Carrier Air Conditioner Thermostat [Detailed Guide]

The thermostat of an air conditioner plays a key role in how it functions. This article is on the Carrier air conditioner thermostat.

Carrier Air Conditioner Thermostat Not Working – Fixed

If you find that the thermostat for a Carrier air conditioner is not working, the first place to check is the circuit breaker. This is especially true if there was a recent power outage. Also, check the batteries if the thermostat is battery-powered. Wiring and electrical issues may also cause the thermostat to stop working; the same applies if the component is old. Check out this article on a Carrier air conditioner thermostat to find troubleshooting and repair instructions.

How to Reset a Carrier Air Conditioner Thermostat

If you are wondering how to reset a Carrier air conditioner thermostat, the steps are simple. However, you must know the type of thermostat you own; some are battery-powered while others are not. The powering system will determine how to reset it if there is no dedicated reset button, as this article explains.

How to Turn On a Carrier air Conditioner Thermostat

Check to see if the thermostat is battery-powered. If it is, buy the correct type of batteries for it. Consult the thermostat manual to determine the batteries to get. After getting them, open the cover of the battery compartment, usually at the back of the thermostat, and insert the batteries. Ensure you put them following the polar directions. Next, check for a power button and press it. The thermostat should turn on at this point.

But if the thermostat is not powered by batteries, check the user manual for directions. Some use WiFi, so you have to program it before using it. Others use electricity, so you need to connect it to an outlet to turn it on before using it. Ensure there is a nearby compatible outlet for the thermostat before mounting it.

How to Use a Carrier Air Conditioner Thermostat

Using a Carrier air conditioner thermostat is easy. Ensure there are batteries in it, and the batteries are working. If the thermostat uses electricity, ensure it is connected to a viable power outlet. Turn the thermostat on and set the temperature using the arrow buttons. Select the operating mode from the available list – cool, heat, dry, auto, fan. Set the fan speed according to the selected mode of operation.

Programmable Thermostats

If the thermostat is programmable, the first step is to set the date and time. Without setting them, you cannot access the features of the component. How you set the date and time depends on the thermostat model, and whether or not it has buttons or a touchscreen.

If there are buttons, open the access to activate the display. Look to the bottom right side and you will see a button marked d/h/m. Press it once and use the arrow buttons to select the day; press the button again to select the hour, and use the arrow buttons to choose it. Repeat the same process to set the minute. Close the access once you are done.

But if the thermostat has a touchscreen, touch the menu button or the screen to activate it. Next, press the arrow up and down buttons until you see Date. select it and use the same arrow buttons to select the day. Press Next and move to Month and Year in their respective order; the same goes for the hour and minute. Once you are done, press the Menu button once.

Mode Setting

After setting the date and time, the next step is to set the mode of operation. The thermostat will turn on the selected mode, but if you desire to change it, press the Mode button. Use the arrow keys to toggle up and down until you see the desired mode setting. You can choose between Heat, Cool, Auto, Dry, or Fan. if you choose Auto, the thermostat will activate the necessary mode, depending on the current temperature and set temperature.

Temperature Setting

After setting the mode, the next step is to set the temperature. The arrow up and down buttons allow you to choose the desired temperature, whether cold or warm. You may want to maintain the set temperature for some time, so use the hold/run button at the bottom. Hold it until Hold appears on the display. If you want to revert to RUn, hold the same button or touch the screen and hold the hold/run on the screen until Run appears.

WiFi Connectivity

Some Carrier Infinity, Comfort, and Cor thermostats allow you to connect to your mobile device or computer. Once you make a successful connection, you can remotely operate the air conditioner, setting the cooling or heating functions from anywhere.

To set the WiFi up, connect the chosen device to the WiFi network in the home. Next, go to the Apple App or Google Play Store and download the app for your device. Go to the thermostat and find the Menu. Press it and use the arrow buttons to select WiFi; press the buttons until WiFi flashes. Then, select it.

Next, press the arrow buttons again until you see scan WiFi. Select the option and give the unit some time to scan and find your home’s WiFi network. Once the WiFi name shows up, select it and press the arrow buttons again to find the WiFi password option. Select the option when it appears, and use the arrow buttons to find Change in the options. When you see it, select it and enter the password using the arrow buttons. Then, click Next to go to the next option.

You will see a Start button after successfully entering the password; press it to finish the setup. Look to the top of the thermostat’s display and the WiFi icon should flash at this point as it connects. The icon will remain lit once the connection is complete and it is in use.

Programming a Schedule

Some models allow you to program a cooling or heating schedule. It saves you the time you would have spent changing the temperature to suit a change in the weather. The steps to activate the programming features depend on the model, so it is crucial to consult the user manual for details.

Here is a video on how to program a Carrier thermostat…

Check out these other articles…

Carrier Air Conditioner Not Working [Proven Solutions]

Carrier Air Conditioner Turning Off [Issues, Solutions & Guide]

Carrier Air Conditioner Turning On [Issues, Solutions & Guide]

Carrier Air Conditioner Leaking [Quick Fix]

Carrier Air Conditioner Lock [Issues & Solutions]

How to Reset a Carrier Air Conditioner [Detailed Guide]

Carrier Air Conditioner Blowing Issues [Solutions]

Carrier Air Conditioner Thermostat Blank – How to Fix

Several faults can cause the display on the thermostat to go blank. Check the following and take the necessary steps to fix them:

1. Circuit Breaker

If a circuit breaker trips, it may be due to a power surge, faulty fuses, or too much load. The thermostat may be connected to a circuit with other devices and the load is too much. And if there was a recent power outage, it may explain the tripped breaker. Turn the affected breaker on or reset it to get it working again.

2. Float Switch

Most air conditioners have a protective switch that turns them off when there is too much water. Typically, humid weather leads to too much condensation from the air conditioner. The water should drain from the drainpipe, but if the pipe is clogged with dirt, the water remains in the unit. 

At some point, it triggers the switch and the unit turns off as a protective step. The thermostat may also turn off, so clean the drain pan and pipe to drain the water from the unit and turn on the air conditioner and thermostat.

3. Batteries

The batteries may be your first stop if the thermostat is powered by batteries. They do not quickly wear out, but over time, the batteries die. If they have been in use for too long, it may be time to replace them. Moisture is another factor that can quickly damage the batteries. 

Replace the batteries and see if the thermostat’s blank screen comes on, and if it does not, check the polarity of the batteries. Ensure you get the right types for the thermostat using the old ones as a reference. Then, ensure they face the correct directions; use the + and – signs inside the battery compartment and the batteries themselves to fix the polarity.

4. Wiring Connections

If replacing the batteries does not fix the problem or the thermostat is not battery-powered, check the wiring. Some connections affect how the display works and how the thermostat works in tandem with the air conditioner. If there is a loose wire in it, the display may go blank.

You may want to fix the thermostat issue yourself, especially if you have the skills. If you have the training, you can follow manual instructions to loosen and open and thermostat. You can recognize loose wires and fix them. However, if you do not have the skillset, it is best to hire a professional HVAC technician or contact the Carrier Service Center for further assistance.


If nothing else seems to work, you may need a new thermostat. One of the ways to know whether or not a thermostat is defective is to check the screen. A previously functioning thermostat may suddenly stop working if it has reached the end of its life, which may be over ten years. So, consider replacing the device; use professional services to determine the age and whether or not it needs a replacement.

Carrier Air Conditioner Thermostat Has No Power – Quick Fix

If you find that your Carrier air conditioner thermostat has no power, check its power source. If it is powered by electricity, ensure the circuit breaker is not tripped. But if it is powered by batteries, ensure they are still usable. 

Inspect the breaker controlling the thermostat to see if it is off. Turn it back on or reset it accordingly. Otherwise, replace the batteries to see if it comes on and works. Another option is to replace the thermostat.

Carrier Air Conditioner Thermostat Battery Replacement

Replacing the batteries in a Carrier air conditioner thermostat is a simple process. Find the lock tab at the center of the rim at the top of the thermostat. Run one hand along the top rim and you will find the latch. When you do, press the latch down to release the thermostat from the wall plate.

Pull the thermostat from the wall to remove it completely; tilt it forward a little and lift it up and off the wall plate’s lower lip. Next, put the thermostat down on a clean and flat surface and locate the batteries at the lower corner of the device, on the right-hand side. Lift the batteries and remove them from the compartment.

Now, get the new batteries and fix them in the battery compartment behind the thermostat. Check the polarity of the batteries and ensure it corresponds with that in the compartment; the plus and minus signs on the batteries must match those inside the battery compartment. Then, snap them into position.

Place the thermostat back on the wall; line the bottom edge with the wall plate’s bottom lip. The slot should fit over the plate’s lip when you do.

Carrier Air Conditioner Thermostat Wiring – Steps

A Carrier thermostat uses four colored wires with each terminal correctly labeled for connection. You will find Rc terminals, which control the cooling function, and Rh terminals, which control the heating function. In some cases, you may find red, green, yellow, and white terminals which may be represented by R, G, Y, and W. But they are basically the same as Rc and Rh.

There is also a terminal marked C, which does not have the same function as the rest. It is the terminal that takes the common wire that supplies a return path to the transformer. Through that wire, electricity can flow to the thermostat. The wire may be blue or black.

Using the standard color pattern, you can wire your thermostat to control the cooling and heating functions of the Carrier air conditioner:

  • Connect the red wire to the Rc or Rh terminals, which are typically bonded. This wire controls the primary power switch for the cooling and heating functions.
  • Connect the black C-wire to the C terminal. As explained, the wire is a return path to the transformer for power flowing through the red wire and the circuitry inside the thermostat.
  • Connect the white wire to the W terminal to switch on the heating function or switch it off.
  • Connect the yellow wire to the Y terminal. This function controls the compressor that powers the cooling function in the air conditioner.
  • Connect the green wire to the G terminal. This wire controls the air conditioner fan.
  • There is an orange wire and an O terminal. Connect the wire to this terminal to control the reversing valve that has the responsibility of turning a cooling pump into a heating pump.
  • There is also a B terminal and a blue wire (not the C-wire). Connect the wire to the terminal to control the reversing valve that has the responsibility of switching the unit back to its cooling function.

The user manual has a wiring diagram you can follow to wire the thermostat correctly. If there is a defective thermostat you have to remove before installing a new one, you can take pictures of the wiring before disconnecting anything. Then, the pictures will guide you when wiring.

While some thermostats have some variations that make them unique from others, most air conditioner thermostats have the same basic wiring pattern. For example, you may find some sophisticated thermostats, such as the Infinity thermostats, which have programmable climate control features and remote sensing. These types of thermostats may have slight variations from the basic wiring patterns, but others work the same.


A Carrier air conditioner thermostat is a vital part of the system. If it becomes faulty or stops working, the air conditioner may malfunction or you cannot control the functions. So, if you notice the thermostat is not working, check the power connection or batteries. Also, check the wiring; something may be internally loose. In some cases, you may have to replace the thermostat.

This article is also a guide on how to wire a thermostat without professional help. However, it is crucial to check the user manual or contact the Carrier Center for further assistance when installing a thermostat or wiring it. You will also find how to use or program the thermostat, especially if it is the Wifi-enabled type.

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