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

An air conditioner is a vital household appliance. If it develops a fault, it is best to find a lasting solution. This article discusses the problem of a Carrier air conditioner turning off.

Carrier air conditioner turning off

Carrier Air Conditioner Won’t Turn Off – How to Fix

Several faults can cause a Carrier air conditioner to keep running without turning off, even when you try to shut it off. One factor many people overlook is the size of the air conditioner. If the unit is too small, it will run almost all the time as it tries to keep up with the temperature demands. 

It is crucial to check the room size before purchasing the unit. That way, you can choose the correct capacity that befits the room. Otherwise, the compressor and fan motor will always run. The downside is that the constant running wears the air conditioner out sooner than it should.

However, if the air conditioner size is not the cause of the problem, check the following and fix faulty ones:

1. Condenser Coil

The air conditioner’s condensing unit is outside the house, so turn the circuit breaker off before touching it. Open the condenser and inspect the fins. If they are significantly dirty, use a vacuum cleaner with a brush attachment to remove dust and debris. Ensure you thoroughly clean them; if necessary, run water over the fins for a more thorough job. Also, clean the condenser fan and compressor while at it.

The job of the condenser coil is to transfer heat from the air conditioner out into the atmosphere. However, if it is coated with dirt, the dirt blankets it and prevents the efficient transfer of heat. As a result, the heat remains trapped and causes the air conditioner to run all the time as it tries to produce cool air.

2. Thermostat

Turn on the air conditioner and ensure you set it to the cooling function. Next, go to the thermostat and using a multimeter, test it to check for continuity. If you find no continuity, replace the thermostat.

The thermostat keeps an eye on the temperature of the air and throws a switch when it rises above a preset point. When it activates this switch, it allows voltage to flow to the compressor. However, if the thermostat becomes defective, it may not turn the switch off. Consequently, the cooling system keeps getting a voltage supply and running, causing the air conditioner to keep running.

3. Thermistor

Check the air conditioner’s thermistor. It is a small sensor fixed to the unit’s control board. It may be defective and in some cases, a fault with the sensor keeps the compressor up and running. Use a multimeter to check its continuity; replace the thermistor if it shows no continuity. 

The sensor detects the temperature of the air and alerts the thermostat when the temperature rises. If it sends wrong readings to the control board, the cooling system may keep running when not necessary.

4. Temperature Control Thermostat

Get a multimeter and test the temperature control thermostat to check its continuity. If it has a short, the thermostat will produce continuous continuity. And if this happens, you need to replace the thermostat because it is defective.

The voltage with which the compressor and fan run comes from the thermostat. If it becomes defective, the cooling system may continue receiving voltage, which keeps the air conditioner running longer than it should.

Additionally, check the temperature control board, the relay board, and the main control board. The relay board is responsible for providing voltage to several air conditioner components, including the compressor and fan motors. Replace any faulty control board, but ensure you verify it is no longer functioning before removing it.

Carrier Air Conditioner Turning Off – Fixed

If a Carrier air conditioner keeps turning off, consider the following components and fix defective ones:

1. Thermostat

The first thing to check is the thermostat setting. It may be incorrectly set, causing the compressor to turn off before the room is cool enough. If it is too cold, the room will cool too quickly and the compressor will turn off. Adjust the temperature setting on the thermostat and see if the air conditioner stays on.

If that does not work, the thermostat may be installed in the wrong place in the house. Positioning the thermostat in an area of the room that gets cool quickly tricks it into thinking the room is cold when it is not. Have a technician change the location and see if the unit stops turning on and off.

You may need a new thermostat if the above does not fix the problem. The thermostat may also need calibrating or rewiring if it does not need a replacement.

2. Air Filter

Typically, you should remove and replace the air filter in your Carrier air conditioner every three months or less if you live in a dusty area. If the filter is the reusable type, remove and wash it every two weeks or at most, every month. The impurities in the air block the filter over time, and while it is often overlooked, a dirty filter can cause serious issues with an air conditioner.

An air conditioner’s filter can get so dirty to the point of blocking the evaporator coil. And if the coil is blocked, it freezes and stops producing cold air. The air conditioner will turn off too quickly and come back on when there is a temperature need.

3. Refrigerant

The refrigerant in an air conditioner is the gas that produces cold air in the air conditioner. It flows through the unit’s sealed system, absorbs heat from the air while in the evaporator coil, and transfers to the condenser coil in the outside unit.

Typically, the refrigerant level should not drop because it does not deplete or evaporate. So, if there is a cooling problem, the first stop should not be the refrigerant. However, if the system springs a leak, the refrigerant level drops and the air conditioner starts shutting off too quickly. This problem should be fixed by a professional HVAC technician and should be done as quickly as possible.

4. Air Conditioner Size

Check the British Thermal Unit rating for your air conditioner and the size of the room where it is placed. If the unit is too big for the space, it will keep shutting off because it will quickly cool the room. Such an air conditioner does not need to run for an extended period before the air temperature drops, and when it happens, the compressor and fan shut off.

Check this article if you are unsure of the correct air conditioner size for your home. Apart from running up your energy bills, the constant tripping may cause humidity within the house to rise. Also, the house will have cold and hot spots all around.

Check out these other articles…

Carrier Air Conditioner Not Working [Proven Solutions]

How to Reset a Carrier Air Conditioner [Detailed Guide]

Carrier Air Conditioner Thermostat [Detailed Guide]

Carrier Air Conditioner Timer [Issues Solved]

How to Clean a Carrier Air Conditioner [Detailed Guide]

How to Service a Carrier Air Conditioner [Detailed Guide]

Carrier Air Conditioner Blowing Issues [Solutions]

Carrier Air Conditioner Turns On and Off – What to Do

Check the air filter, thermostat location and setting, refrigerant level, and air conditioner size if your Carrier air conditioner keeps turning on and off (refer to the above section). However, there are a few other parts to check, which can cause this problem.

1. Check the Evaporator Coil

If the coil is frozen, which can happen because of a low refrigerant level or a dirty filter, the air conditioner can turn off. If that is the case, disconnect the air conditioner from electric power and allow the coil to thaw. The same applies if the outside condensing unit is frozen.

2. Check the Condenser Coil

Take a vacuum cleaner with a brush extension and clean the outside coil. If the fins have a lot of dirt on them, there will be a heat overload, which may lead to the air conditioner shutting down. Do a thorough job of cleaning the fins and the fan as well. The air conditioner may start working after doing that.

3. Check the Drain Line

If the condensate drain becomes clogged with dirt, the drain pan fills. When it gets to a point, it triggers a float switch that turns off the unit. Therefore, check the drain pan and empty it if it is full. Also, clean the drain line and pan to improve the flow of condensate out of the air conditioner. Otherwise, the unit may keep tripping off and coming on again.

4. Check the Run Capacitor

A faulty run capacitor can cause the compressor to go off and on constantly. It is crucial to hire an HVAC technician to check the capacitor and replace it if necessary. The reason is that a capacitor tends to store electricity that needs to be discharged before it can be tested. If you are doing it yourself, use a multimeter to test the capacitor. Replace it if there is no continuity.

5. Check the Compressor

The compressor is the central part of an air conditioner. The functioning parts rely on it to run and without it, the air conditioner cannot work. Testing the compressor can be a bit challenging, so you may need a professional technician to check it or contact the Carrier Service Center for further assistance.

How to Turn Carrier Air Conditioner Off Without Remote

Locate the reset button on the air conditioner’s control panel and press it. Usually, the unit should stop running when you do that. The same process works if you want to start the unit. You can also use the power button on the air handler if it applies. It is crucial to consult the user manual for the air conditioner to learn other ways to turn on the unit without the remote control.

Carrier Air Conditioner Fan Won’t Turn Off – Quick Fix

Overheating can cause the condenser fan to run without stopping. But before deciding on that, check the fan setting on the thermostat. Typically, it should be set to Auto; that way, the air conditioner automatically turns it off with the compressor. If set to On, the fan runs all the time and does not turn off. Therefore, make necessary adjustments to the setting if it applies.

However, if the fan setting is not the issue, turn the temperature setting a few degrees higher than the current temperature in the room. The air conditioner should shut off, but if the fan keeps operating and the thermostat setting is Auto, there may be something else wrong with the fan.

Check the condition of the condenser coil. If it is significantly dirty, it means the condenser and air conditioner are overheating. Overheating keeps the fan running, so clean the condenser and compressor if applicable. It may help to use the services of a professional to do a thorough job.

The air filter may also be too dirty or the evaporator coil may be frozen. If none of these applies or you fix them and the fan keeps running, the refrigerant may be low. While you can clean or replace the filter and thaw the evaporator coil, you need professional help to check the refrigerant and charge the system if necessary.

Also, check the relay because it may be stuck. And while checking it, the capacitor may also need attention. In addition, the thermostat may need a replacement. Contact the Carrier Service Center and request service for the fan or employ the services of an HVAC technician for further assistance.

How to Turn Off a Carrier Air Conditioner

You can use the remote control to turn off the air conditioner. Press the Power control button to turn it off. If the remote control is not available, try setting the timer to turn the unit off automatically. Another method is to use the thermostat; press the Mode button to turn the mode of operation off. That keeps the unit from working. If none of these works, consult the user manual for instructions on how to turn the unit off, whether or not you are using the remote control.

How to Turn Off Timer on a Carrier Air Conditioner

Some Carrier air conditioners have a remote control with a CLR button. If you have set the timer for when the unit should turn off, especially if you are asleep. Press the CLR button once and the set timer will cancel out on the screen.

In some cases, you may see the timer on/off option on the remote. Use that to turn the timer off. Otherwise, consult the owner’s manual to see other ways to turn off the timer, especially as it concerns your specific unit.


If you have a problem with your Carrier air conditioner turning off, it is crucial to find a permanent solution. Check the thermostat, air filter, the size of the unit, evaporator coil, and refrigerant level. And if the unit will not turn off, check all the above, including the condenser coil and thermistor.

Follow this guide to fix problems with your air conditioner. If you are unsure about fixing it yourself, contact Carrier or hire a professional HVAC technician for further assistance.

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