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8 Common Reasons Why Your Aircon Compressor is Not Working

As temperatures rise, the importance of a functional aircon system becomes highly significant. The heart of this system is the compressor, a vital component responsible for pressurizing and circulating refrigerant to facilitate the cooling process. The aircon parts can also fail and stop working like any other machinery. Some common aircon issues include aircon compressor not working, aircon filters being too dirty, aircon thermostat not functioning properly, etc. 

However, when the aircon compressor fails, it can result in a cascade of issues, making the entire aircon system ineffective. This full-scale article will discuss eight common reasons aircon compressors may fail to operate and explore preventative measures to ensure the cooling system operates uninterruptedly.

Function of an Aircon Compressor

The aircon compressor plays a pivotal role in the cooling process, serving as the heart of the entire system. Its primary purpose is circulating and compressing the refrigerant gas, facilitating heat transfer between indoor and outdoor environments.

When warm air inside a building is drawn into the aircon, the compressor pressures the low-pressure, gaseous refrigerant. As the refrigerant is compressed, its temperature and pressure increase. The high-pressure, high-temperature gas then flows to the condenser coil outside, releasing heat to the surrounding air. This process transforms the refrigerant into a high-pressure liquid.

This cold liquid moves to the expansion valve, where it rapidly expands, leading to a drop in temperature and pressure. The low-pressure, low-temperature refrigerant is then sent to the evaporator coil inside the building, absorbing heat from the indoor air. The compressor restarts the cycle by compressing the low-pressure gas, repeating the heat absorption and release process. 

Aircon Compressor Issues and their Solution

This section will help you identify and fix aircon compressor problems with a DIY approach. Read the article through the end to learn about issues associated with aircon compressors not turning on.

Refrigerant Issues

A primary factor contributing to compressor malfunction is inappropriate refrigerant levels. Refrigerant, the lifeblood of your aircon system, undergoes a constant cycle of compression and expansion. 

Low levels due to leaks or improper charging can result in the compressor working harder, leading to overheating and eventual aircon compressor stop working. Routine maintenance checks, including refrigerant level assessments, can identify and resolve this issue before it enhances to the next level.

Electrical Problems

Compressors mainly rely on an efficient electrical system to function correctly. Faulty wiring, malfunctioning capacitors, or issues with the contactor can disrupt the electrical supply, hindering the compressor’s performance. 

Regular inspections by qualified technicians can pinpoint possible electrical concerns, allowing for timely repairs and avoiding compressor failure.

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Dirty or Blocked Coils

The condenser and evaporator coils are vulnerable to accumulating dirt, dust, and debris over time. This buildup disturbs proper airflow, reducing the system’s ability to exchange heat efficiently. 

As the aircon compressor works harder to compensate, it becomes prone to overheating and breakdowns. Regular cleaning and maintenance of coils are essential to preventing such complications and ensuring the longevity of the compressor.

Faulty Capacitors

The role of the capacitor is to provide the initial rotary magnetic field for the motor to start when connected to a single-phase supply. It would help to have a capacitor or inductor because the single-phase supply can produce pulsating torque, which cannot rotate the motor in one direction. Therefore, capacitors are pivotal in providing the initial electrical surge required to start the compressor. 

When problems like aircon compressor not working occur, they may be because of the failure of these components. Routine inspections and the timely replacement of capacitors can prevent starting-related compressor issues, increasing the overall reliability of the aircon system.

Contaminated Refrigerant

Refrigerant contamination, whether due to moisture or impurities, presents a significant risk to the compressor. Moisture can cause corrosion and damage internal components, resulting in the aircon compressor not working ultimately. 

Proper handling and storage of refrigerant and regular checks for contaminants are necessary measures to safeguard against this issue.

Overheating due to High Head Pressure

Excessive heat and pressure within the aircon system can cause the compressor to overheat. Malfunctions such as a faulty condenser fan, a clogged condenser coil, or inappropriate ventilation around the condenser unit can contribute to high head pressure. 

Routine maintenance and immediate resolution of these issues are crucial in preventing compressor overheating and subsequent failures.

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Incorrect Refrigerant Charge

Proper charging of the refrigerant is critical for optimal compressor performance. Too much or too little refrigerant can result in inefficiencies and eventual compressor failure. Professional technicians should handle refrigerant charging to ensure it synchronizes with the manufacturer’s specifications, preventing possible issues related to incorrect charges.

Age and Wear

Like any mechanical component, aircon compressors have a finite lifespan. Over time, wear and tear can affect efficiency, ultimately leading to failure. Regular maintenance practices, including lubricating moving parts, can enhance the compressor’s lifespan. 

However, identifying the signs of wear and planning for eventual replacement is a must to avoid unexpected system breakdowns.


If your problems include the aircon compressor not working, these steps are just for you. Maintaining a functional aircon compressor is paramount for a comfortable indoor environment. By understanding and resolving the common reasons behind compressor failures, homeowners can take active measures to ensure the longevity and efficiency of their aircon systems. Regular professional maintenance and prompt attention to emerging problems are crucial to preventing compressor failures and ensuring a relaxed and comfortable living space, especially during the hot and blazing summer months.