While there is an array of smart thermostats on the market, they also cost a few hundred dollars. For someone who only wants a basic thermostat to control the temperature of their house, investing in smart thermostats isn’t a wise call.

Why invest hundreds of dollars when a much cheaper thermostat can do the job for you?

In that case, a manual thermostat may come in handy. Such thermostats don’t have a display or buttons to adjust the temperature. Instead, they rely on a simple twist action to raise or lower the temperature. They are available at a much cheaper price and work well as ever.

The CT87K1004 thermostat has a familiar circular design and simple twist action that helps you to easily adjust the temperature.

If you have ever considered buying a manual thermostat that doesn’t have a display or buttons to control the temperature, you should take a look at the Honeywell Home CT87K1004 thermostat. It is one of the oldest models that are still used by millions of people.

For a thermostat that cheap, you can’t be too picky. If you are looking for a basic device to control the heating of your home, the Honeywell Home CT87K1004 is worth considering. It doesn’t look fancy or complex to configure.

That said, we have written a detailed review of the Honeywell Home CT87K1004 thermostat. Have a look and then decide for yourself whether to buy it or not. Let’s get started.

Honeywell Home CT87K1004: What’s New

The Honeywell Home CT87K1004 is a classic round non-programmable thermostat from Resideo that is quite easy to use. It can be controlled manually with a simple twist action. The dependable, readable scale makes it simple to set the exact temperature and clicks at every 2-degree shift so you can see and hear the difference.

Here are the key specifications of the CT87K1004:

  • 3.62 x 3.62 x 2.88 inches
  • White color
  • Non-programmable
  • Heating function only

In the box, you’ll get a CT87K1004 thermostat, screws, solderless connectors for copper wires, an installation sheet, and a cover ring.


With a classic round shape, the Honeywell Home CT87K1004 is a non-programmable thermostat that measures 3.62 x 3.62 x 2.88 inches. The design is not too fancy but sports a circular figure with a large dial on the top. You can adjust the temperature of your home by manually twisting the dial.

The dial is big enough to clearly see the numbers and adjust the readings according to your preference. Overall, the design of the CT87K1004 gives a traditional feel and is easy to configure.


The Honeywell Home CT87K1004 thermostat is the most widely used thermostat in the world. Its recognizable round appearance and simple twist action make setting your optimum temperature quick and straightforward.

It is a heat-only type thermostat that delivers precise performance with the convenience of use you’ve come to expect — simply set the temperature on the dial and let the thermostat handle the rest.

The CT87K1004 thermostat was created with the user in mind, with a simple and accurate spherical shape that has been praised for its simplicity of use and precision. It is a simple and dependable way to control the temperature in your home.

The CT87K1004 thermostat is a modern classic that has earned its status as a high-level thermostat. It is mercury-free and features a stylish covering ring to disguise surrounding wall markings. It works with heating-only systems such as forced air (gas, oil, and electric), hot water and steam, and heat pumps without backup.

Let’s have a look at the few features of the Honeywell Home CT87K1004 thermostat.

  • Mercury-free thermostat with easy-to-use controls.
  • The world’s most common thermostat is Honeywell’s Classic Round style.
  • For heat-only systems, precise temperature control is essential.
  • The decorative wall cover ring that comes with the thermostat covers the markings left by the old thermostat.
  • Compatible with forced air (gas, oil, and electric), hot water and steam, and heat pumps without a backup.

One thing to note here is that the CT87K1004 is not suitable with electric baseboard heat (120-240V), heat pumps with backup, or multi-stage heating/cooling. It may not work with these systems.

Lastly, there’s not too much to talk about the features since it only has heating functionality.


The installation of the Honeywell Home CT87K1004 is a bit different than installing digital thermostats. If you are new to this, we would recommend you take the help of a professional. However, we have mentioned the steps below to install your thermostat.

Here’s how you can install the CT87K1004 in your home.

Step 1: To ensure the safety of your device, turn off the heating/cooling system at the main fuse/circuit breaker.

Step 2: Remove the cover of your old thermostat. You may have to unscrew the cover if it is locked on. 

Step 3: On the old thermostat, look for the heat anticipator adjustment scale and lever. You can use a standard setting for your sort of system if you can’t find the heat anticipator setting on your previous thermostat.

Step 4: Remove the old thermostat wall plate from the wall but do not touch the wires yet. 

Step 5: Use the wiring labels that came with the CT87 to mark the wires. Use the letter of the terminal on the old thermostat to identify each wire rather than colors.

Step 6: To protect the wires from falling back into the wall, disconnect them from the old thermostat and wrap them around a pencil.

Step 7: Using a level, attach the cover ring (optional) and a wall plate or sub-base to the wall. Wires should be pulled through the wire hole. Place the wall plate on the wall, level it, and mark the hole locations.

Step 8: Drill holes for the provided wall anchors (3/16″ for drywall, 7/32″ for plaster).

Step 9: Pull the wire through the wallplate, place it over the anchors, and then tighten the mounting screws. If desired, check the level. Use the leveling posts just below the Heat and Fan indications to level the sub base.

Step 10: After ensuring that the wall plate or sub-base is level, tighten the mounting screws.

Step 11: Loosen the screw terminals, then put the wires into the terminal block before tightening the screws.

Step 12: Push the extra wire back into the gap in the wall.

Step 13: Fill the hole in the wall with nonflammable insulation to keep draughts out of the thermostat.

Step 14: Using the label designations, connect the system wires to the relevant screw terminals.

Step 15: Remove the thermostat cover and secure it to the wall plate or sub-base.

Step 16: Remove the red plastic piece that holds the mercury switch in place.

Step 17: Slide the heat anticipator indication to 1.2 on the scale with a pencil tip.

Step 18: Place the thermostat on top of the wall plate or subbase so that the three captive mounting screws line up with the three raised screw holes on the wallplate or subbase.

Step 19: Remove the three captive mounting screws and tighten them. This completes the installation process of the CT87K1004 thermostat.

Congrats! You have successfully installed the Honeywell Home CT87K1004 in your home. You can now adjust the temperature by simply twisting the thermostat.

While installing the thermostat, however, make sure you aren’t installing the thermostat in a location where it can be affected by:

  • Any kind of drafts or dead spots behind your doors and in corners
  • Hot or cold air from ducts
  • Sunlight or radiant heat from appliances
  • Concealed pipes or chimneys
  • Unheated or uncooled areas including an outside wall behind the thermostat

Placing the thermostat in such a location can negatively affect readings and may show false data. The best tip is to place the thermostat about 5 feet (1.5 m) above the floor in an area with sufficient air circulation.

Also note that if this thermostat is replacing a control that contains mercury in a sealed tube, do not throw away the old one. For details on recycling and appropriate disposal of this control, or an old control containing mercury in a sealed tube, contact your local waste management authority.

How to check if the thermostat is working or not?

Since the Honeywell Home CT87K1004 has only a heating function, we need to make sure if the heating function is working perfectly or not. It ensures that the installation has been done properly. Any error during installation will cause the thermostat to go unresponsive.

Here’s how you can check if the heating function is working properly or not.

  1. Toggle the transparent dial to the leftmost position.
  2. Set the system switch to Heat if your CT87 has a sub base.
  3. Turn the dial until the temperature on the setting scale is higher than the temperature on the thermometer. The heating system should now start.
  4. Turn the dial until the setting scale temperature is lower than the room temperature displayed on the thermometer. The heating system should stop now.

The Good

  • Quite inexpensive
  • Easy to install and use
  • No batteries needed
  • Good for basic use

The Bad

  • Only the heating function is available
  • Not much accurate

Should You Buy the Honeywell Home CT87K1004?

Looking at the features and performance, the Honeywell Home CT87K1004 is the perfect thermostat for those who are looking for a simple device to adjust the temperature of their surroundings. The thermostat is very easy to use, just by manually twisting the dial on the top.

You don’t have to see a user guide or manual to learn how to control the thermostat. It doesn’t have batteries, takes roughly 10 minutes to install, and offers basic functionality.

That said, if you are looking for a thermostat with the above-mentioned features, the Honeywell Home CT87K1004 is the best option for you.


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