How to Install a Thermostat the Right Way?


A thermostat is one of the most important smart home devices for any home. The significance of using this device is such that many people are willing to go to the market and buy the best thermostat for their home. However, using this device requires caution as it’s what makes the home cold or warm.

Not many people know how to install it. Even Lawrence Berkeley National Lab conducted a study where they found that almost 90% of the U.S. people rarely install or program it on their own. The reason for this is they are not sure about how to install the device.

In this article, we are going to explain how you can install it. We would even enlighten you about the wiring and changing process of a thermostat. So, stay with us until the end and become a DIY owner of a thermostat.

How to install a thermostat?

Before installing a thermostat, you should read the manufacturer’s instructions because it will give you heads up about what you have to do. Now, let’s begin the installation process.

Step 1. Switch off the power

Firstly, you have to turn off the power supply to the furnace and air conditioner. To do that you should cut the power at the breaker box. You can even do it by removing the fuses at the service panel.

Step 2. Remove the old thermostat

In the second step, you should remove the old thermostat cover while unscrewing the old mounting plate. At this stage, you don’t have to disconnect the wires. Read the labels from the thermostat to make sure the wires are fully labeled. After that, you can start disconnecting the wires from screw terminals. You will find it helpful if you wrap the wires on the pencil. It will keep them from falling haphazardly.

Step 3: Start installing the new thermostat

Now, you can bring in your new thermostat and start installing it by threading the wires via the thermostat’s base. You should make sure the base is in a level position with the wall. For your convenience, you can mark the holes with a pencil.

Afterward, you can start drilling new holes, probably a 3/16 inch hole at the base of the thermostat. At this moment, you will lock the base into the place where you are going to install the device. In that case, you should start bolting the mounting screws into the wall.

Step 4: Wire the thermostat

Before wiring your thermostat, you must take a look at the instructions from the manufacturer. Now, start this step by mounting the device onto the plate. You can use a wire stripper for removing the plastic sheathing, which can be around 1/4 inch.

Now, you have to connect the wires to the terminals. You should make sure the letters on the thermostat matches with the masking tape labels. Remember that the wire should be wrapped under the screw head. You can tighten the screws by turning the head clockwise.

Step 5: Switch on the thermostat

This is the last where you will turn on the device and start programming it using the information manufacturer’s guide. This manufacturer’s guide should include the essential programming information.

How to reset a thermostat?

You might want to reset your thermostat because your temperature preferences can vary at times. With that in mind, if you know how to reset a thermostat, you can keep house’s temperature at an optimum level. So, we have taken a Honeywell thermostat’s resetting process as an example to explain the entire process:

  • At first, you should begin the process by switching off the thermostat.
  • Secondly, you have to insert a coin into the slot of the battery door. And then you have to push it to open. After that, you can remove the batteries.
  • Now, you should insert the batteries to a backward position to ensure the negative poles are lined up correctly with the positive terminal. And, you have to leave the batteries in that position for a minimum of five seconds.
  • Next, you will have to remove the batteries and then you will correctly flip them to close the battery door. If you see that the display is turned on, you have reset the thermostat on your own.

How to wire a thermostat?


If you own a wireless thermostat, then you don’t have to worry about wiring the device. But, in case, if the thermostat is a traditional one with a wire, you should know the wiring process. Again, we have taken a smart Honeywell thermostat for demonstrating the process. The exact model of this device is – Honeywell CT87N. So, let’s start learning the process:

  1. First of all, you should switch off the circuit breakers to make sure the power is off. Now, you have to remove the front cover of the device. Then you should position the thermostat, which would allow any local waste regulations for mercury (in case there is a mercury warning).
  2. In the next phase, you have to mark the wires with small pieces of masking tape. You should remember the marking must match with that of the terminal where it is attached to the base plate. You should also ignore the color of the wire while marking them by the letters that are stamped on the old thermostat’s wall plate. Now, you can start disconnecting the wires patiently.
  3. At this stage, you can now remove the base plate and bend the wires from the old thermostat, which are placed over the gap in the wall.
  4. Next, you should start threading the wires via the rectangular. And you can do this task by opening the base of the device. If you wish to position the unit correctly, you can use a level. If not, you can just align the device to the wall. From the sides of the base plate, you should mark the positions of both screw mounting holes. Now, you can remove the old thermostat, but you should make sure the wires remain intact.
  5. In the next step, you have to drill at the points that you marked before. You should use a hammer to tap into every hole. In case, you are using a cover plate; you should pull all wires through it. After that, you have to do the same thing through the rectangular opening, which lies at the bottom of the device.
  6. Using the anchors, you should line up the mounting holes and screw them firmly to fit in with the anchor. Afterward, you have to match the marked letters on the tape labels with that of the letters embossed on either left or right side of the terminal block.
  7. Now, you should unscrew the terminal screw to insert the visible end of the wire to the terminal slot. Then, tighten the screw and tug on the wire. You should make sure the wire doesn’t come out of the slot.
  8. You are at the last stage of wiring your thermostat where you need to set the fan switch in the center of the base to ‘E’ (for an electric heating system). Next, you have to move the two cycle rate switches by the settings of the device. Finally, you should align the tabs with lugs in the base and put the cover into place.
  9. This step is the last step where you need to restore the power settings. You should just set the dial and configure your heating or cooling preferences.

How to replace a thermostat?

If you wish to change a thermostat, you can do it by reading the manual guide.

Besides, if you read the below steps carefully, you can smoothly change a thermostat.

  1. In the beginning, you have to make sure your thermostat is compatible with that of your electrical system.
  2. Now, start replacing the thermostat with turning off the electricity from the power panel. When you have figured out the right circuit breaker, you should make it secure with a piece of masking tape.
  3. In the next step, you will remove the old thermostat while pulling the cover off from the set of screws. Now, you have to pull out the device from the wall and then slide it off from the mounting plate. Don’t damage the wires while pulling the device from the wall.
  4. In this step, you need to dispose the power supply wire from the back of the unit. Wrap the wires around a pencil to ensure they don’t fall back into the wall. If you see there is no color code for each wire, you should mark them accordingly. And you should also keep a note of the terminal to which they were attached to. Finally, you should just remove the mounting plate.
  5. Now, you need to mount the new plate against the wall. Keep in mind this will be the same spot where the old thermostat was mounted. Next, you have to pull the wires from the wall and push them through the holes. Then you will screw and tighten the mounting screws. Make sure the adjustment of the device is perfect. Otherwise, the device will fall off the wall.
  6. At this moment, you will connect the wires. The green wire will go to the terminal ‘G,’ which operates the furnace fan blower. The white wire will connect to the ‘W’ marked terminal for operating the heater. As for the yellow wire, it will go to ‘Y’ terminal for connecting the air conditioner. If you don’t see any color-code, you should follow the labeling.
  7. The final step requires you to place the device on the mounting plate. You can do it while sliding the device into the place where you want to replace it. Now, you should read out the manufacturer’s instructions and set up the LED display panel. It will provide you with access to temperature control.

Bottom Line

If you have read so far, you now know how to install a thermostat. It means you have become a DIY person who is familiar with maintaining his or her own device.

As for keeping your thermostat in good shape, you can use the instructions above. They will help you in wiring, replacing the unit accurately. Not to mention, if you install it in the right way, it will provide you with better quality service.


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