How To Remove Old Honeywell Thermostat From Wall

Before installing a new thermostat, you need to remove your old analog thermostat, or you possibly have an old mercury thermostat.

To remove a Honeywell thermostat and replace it with one of the smart thermostats is relatively easy.

However, there are a few things to know first. Before removing the old thermostat from the wall, note the wiring, and check there are no extra wires attached. This helps when you come to install the replacement for the electrical system.


In our guide, you can learn all you need about how to remove Honeywell thermostat. It isn’t time-consuming, so it is a task that can take around an hour.

thermostat on wall

By the end, you’ll know how to remove thermostat from the wall safely and how to install a new one. (Read 5 Common Problems With Nest Thermostat)

How Do You Change An Old Honeywell Thermostat?

Before you start removing your old Honeywell thermostat, you need an understanding of the basic wiring of your thermostat.

Your thermostat has low-voltage wires, and your furnace circuit powers them. Each wire connects to a distinct part of the HVAC system.

These industry-standard HVAC coding schemes will show you where each wire should be connected.

  • The heating system is connected with the white wire.
  • The compressor is connected with a yellow cable.
  • The fan wire connects to the green wire.
  • An orange wire will correspond to it if you have a heat pump.
  • The common or C wire is blue.

While Red (C) ensures that your thermostat receives a consistent supply of 24 VAC power, the thermostat essentially performs the air conditioning function.

So, it connects to the cooling system, and the red (H) connects the thermostat to your heating system.

Steps For Honeywell Thermostat Removal From Wall

The steps here help on how to remove old Honeywell thermostat from wall.

1. Circuit Breaker

The circuit breaker for the entire HVAC system should be turned off. If you don’t turn it off, it could produce shocks when it reaches the wires.

2. Mercury Glass Vial

Your old Honeywell thermostat may contain a mercury glass vial. You should handle it cautiously because the glass may shatter, and mercury is poisonous.

Consult your local waste management organization for information on how and where to dispose of the thermostat. (Learn How To Remove Baseboard Heater)

3. Remove Thermostat Cover

To remove the cover, pull it off. Then, press the clips or tabs to remove the lid on some Honeywell thermostats.

However, you should first see if the Honeywell thermostat cover has finger grips or tabs that show how to remove it.

Take care not to pull the lid at an angle since this will cause it to shatter. Instead, wiggle it gently as you separate it from the base plate.

4. Label Wires

You should be able to view the terminals and cables after successfully removing the cover. If you don’t see them but see a plate, unscrew it with a screwdriver, and the cables will appear.

Check the electrical system before disconnecting anything and take a photo to help you remember how to rejoin them.

Cut small pieces of masking tape and name each one with the terminal of the wiring system to which it connects. As a result, installing the new Honeywell thermostat will be simple.

5. Remove Wires

The wires are usually kept in place by a screw. As a result, you’ll need to use a screwdriver to remove them. However, you can find push-in terminals and release buttons on some models of Honeywell thermostats.

To press them, you may need a sharp object like a ballpoint pen or a small screwdriver.

6. Remove Thermostat

Separate your Honeywell thermostat from the wall plate by pulling on the bottom.

To avoid breaking it, remember to pull firmly but not too hard. It should come free from the wall plate with the pull.

If your thermostat is screwed to the wall, remove the plate using a screwdriver.

The screws holding will leave patches and marks on your wall. However, you can repaint it, remove any old anchors, etc.

Before removing the Honeywell thermostat from the wall, ensure the circuit breaker is turned off.

Remove the cover first from the thermostat. Then, pull the thermostat away from the wall plate after carefully marking the wires with their terminals.

Now, in the reverse order, you can install your digital thermostat.

How Do You Remove A Thermostat From A Honeywell Home?

Heat and cool your home with Honeywell thermostats. If you’ve had your old thermostat for several years, it’s time to upgrade.

You can’t get it inside your home or business if your HVAC system is broken. Sadly, they need replacing every 10–15 years.

There are numerous reasons to remove an old Honeywell Thermostat from your wall. One reason is that your old thermostat fails, and you want to replace it.

Another reason is that it may be damaged and require repair. Or if you bought a new home and want to replace it to be more energy-efficient. Incompatible with other home automation products.


Thermostat Basics

If you are replacing your current thermostat, you should know the basics. Thermostats regulate temperature by activating electric heaters. It works like an air conditioner, with electrical control, but saves money.

Sensors on the control monitor indoor and exterior temperatures. If your old thermostat isn’t connecting with your modern heating system, it might reduce efficiency and raise utility expenses. (Learn How To Position Fans To Cool A Room)

The thermostat offers various wire colors for various works.

Honeywell thermostat wiring diagrams follow HVAC industry guidelines as they show you want wire works where, yet it is best to know how to use each wire.

Remove and replace a thermostat securely using this guide. A yellow wire connects it to your compressor.

The green wire runs the fan. The white wires are for the heating system.

It also features an orange wire for your thermostat’s heat pump. The blue thermostat wire is the common wire, while the red wire is the 24VAC power wire.

Step 1: Shut Down Power Supply

Disconnect the power to the entire HVAC system. Honeywell thermostats are wired heavily, and the company does not want you to be electrocuted when removing them from the wall.

Step 2: Remove Thermostat Cover

The second step is to remove the Honeywell thermostat from the mounting plate by unscrewing all visible screws. Remember where each screw went; you’ll need to put them later!

The Honeywell thermostat may fall forward off the mounting plate, so execute this step while seated. The Honeywell thermostat is too hard to remove from the mounting plate.

Four screws secure thermostats to a mounting plate. To keep water and dust out of your Honeywell thermostat, Honeywell put a small piece of plastic under each screw.

Step 3: Identify and remove wires

The thermostat wires are visible after removing the lid. The thermostat is unplugged from your HVAC unit.

Cut the masking tape into pieces and label each connected terminal. Be careful when removing thermostat wiring with a screwdriver.

Step 4: Remove Thermostat

Removing inside to remove the thermostat Terminals from the mounting plate is the last step to remove your thermostat, pull gently to remove your thermostat safely..

Two wires and one power cord secure Honeywell thermostats to a wall. If it won’t remove off the mounting plate, pull it hard.

It detaches from the wall or mounting plate. It’s constructed of plastic and can break if pulled too hard.

How To Remove Old Honeywell Thermostat From Wall (2)

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