How to install a new thermostat

A how-to guide for thermostat installation

A how-to guide for thermostat installation

When you need to install thermostat(s), the best thing to do is look at the instructions that came with your products. Unfortunately, many of these instructions seem to be written not for the layman, but for an experienced engineer.

Depending upon the type of thermostat, here follows some basic instructions for most models, which should help you with the installation.

If you have an existing thermostat that is connected to an electrical box, or runs off 120-volt current, you should not try to install a new one by yourself. There is too much risk involved with this much voltage, so it is best to call a licensed electrician. If, however, your existing thermostat is linked to smaller wires, then it runs off less voltage and you should be able to dismantle it and install a new one.

Take Down the Old Thermostat

Cut off the power going to the unit by removing the appropriate fuse to that area, or turning off the circuit breaker. Remove the cover from the unit. Now you can see inside. You’ll see some screws and wires. Find a screwdriver to match those screws. Note the wires are attached under the screws. In some models, the wires are color-coded.

Write Down the Model Number and Other Information

The next step in installing a new thermostat is to know what to buy to replace the old one. Write down all information from your old thermostat so you can pick out the new one properly. You may even want to take the cover off the old thermostat to the store with you so you can compare it to others.

Make notes on what is connected to what wire before you take the old one down. Buy your new thermostat if you haven’t already.

Match Up the Wires

Your new thermostat will most likely have some sticky labels included in the package. These are labeled “A”, “B”, “C,” etc. They are for the wires. Before you disconnect the wires on the old thermostat, label them to correspond to the new thermostat. This will become clear when you look at it. You want the “A” wire to go to the “A” on the new thermostat, etc.

In the event there are no labels provided with the new thermostat, just use masking tape and a felt tip pin to write your letter system.


Take The Old Unit Off the Wall

Using the appropriate screwdriver, unscrew the screws and detach the old unit from the wall.  To keep the wires from falling back through the wall after you take out the screws, simply wrap them all together around something like a ruler, pencil, spool of thread or whatever is handy.

Install Thermostat

Now that you have picked out your new thermostat from among the many choices at a retailer of heating supplies, it is time to install it. When you uninstalled the old one, you saw which wires it was hooked up to. You labeled them in the paragraph above.

Now it is time to match them up. Hold the base of the new unit up to the wall and thread the wires through. Attach the base to the wall using fasteners that are provided with the new unit. You may want to place a level on top to assure it is perfectly even and balanced.

Next, put the new screws in place, with the correct wire wrapped under each one, just as it was when you removed the old one. Sometimes you may have to cut the plastic off the end to get the wire to stay in place. Once you have all the wires connected, and the screws are tightly in place, check your owner’s manual to assure that everything looks as it is supposed to.

If everything appears fine, then you may turn the power back on and check the new thermostat. Place the cover on the unit and enjoy your new thermostat!


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