When my Honeywell thermostat broke down after 6 years I was completely lost as to what to do. I did not have any idea about how to remove the old Honeywell Thermostat from the wall.

But when my husband finally taught me how to remove it I understood that removing the Honeywell thermostat is a piece of cake.

Do you want to remove your old Honeywell thermostat from your wall but do not know where to start? With this guide, you will learn all the tips and tricks on how to easily remove your old thermostat from the wall.

Understanding The Wiring Of The Thermostat Is Key

Before any thermostat is installed or removed, the wiring is the first thing that you have to know about. If you are afraid of wires, you have nothing to worry about.

This is because the wires in the thermostat have low voltage.​​ The furnace circuit powers the wires of the thermostat.

There are many wires inside a thermostat and you can identify them using industry-standard guides:

  • White wire: This regulates the temperature so it connects with the heating system.
  • Yellow wire: This controls the compressor.
  • Green wire: The fan is one of the most important parts of any thermostat and this wire connects to the fan.
  • Orange wire: If your thermostat has a heat pump then the orange wire will connect to it.
  • Red wire: The Red (C) wire ensures that 24 VAC is supplied to the cooling system. The Red (H) supplies 24 VAC to the heating system.
  • Blue wire: This is commonly known as the common wire or ‘C’ wire.

Check The Power Supply And Circuit Breaker

Before you do anything else, check the power supply and turn it off. Even though the wires have low voltage, your power supply should be off to prevent any accidents.

After you check the power supply, check the circuit breaker. The circuit breaker should be turned off so that you do not get any shocks.

Often when thermostats become old, the circuit breakers do not work properly. So if you have an old thermostat then recheck your circuit breaker.

Look For The Glass Vial

If you have an old version of the Honeywell thermostat, you should be extra careful. This is because most old thermostats have glass vials that contain mercury.

So before you remove the thermostat from the wall, make sure that you remove the glass vial.

The glass vial with the mercury is called the mercury switch and the mercury conducts electricity. Be careful when removing the glass vial so that it does not break. After the glass vial is removed, do not throw it in your trash.

As it contains mercury, it will harm the environment. You can contact the thermostat recycling company or take help from your local waste management authority to know how to dispose of it.

Remove The Cover Of The Honeywell Thermostat

To uncover the wire and bracket, the cover of the Honeywell thermostat must be removed from the wall. You can usually just take the thermostat straight away from the wall on most models.

Pull forcefully against the wall, being careful not to rip the base off at the same time. To release the lid, you may need to press a button or latch on some thermostats.

The wires and terminals should be visible after removing this cover. If the wires are not visible, search for a plate that’s been bolted in place and can be removed with a screwdriver.

Mark The Wires

Once you take the cover out, you will be able to see all the wires and terminals. The first thing you should do is click a picture so that you will be able to connect them in the same way for the new thermostat.

Next take some painter’s tape and cut them into small sections. Label them with the terminals of where the wires connect to and put them on the wires. This will make it easier when you install a new thermostat.

Removal Of Wires And Brackets

To finish removing the thermostat, carefully separate the connections. You will need a screwdriver to remove them because they are usually kept in place by a screw.

Others employ push-in terminals with a release button that can be pressed with a small screwdriver, ballpoint pen, or other similar instrument.

Make sure not to take the labels away from the wires. Remove the remaining wall plate, as your new thermostat will have its own bracket.

If your new thermostat is a different size than the old one, make any necessary repairs, such as removing old anchors, fixing holes, and touching up paint.

Remove The Honeywell Thermostat

Once all your wires have been disconnected and the cover is taken off, gently lift the thermostat from the wall. Do not pull it as it might break. Once the thermostat comes out you can check if the wall is damaged or not.

You can repaint the wall or fix the holes easily so there is nothing that you should worry about.

Frequently Asked Questions

1. After how many years should I replace my thermostat?

You should replace your thermostat when it is not working properly or has some problems that cannot be fixed for a long time.

2. Can I fix the wiring instead of replacing my thermostat?

Yes often repairing the wires solves the problem however it is advisable to replace your thermostat for a better performance.

3. Can I throw away the mercury thermostat?

No you should not throw away your mercury thermostat as it is extremely harmful for the environment.


The Honeywell Thermostats that I used have kept me warm even on the coldest days. It is the one thing that kept both my house and heartworm from all the chill outside.

So when the time came to remove the old Honeywell thermostat from the wall, I did get a little teary eyed. But with the new Honeywell thermostat, I am even happier.

So I hope that this guide will help you with the problem of how to remove old Honeywell Thermostat from wall.

Dominic Wong

Dominic Wong, holding a Master’s in Electrical Engineering from Stanford University, has 20 years of experience in the home appliance sector. He joined our website as a freelancer in 20119, sharing his deep understanding of appliance functionality, energy efficiency, and consumer trends. Previously, Dominic worked in appliance design and testing. His background also includes roles in product development and consumer research. An advocate for sustainable technology, he enjoys mountain biking and experimenting with smart home gadgets in his spare time.

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