How to Fix E3 Error in Midea Air Conditioner?

How to Fix E3 Error in Midea Air Conditioner?

The E3 error in Midea air conditioners indicates a fault related to the indoor heat exchanger midpoint temperature sensor. This sensor plays a critical role in monitoring the temperature of the indoor evaporator to ensure proper cooling operation. When the unit detects an abnormal reading or loses connection with this sensor, it triggers the E3 error code and may reduce cooling performance, start and stop irregularly, or even shut down to prevent further damage.

What Does the E3 Error Mean?

The E3 error usually signals one of the following issues:

• Temperature sensor disconnected or improperly connected
• Short-circuited or malfunctioning temperature sensor
• Damaged or faulty main Printed Circuit Board (PCB)

It is important to note that a faulty reading does not always mean the sensor itself is broken. Problems can also arise from wiring issues, loose connectors, or faults in the electronic board interpreting the sensor data.

Common Symptoms of the E3 Error

• The air conditioner starts and stops unpredictably.
• Poor cooling or inconsistent temperature regulation.
• In inverter models, irregular compressor operation and fluctuating performance.
• The unit may lock or shut down shortly after turning on.

Possible Causes of the E3 Error

The causes behind the E3 error include:

• Indoor heat exchanger midpoint temperature sensor failure: This small but crucial sensor can fail, sending incorrect or no signals.
• Sensor connection issues: Loose connectors, damaged cables, or deteriorated solder joints caused by heat, vibration, humidity, or dust.
• Main PCB damage: Faulty electronic components, damaged traces, or unstable input readings on the control board.
• Environmental factors: While dirt buildup, internal humidity, or poor maintenance do not directly cause E3, they can contribute to unstable sensor readings.

Step-by-Step Guide to Fix the E3 Error

Step 1: Verify the Sensor Connection

1. Turn off the air conditioner and unplug it from the power source.
2. Open the indoor unit carefully to locate the indoor heat exchanger midpoint temperature sensor.
3. Check that the sensor is firmly connected to the corresponding port on the main PCB.
4. If the connection is loose or disconnected, reconnect it securely.
5. Close the unit, restore power, and check if the E3 error clears.

Step 2: Measure the Sensor Resistance

If the error persists, the sensor may be faulty. To test it:

1. Turn off and unplug the unit again.
2. Open the indoor unit and disconnect the temperature sensor from the PCB.
3. Using a multimeter, measure the resistance of the sensor.
4. An abnormally low resistance reading indicates a short-circuited sensor that must be replaced.
5. An infinite or unchanged reading may signify an open circuit or sensor failure.

Step 3: Inspect and Test the Main PCB

If the sensor appears to be functioning correctly but the E3 error remains, the main PCB may be damaged. The board may misinterpret sensor resistance or fail to process the signal properly due to subtle component deterioration or damaged traces.

PCB diagnosis and repair typically require professional technical expertise. Depending on the severity of the damage, the PCB might need component-level repair or full replacement. It is important not to attempt such repairs without proper knowledge, as this could worsen the problem.

Additional Tips Before Replacing Parts

• Reset the Unit: Sometimes, a transient error caused by voltage spikes or power outages can be cleared by fully shutting down and restarting the unit. However, if the E3 code reappears frequently, a deeper issue exists.
• Observe Unit Behavior: Intermittent sensor failures may cause irregular symptoms like occasional loss of cooling or brief protection-mode activations, helping differentiate between minor glitches and real faults.
• Clean the Indoor Unit: While dirt and clogged filters don’t directly cause E3, cleaning the unit reduces noise in the diagnosis and improves overall sensor environment stability.

When to Call a Professional

While checking connections and measuring sensor resistance are accessible steps, handling PCB repairs, live voltage tests, or board replacements require technical skills. Incorrect handling can cause further damage or affect other parts of the air conditioner.

Summary Table of the E3 Error

Other Error Codes in Midea Air Conditioner

For help identifying and solving other Midea air conditioner error codes, you can use our free error code finder tool available on our website.