Air Conditioner Error Codes – What Do They Mean And How To Fix Them

Air conditioning is used in almost every home. They keep us cool throughout the summer, except for when they stop working and an error code pops up!

Error codes tell us there’s a problem with our air conditioner that has to be fixed, but it’s not always easy to identify what’s wrong.

That’s why we’ve done all of the research for you. This guide will take you through the top 24 common error codes of an air conditioner, what causes them, and most importantly, how to fix them.

24 Common Air Conditioner Error Codes

You don’t have to be an AC or HVAC technician to notice if your air conditioner has a problem, because error codes are displayed on the control panel (but it’s more likely you’ll be suffering through the heat without a cool breath of air anywhere). All air conditioning systems contain a list of error codes that appear on the control panel when the unit is malfunctioning.

These particular error codes appear for a different reasons, and they can differ from one AC model to the next. Defrosting, refrigerant leakage, a malfunctioning sensor, or problems with the connections are some of the most common problems.

Many air conditioner brands use the same error codes, but there are some that have their brand-specific version. The error codes in this guide are for most brands, if yours doesn’t match with these then you are best grabbing a digital copy of user manual from your brand’s website.

Jump to your specific error code using the table contents at the start of this guide, or scroll down below.

ec error

An ec error code means there’s a refrigerant leak detection error on an air conditioner. This shows that the system has identified a leak.

It also usually means that the refrigerant pressures are either excessively high or excessively low in certain areas. 

Underlying causes:

• Refrigerant leak.
• Defective sensor.
• Printed circuits or a bad connection.
• Poorly maintained AC unit
• Insufficient refrigerant.
• Faulty fan motor or capacitor.
• Bad PC board.

How to fix a refrigerant leak causing an ec error.

• At the circuit breaker, turn off the electricity to the air conditioner. 
• Turn it off for ten minutes before turning it back on. 
• If the error code comes again, turn off the unit to avoid further damage and contact an air conditioner repairer to locate the leaks and repair the holes in the pipes. If they are extensive them you may need a new unit.

e0 error

When an air conditioner displays the ‘e0 error’ code, it means that an external unit protection device has been activated. 

Underlying causes:

• An issue with the outdoor circuit board (PCB).
• The refrigerant piping system is clogged.
• A motor lock for an outdoor compressor.
• Insufficient refrigerant.
• Error starting up the outdoor compressor.
• Locked motor on your outdoor fan.
• Electric expansion valve (EEV) malfunction due to overload or exposure to the elements.

How to fix an ‘e0 error’ on an AC:

• To clear the error code, press the reset button on the air conditioner’s control panel (check your user manual for the location on your specific model).
• Turn off the isolator switch at the outdoor unit for an hour.
• After the hour, turn the isolator unit back on.

Sometimes, the  e0 error code might repeatedly occur either with or without other codes. To fix a recurring e0 error code that is not accompanied with other codes:

• Disconnect the power supply cord and double-check that the power supply and ground wires are connected properly.
• Use a voltage tester to check the voltage.
• Make sure the air conditioning isn’t powered by a generator.
• Check to see if the air conditioner is connected to a properly grounded AC supply.
• Use a separate electrical circuit to power on the air conditioner.

Note: If the air conditioner still displays the error after these checks and repairs, you need to contact your customer service or AC/HVAC professional for assistance.

e1 error

An e1 error code on your air conditioner usually means there’s a problem with the controls, but the particular meaning varies by brand. The code is also often used as a reminder to replace the air filter.

If your air conditioner’s display panel reads e1 and it won’t switch on, it’s because the temperature sensor is shorted or malfunctioning, and you’ll probably need to get it serviced. 

Underlying causes:

• It’s time to change the air filter.
• It needs resetting.
• Internal connections are poor.
• The buttons are stuck.
• There is a malfunctioning control panel and a communication problem between the inside and outside equipment sections.

How to fix an e1 error on an AC:

• Check the connections on the control panel – Unplug the unit and look for charred or melted plastic traces on the control panel. Replace the control panel if any are visible. If the panel looks like it’s in good condition, unplug any leads and reconnect them to ensure appropriate connection.
• Clean the air filter – To clean the filter, turn off the unit, open the front panel and remove the filter. Reinstall it after cleaning it with soap and water and allowing it to dry. It’s time to replace it if you can’t get rid of all the filth and grease it’s accumulated.
• Check all the buttons – Sometimes, buttons get stuck, So, to correct this, push all of the controls. If you discover one that is stuck, simply unstick it, and the error code should vanish. Haier AC models are particularly prone to this.
• Reset the control panel – To reset the control panel, unplug the unit (for plug in AC’s) or turn it off at the switchboard (for hardwired AC’s) for at least one minute before plugging it back in.
• Do a hard reset – Some air conditioners are designed to display this error after a certain period of use. The AC unit requires a hard reset, cleaning, or replacing filters when this happens. To perform a hard reset, turn off the air conditioner, unplug it, and hold down the power button.  Continue to hold the button while reconnecting it to the power source. You’ll hear a beep after this sequence, at which time you can release the button, unplug the air conditioner, and plug it back in (or switch it on and off at the board).

If you try all the above procedures and your AC still displays the e1 error code, do this:

• Unplug the power cord from the outlet/turn it off at your switch board, then locate and press the “Mode” button on the control panel.
• Plug the unit back into the power supply/Turn it back on while holding down the “Mode” button (you may need someone else to help with this). Wait three seconds for the unit to beep.
• Release the “Mode” button; the unit should resume normal operation.
• Turn off the air conditioner by pressing the “Power” button. 
• To restart the unit, press the button one more time. 
• It should be reset with no error code and resume normal operation. 

Note: If you continue to have issues or cannot get the error number to remove, contact the manufacturer for more information.

e2 error

If your air conditioner displays an e2 error, it means there’s a problem with the external unit sensor. This problem is indicated by a small LED light on your air conditioner.

This problem happens when the evaporation temperature is lower than the cooling or dry mode temperature. The compressor and exterior fan motor both stop working as a result of this.

An e2 error on your air conditioner could also mean that the compressor’s pressure is too low.

Underlying causes

• The indoor unit’s filter is clogged.
• Dirt or obstruction on the evaporator coil.
• Filthy or damaged fan blower on your indoor unit.
• A broken fan motor in your indoor unit.
• Fan motor running at a slow speed.
• Low pressure.

How to fix an e2 error on AC

If the issue is low pressure:

• Clean the coils and filters.
• Make sure the power is on.
• Check the evaporator and condenser filters.
• Examine the evaporator and condenser coils.
• Check for refrigerant leaks and the level.
• Blocked duct.

If the issue is refrigeration leakage in the Outlet:

• Check the air return and entrance outlets to make sure the duct isn’t clogged at any stage.

If the issue is clogged coil due to obstruction:

• Remove the coil and clean it with a water pressure pump to return it to its original condition.

If the issue is a blockage in the indoor unit filter:

• Remove the filter from the unit and clean it with water.
• Examine your evaporator coil for any debris or obstructions. You can clean the cooling coil by removing it. To avoid unpleasant odors, don’t use chemicals.
• Make sure the air blower in your indoor unit isn’t clogged. Remove the blower for cleaning or replacement if it has a problem, such as a clog or a broken motor.

If the problem is a damaged or slow fan motor;

• You’ll need a qualified and experienced technician to examine the unit.

e3 error

When an abnormal operation protection error occurs, the e3 error code appears and activates to safeguard the unit from damage. It can also indicate a high pressure cut-out or a pipe temperature sensor checking channel problem.

Underlying causes

• A wiring mistake.
• Defective fan assembly.
• Defective fan motor.
• Defective control board.

How to fix an e3 error:

• To begin, inspect the wiring of the fan motor to ensure that it’s correctly connected and not loose.

Note: You might think that all manufacturers would use the same codes to make things easy for repair shops and customers, but this isn’t the case. Some error codes solutions differ from one AC model to another. Below are some examples of different air conditioner models with different meanings of e3 and how to fix them. They are as follows ;

• Midea AC model – if it displays an e3 error, it means that there is an indoor fan speed out of control or an error supplying power to the indoor unit. To fix that, check the signal connection cable using a motor rotation hand and replace the new motor for an indoor unit.
•  Lloyd AC – When there is a problem with the pipe temperature sensor checking channel, the Lloyd AC e3 error code appears. Calling the support center will help you find a solution to this problem.
• Gree AC – The E3 error on a Gree AC simply indicates a low refrigerant level in the Gree Inverter AC. Low pressure protection, refrigerant without protection, or recycling mode are some of the reasons for this. 

e4 error

In technical terms, the e4 error isn’t even an error. It basically tells you that your AC/HVAC system is in defrost mode. It can cause your unit to malfunction, resulting in an overly cold system.

Underlying causes

• A faulty outdoor or indoor temperature sensor.
• Unbalanced pressure.
• A faulty heat pump
• Your air conditioner is suffering from a lack of refrigerant (usually Freon).
• You have your air conditioner set to a temperature that is too cold.

How to fix an e4 error code on an air conditioner:

• Replace the air filters.
• Make sure you have enough power.
• Clean the evaporator and condenser.
• Hire a professional to check the refrigerant levels.

e5 error

When your air conditioner displays an e5 error, it means there is a full water collection tank. It’s one of the most common AC problems (for units with collection tanks), and it’s also one of the easiest to fix because it doesn’t require any actual repairs.

How to fix the e5 AC error code:

To fix the error, drain the water tank by:

• Remove the bottom drain cap and wait until all of the water has been emptied from the tank.
• Return the cap to its original position.
• Check to see if the error code is still present.

e6 error

A communication error code of e6 indicates that the inside unit is unable to communicate with the outside unit. This applies to both high and low voltage lines.

Underlying causes

• A problem with the wires that connect the internal and outside units.

How to fix the e6 error:

• Check the voltage on the external unit first.
• On the inside of the unit, check the voltage.
• Check for bad connections or an open wire in the communication signal wiring between the inner and exterior devices.
• Reset the thermostat on your air conditioner.

How to reset an AC’s thermostat.

• On the thermostat, turn off your air conditioner.
• Find the circuit breaker box.
• Restart your air conditioner by resetting the circuit breaker.
• Wait 30 seconds before continuing.
• Turn the air conditioner thermostat back on.
• If you cannot do it, call your HVAC’s customer care support or a HVAC technician to help you do it.

f0 error

The F0 error code on an air conditioner means your refrigerant gas level is low.

Underlying causes

• Leaks in the compressor or along the line.

How to fix an fO error:

• Turn the unit off.
• Turn it back on and reset it.
• Turn off the electricity at the breaker and call a competent engineer to fix the situation.
• The specialist will inspect your system for any leaks or other problems and provide you with a service that will involve a refrigerant top-up.

f1 error

An f1 error is used by some AC systems to indicate that the indoor and outdoor systems are unable to communicate with one another. 

However, some air conditioners use an e1 or f1 error as an ambient room temperature error. This means that the temperature sensor isn’t operating properly. 

On the other hand, an f1 error on a portable air conditioner indicates that the pump system is clogged with air.

Underlying causes

• Corrosion on connections.
• The isolator used on communication cables is not turned on.

How to fix the f1 error on AC:

• Where possible, check your user manual to determine what the f1 error means for your system as this error code does vary more between models.

If f1 is a communication issue:

• Make sure that all connections are clean and secure. Corrosion on connections can cause this error, so clean each one with light abrasive paper.
• Check that the connections are in the proper position. Wiring diagrams are printed on the interior of the indoor unit and on the PCB casing of the outdoor unit.
• Check for breakage in the black communication cable. If chock blocks or rotary isolators are used, double-check that the connections are secure and that the isolator is turned on.
• Contact a HVAC technician to replace both the indoor and outdoor PCB.

How to fix the f1 error on the portable air conditioner:

• Shut down the machine.
• Ensure that the pump connector is correctly installed on the unit.
• Make that the drainage hose is free of obstructions and kinks.
• Turn on the device.

f2 error

An f2 error code on your air conditioner indicates a problem with the indoor temperature sensor. 

Underlying causes

• Sensor issues.
• Defective electric control board.

How to fix an f2 error:

• Double check to know if the resistance of the sensor is normal. If it’s not, replace it.
• Check to see if the sensor wire is shorted or open and if the plug is touched correctly.
• Examine the electric control board for any welding off or rosin joints and fix it.
• Consult your user manual for more information.
• If you’ve checked everything and still can’t figure out what’s wrong, Make an appointment with an AC/HVAC specialist to take care of this for you.

f3 error

The f3 error code on an air conditioner indicates a problem with the external compressor sensor.

Underlying causes

• Wiring mistake.
• Faulty sensor.
• Faulty PCB.

How to fix an f3 error:

• Check that the connections between the sensors and the PCB are secure.
• Check the sensor sockets for contamination, as they are exposed to condensate water and can corrode.
• If you notice any corrosion, clean the sockets with a little abrasive brush.

f4 error

Your air conditioner’s error code ‘f4’ indicates a problem with the indoor fan motor or the indoor PCB.

Underlying causes

• Broken fan.
• Dirt in the cabinet.

How to fix an f4 error:

• Remove the AC from the power supply.
• Open the air valve and spin the fan blade by hand; it should spin freely without resistance or noise.
• You must replace the fan motor if the fan does not spin freely or detects grinding noise.
• If the fan spins freely and without making any noise, there is a problem with the internal PCB, which sends voltage to the fan motor.
• Check to see that the fan motor is securely linked to the PCB. You should replace the indoor PCB if the connections are in good working order.

f5 error

The f5 error code on the air conditioner means there is a problem with the outdoor fan speed.

Underlying causes

• A defective outdoor motherboard.
• A faulty outdoor fan motor.
• Outdoor unit fault.

How to fix an f5 error:

• Examine if anything is blocking the fan’s ability to spin freely.
• Check the motor of your outdoor fan.
• Check to see if the compressor’s connection is secure. If it isn’t, reconnect it firmly.
• Make that the connection between the Intelligent Power Module (IPM) and the coil is secure.
• Check to see if the compressor is working correctly, and if it isn’t, replace it.
• Check to see if the IPM is defective and if it is, replace it.
• Consult your user handbook or an HVAC professional if you’re not sure what to do.

f6 error

The f6 error code on your air conditioner means that an outdoor refrigerant is overcharged. Too much refrigerant in your air conditioner can damage the compressor. This is because the extra refrigerant will can concentrate inside the compressor, causing subcooling, or temperatures that are lower than normal.

Underlying causes

• Overfilled refrigerant.
• Poor repairs.

How to fix the f6 error:

• Turn off the air conditioner.
• Seek the services of a trained expert to drain out the extra refrigerant and fix any damage.
• Sometimes, to determine that you are dealing with refrigerant overcharge, look for the following signs; inefficient cooling, broken compressor, compressor noise, and high pressure readings among other signs.

h1 error

If your air conditioner stabilizer unit displays the code h1, it means that your appliance is executing a High Voltage Supply as a result of the high input voltage from the in-home mainline.

Underlying causes

• Faulty stabilizer.
• Faulty wiring.

How to fix an h1 error:

• Check the input voltage.
• Because the problem could be with the mains, try connecting the air conditioner directly to the grid.
• Reset the stabilizer.
• Hire a technician to come to have a look at your AC/HVAC.

h3 errors 

H3 is an error code associated with an air conditioner’s compressor. It usually occurs when the compressor is overloaded, which is known as a compressor overload protection error.

Underlying causes

• When the air conditioner is used in high-temperature or high-humidity settings.
• Dirty filters.
• Lack of regular maintenance of your HVAC system.

How to fix an h3 error:

• Consult the user manual for your particular AC model.
• Make sure the temperature in the room is below 90°F.
• Hire a AC/HVAC technician to inspect your unit.
• Consult your system’s customer care service.

h5 errors 

H5 is an air conditioner error code that indicates that the Intelligent Power Module (IPM) temperature is too high, the ambient temperature is too high, the voltage is too low, or the connections are poor.

To be sure what the problem or cause is, analyze the following:

• Check if the temperature in the room is too low.
• Check if the control or system is broken.
• Check if the interior and outdoor units’ connection cables and plugs are loose.
• Determine if the pressure gauge is blocking the refrigerant.

How to fix the h5 error:

• Check the refrigerant pressure and the pressure switch circuit for proper operation.
• Read the instruction handbook.
• If you’re not sure what to do, consult an AC/HVAC professional or contact your manufacturer’s customer care.

h6 errors

If your air conditioner displays an h6 error code, it means that the interior fan motor in your air conditioner is malfunctioning.

Underlying causes

• Indoor Fan Motor Failure.
• Issues on the computer board.
• Wiring issues.

How to fix an h6 error:

1. Turn off the electricity.
2. Look for anything that is preventing the fan blade from rotating.
3. Check if the fan blade revolves or is stuck after turning off the electricity to the machine.
4. Check the voltage.
5. Restart the unit.
6. Seek the services of an HVAC specialist to assist you in resolving the problem.

p1 error

The p1 error code on your air conditioner indicates an irregular increase or drop in voltage. The p1 code error indicates that the bottom tray is full on a portable air conditioner.

Underlying causes

• Faulty power supply.
• Incorrect power from the circuit breaker.
• There is a leak or a blockage in the system.
• Loose connections.

How to fix a p1 error:

• Turn off the electricity.
• Check the cords in your air conditioner to make sure they aren’t crossed or connected incorrectly.
• Check the power supply to ensure that the correct amount of electricity is going to the unit if the wires are correctly connected.
• Check that the circuit breaker is providing the correct voltage to the machine.
• Make that the power wires on the exterior condenser are appropriately connected.
• Verify that the control wires on the inside device are correctly connected.
• Make that the electricity to the main PCB board is working correctly.

How to fix a p1 error on portable AC:

• Carefully place the device near a drain, remove the bottom drain stopper, and allow the water to drain.
• Restart the unit until the “p1” symbol is no longer visible.

p2 error

When an air conditioner displays the p2 error code, it means that the refrigerant pressures are either too high or too low. This means that the main board detects overheating in the compressor and issues the P2 error.

Underlying causes

• Lack of refrigerant.
• A broken fan motor or capacitor.
• Poor ventilation
• Low Refrigerant 
• Sensor issues
• Board of the main PCB

How to fix p2 error:

• Look for anything that is obstructing the outside and indoor ventilation.
• Reset the device by turning it off and unplugging it for 10 minutes, then turning it back on to see if the issue has gone away.
• Check the temperature at the compressor’s top. The temperature should not exceed 212 degrees Fahrenheit.
• Look for any signs of a refrigerant leak.
• Look for low refrigerant levels.
• Check overload protector sensor.
• Examine the main PCB board for the outdoors.

p3 error

If your air conditioner has a p3 error code, it simply means that the ambient temperature outside is too low for your compressor to function.

Underlying causes

• The unit has a problem with the voltage or current.
• If the outdoor temperature is below -13°F for an extended period of time while in heating mode.
• Blockage in the system.
• Faulty wiring.
• If the external temperature is higher than -8°F for a few minutes and the compressor stops, a p3 error can result.

How to fix a p3 error:

• Check if the temperature outside exceeds the air conditioner’s operating range.
• Check to see if the current detecting circuit is defective; you should replace the electric control if it is.
• Check the power supply voltage is normal if the problem did not occur in standby mode.
• Verify that the voltage at the external terminal is normal.
• Check the power lines if the voltage isn’t right.
• Check if it is on standby mode because the main outdoor PCB may be faulty if the issue occurs while the system is in standby mode.

p4 error

The p4 error code usually indicates an unusual rise or drop in your system’s voltage. It can also imply that the refrigerant in your unit needs to be released.

Causes of p4 error:

• A compressor drive error might occur due to a faulty outdoor board, a faulty outdoor fan motor, or a compressor malfunction.

How to fix a p4 error:

• Turn off the unit.
• Wait for a few minutes and turn it back on.
• Go to the outdoor unit if the situation persists.
• Remove the side wiring cover and use a multimeter to check the voltage of the system unit.
• Consult the user manual or your system’s customer care.

Note: Hire a AC/HVAC technician to do this for you if you are not sure what you are doing.

p5 error

When your air conditioner displays the P5 error code, it initiates conflict mode, which means one of your indoor units is in cooling mode while the other is in heating mode.

Underlying causes

• Clogged drain line or drain tap.
• Blocked air flow causing water to overflow.
• Failed condensate pump.
• Improperly installed drain lines.

How to fix a p5 error:

• Power off the AC.
• You will need to restart your AC unit because the indoor unit cannot operate under two different modes (heating and cooling) simultaneously.
• Set all of your indoor units to cool and run them all at the same time for a short time.

Conclusion.

There are a lot of different AC error codes, but if you have a basic understanding of what the error codes mean, you can often fix your problem yourself. If you are unable to do the task on your own, seek professional assistance.

Ultimately, there are many error codes, but we have not listed all of them because they are different across different manufacturers and models in the air conditioning sector. So we advise that you read your user manual carefully or contact your brand’s customer service before doing anything with your air conditioner.