how to install a thermostat

How To Install A Thermostat Without An Electrician

Ian Mutuli
Updated on
Ian Mutuli

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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Programmable thermostats are increasing in popularity day by day thanks to the numerous benefits they offer. This handy home addition allows you to customize and regulate the heating and cooling system of your home. In turn, this saves you energy utility costs that would be high otherwise.

A smart or programmable thermostat automatically adjusts your home's temperature based on the occupancy and the time of day. For example, during the cooling season, the house temperature can rise if no one is at home and start cooling based on the time the occupants return home. This ensures that your home is not being heated or cooled down when no one is there.

If you're still not sure if it is time to switch out your old thermostat for a smart programmable model, we will look at some benefits of having a smart thermostat. However, this article will focus on how to install a thermostat, like what tools do you need, how long it will take and so on.

Why Should You Have A Programmable Thermostat?

A programmable or smart thermostat:

  • Automatically adjusts your home's heating and cooling system. This ensures that you don't have to get up and adjust the settings. For settings like turning on and off, you need to program beforehand when you would like these times to be.
  • Controls home temperature, making it more effective. Regulating your home temperature based on the occupancy helps you save energy and money that would have been used to run the HVAC system in an empty house.
  • Improves the lifespan and efficiency of your HVAC. By programming your HVAC into the smart thermostat, you limit its running time, making it more efficient while saving on costs. In addition, if you were planning on switching out the system, you can extend its lifespan this way.

What Do You Need to Know Before Installing A Programmable/Smart Thermostat?

  1. Ensure that the smart thermostat is compatible with your heating and cooling system. If you are unsure, it is advisable to call your heating and cooling contractor or utility provider.
  2. Inspect the existing thermostat. By checking the wires running from the furnace to the thermostat, you can determine if the current setup will work well with the new smart thermostat. If not, you may need to buy a new wire. In addition, if you are installing a non-programmable model, this process helps familiarize yourself with the thermostat wiring.
  3. You need to ensure that the new thermostat has a big enough faceplate to cover the hole left by the existing thermostat. To do this, measure the hole and compare the measurement with the new thermostat.
  4. It is essential to also check the new thermostat's compatibility with other systems, especially if you have a home security system in place. The two systems need to connect to ensure seamless use and communication. The same is with a voice assistant.
  5. Lastly, check the manufacturer's recommendation on installation and warranty. Will installing the thermostat on your own jeopardize the warranties? Again, this is vital information to know beforehand.

Tools Needed

  • Screwdriver
  • Drill
  • Masking tape
  • Marker pen
  • Wall anchor

How To Install A Thermostat

Follow this step-by-step guide to remove your old thermostat and replace it with a new smart thermostat. It is easy and concise.

Step 1: Remove the Old Thermostat

Before removing the old thermostat, you need to turn off the heating and cooling system at the circuit breaker box or the main fuse. Since the old thermostat is turned off, you can proceed to take off the lid. Some thermostats will need you to be unscrewed to remove the faceplate, while others will simply pop off with a bit of pressure. Once the lid is off, leave the wall and the wires connected as they are.

Step 2: Label the Wires

This stage involves labeling the wires from the existing thermostat installation. Take a small masking tape and attach it to each wire, labeling the indicated letter where the wire attaches to the old thermostat. In addition, do not pay much attention to the wire color. This is because it is not always that the letter corresponds with the wire color.

Step 3: Take A Picture for Reference

Taking a picture of the existing thermostat wiring gives you a visual reference for the new thermostat installation.

Step 4: Disconnect the Wires

Using a screwdriver, disconnect the wires to remove the wall plate. This next step is important and will save you unnecessary frustration and aggravation. Next, wrap the existing wires with a clothespin, small screwdriver or tape them to the wall. This ensures that the wires do not retreat to the wall cavity when separated from the old thermostat.

Step 5: Remove Existing Wall Anchors

This step is important if the new thermostat has a different size and shape from the previous one. However, if they're both of equal shape and size, skip this step.

Step 6: Install the New Backplate

If you had removed the old wall anchors, use a level to mark the new drilling holes and then proceed to drill. However, before installing the thermostat mount, it is necessary to confirm the connection. If you can only see two wires connecting to your existing thermostat, the programmable thermostat is likely battery-powered. However, a direct-wired programmable thermostat will have more than two wires.

Having confirmed the wiring, it's time to install the new thermostat's backplate. At this stage, it is important to go over the manufacturer's instructions again. First, fasten the wall plate to the wall using fasteners and then secure the wires, so they do not fall back.

Step 7: Connect the Wires

Ensure to follow the instructions to the letter when connecting wires. Ideally, you will be matching the letters on the labeled wires to the letters on the new thermostat. Once you have inserted the wires into their corresponding terminals, ensure that you tighten the screw terminals. In addition, ensure that you have a C-wire for a new programmable thermostat using WiFi. However, if you have a non-programmable thermostat, this is the part of the thermostat installation where you need to connect the batteries.

Step 8: Install the Faceplate

Having completed the thermostat wiring, it is now time to install the faceplate. Again, ensure to follow instructions as per the given manual.

Step 9: Restore Power

Now turn the circuit breaker on to restore power in your home. This will also restore power to the air conditioning unit and furnace. At this point, set up the new thermostat settings according to your schedule. Most smart thermostats will have an app, so be sure to download it and regulate heating and cooling in your home from anywhere.

Frequently Asked Questions

1. Can I install a thermostat myself?

Yes. You can install a new thermostat yourself in only a few steps. The main requirement is to follow the manufacturer's instructions and this step-by-step guide. In addition, unless there are other problems related to your existing HVAC system, installing programmable and smart thermostats should be a breeze.

2. Do you need an electrician to install a thermostat?

You do not need an electrician for a new thermostat installation. Programmable thermostats have been designed in a way that you can easily install them. In addition, this saves you extra money that would have been spent paying an electrician.

3. Is it easy to install a new thermostat?

Our step-by-step guide is proof of how easy it is to install a new programmable thermostat. This guide, along with the manufacturer's instructions, should be enough to switch out your old thermostat for a new smart model. In addition, this whole process will take you an hour or less.

4. Can I replace my thermostat with any thermostat?

When purchasing a smart replacement thermostat, it is recommended to find one that is compatible with your current system. However, you will find that replacement thermostats will be compatible with most systems unless you have a unique system.

5. How do you wire a new thermostat?

When wiring a new thermostat, the key is to ensure that the wires are connected to their corresponding letters. This is because sometimes, the wire colors do not correspond with the letters. In addition, you need to ensure that the screw terminals are tightly closed.


A smart or programmable thermostat is an excellent addition to any home for temperature regulation and control. A programmable thermostat will automatically adjust the heat and coolness of your home at a scheduled time. This helps save utility bills since your home will be in energy-saving mode when no one is in. In addition, since thermostat installation is relatively easy, you save money by skipping the costly decision of calling an electrician and doing it yourself.

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Ian Mutuli

About the author

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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