 
  • The new setting is sent to your home through the internet. 
  •  Your Wi-Fi router then transmits the instruction to your smart thermostat which readjusts the temperature and sends a signal to your boiler to turn on or off

Some smart thermostats come with a variety of features that can help you to cut down on your electricity bills significantly. These devices are able to learn your behavior and intuitively regulate the temperature depending on whether you are home or not.

In case you go on holiday and are worried you forgot to turn off the heating system, the app will alert you so that you can set the thermostat as desired. This offers you greater freedom, convenience, and control over your smart device. 

If you are replacing your old thermostat with a new smart device, you need to take the appropriate security precautions to ensure the operation and performance of your thermostat is not compromised.

One of the ways to do so, for instance, is choosing a secure password which should be private. Otherwise, someone might take control of your thermostat and interfere with your settings. 

Such irresponsible people might turn up your heating system when you’re away and cause you to accrue a very high electric bill. It is therefore advisable that you take the necessary action precautions to avoid such a scenario. 

Final Thoughts on How to DIY Install a Smart Thermostat

If you are planning on replacing your old thermostat with a new smart device, there are definitely a lot of things to factor. Nevertheless, having a smart thermostat installed in your house can greatly improve your comfort and make your life much easier. 

While smart thermostats are more expensive compared to old digital ones, you can offset the cost of installation by conducting it yourself.

You do not have to be an experienced electrician to install a smart thermostat. The process is fairly simple and straightforward. As long as you have the right tools and information at hand, you can install any kind of thermostat in less than an hour. 

After reading this review, you certainly have a fairly good grasp on how to install and set up a smart thermostat. So why not go ahead and DIY install your new shiny device? You will be very surprised by how much money you can save.