Compressor Repair: Expert Aircon Troubleshooting and Repair Guide

The compressor is the heart of your air conditioner, and when it fails, you can be left sweating in the heat. Understanding what goes wrong with your aircon compressor can help you troubleshoot problems quickly and effectively. In this expert guide to compressor repair, we will discuss everything you need to know about the aircon compressor and its function. We will also provide tips on identifying common signs of compressor problems, troubleshooting them, and hiring a professional for compressor repair when needed. Additionally, we will delve into preventive maintenance techniques that can help prolong the life of your compressor and considerations for replacing it. So, let’s get started on understanding all there is to know about aircon compressors!

Understanding the Aircon Compressor

The compressor serves as the heart of an air conditioning system, working in conjunction with other components to facilitate the cooling process. Its primary function is to compress low-pressure, low-temperature refrigerant vapor, raising its pressure and temperature. This compression process is essential for efficiently removing heat from the indoor air.

Once the refrigerant is compressed, it becomes a high-pressure, high-temperature gas. This hot gas is then sent to the condenser coil located outside the building. In the condenser, the heat from the refrigerant is released into the outdoor environment, allowing the refrigerant to cool down and condense into a high-pressure liquid.

The high-pressure liquid refrigerant then flows to the expansion valve, which regulates its flow into the evaporator coil located indoors. As the refrigerant enters the evaporator coil, it undergoes a pressure drop, causing it to evaporate and absorb heat from the surrounding air. This process cools the indoor environment, and the now low-pressure vapor is returned to the compressor to start the cycle again.

Components of the Compressor:

  • Motor: The compressor motor provides the mechanical energy to drive the compression process. It is typically an electric motor that converts electrical energy into mechanical energy, allowing the compressor to function.
  • Compressor Housing: Compressor housing is a sturdy enclosure that houses various internal components and protects them from external elements. It also plays a role in reducing noise and vibration generated during compressor operation.
  • Piston or Scroll: Compressors can employ different mechanisms for compression, such as a piston or scroll designs. In piston compressors, one or more pistons move back and forth within cylinders to compress the refrigerant. On the other hand, Scroll compressors use two interlocking spiral-shaped scrolls to compress the refrigerant.
  • Valves: Compressor valves ensure the proper flow of refrigerant during the compression process. There are typically suction valves and discharge valves. The suction valve allows low-pressure refrigerant vapor to enter the compressor, while the discharge valve permits the high-pressure refrigerant gas to exit.
  • Lubrication System: Compressors require proper lubrication to reduce friction and wear between moving parts. Lubricating oil is circulated within the compressor to ensure smooth operation and prevent damage.

Signs of Compressor Problems

Several signs can indicate compressor problems in an air conditioning system. The compressor is a vital component responsible for circulating the refrigerant and maintaining the cooling process. Here are some common signs to look out for:

  • Warm air blowing: If the air conditioner is running, but warm or room temperature air is coming out instead of cool air, it could be a sign of compressor issues. The compressor may not be effectively compressing the refrigerant, leading to inadequate cooling.
  • Reduced airflow: A failing compressor may minimize airflow from the air conditioning vents. You might notice weaker or slower airflow compared to normal operation.
  • Strange noises: Unusual noises from the air conditioner, particularly from the outdoor unit where the compressor is located, can indicate compressor problems. These noises may include grinding, rattling, or screeching sounds, which could be caused by a faulty compressor motor or internal components.
  • Frequent system cycling: If the air conditioner frequently turns on and off rapidly (short-cycling), it could be a sign of compressor issues. The compressor may struggle to maintain the desired temperature, causing the system to shut down prematurely.
  • Increased energy consumption: A compressor not functioning properly may lead to increased energy consumption. If you notice a significant spike in your electricity bills without a corresponding change in usage, it could indicate compressor problems.
  • Tripped circuit breaker: A malfunctioning compressor can overload the electrical system, causing the circuit breaker to trip. If the circuit breaker associated with your air conditioner keeps tripping, it may be due to compressor issues.

Troubleshooting Common Compressor Issues

When dealing with compressor issues, it’s important to go through a systematic troubleshooting process to identify and resolve the problem. Here are the steps you can follow to address common compressor issues:

Checking for Power Supply Issues

  • Ensure the compressor is properly connected to a power source and the power supply works correctly.
  • Check the circuit breaker or fuse box to see if a tripped breaker or blown fuse is causing the power interruption.
  • Verify that the power switch or control panel settings are correctly configured.

Inspecting the Compressor for Physical Damage

  • Carefully examine the compressor for visible signs of physical damage, such as dents, leaks, or loose components.
  • Inspect the electrical connections and wiring for any signs of fraying, corrosion, or loose connections.
  • Clean any dirt or debris that may have accumulated on the compressor, as this can affect its performance.

Evaluating the Capacitor and Relay

  • The capacitor and relay are crucial components that assist in starting and running the compressor.
  • Check the capacitor for any signs of swelling, leakage, or damage. A faulty capacitor may lead to problems with the compressor starting.
  • Inspect the relay for burnt contacts or loose connections. Faulty relays can prevent the compressor from starting or cause it to overheat.

Testing the Compressor Motor Windings

  • Turn off the power supply before performing this test to avoid electrical shock.
  • Use a multimeter to measure the resistance across the compressor motor windings.
  • Refer to the manufacturer’s specifications or a service manual for the appropriate resistance values.
  • If the measured resistance significantly deviates from the expected values, it may indicate a problem with the motor windings.

Remember, if you are not familiar with electrical systems or lack the necessary expertise, it’s recommended to seek professional assistance. Working with compressors involves potentially dangerous electrical components, and improper handling can lead to personal injury or further damage to the equipment.

Hiring a Professional for Compressor Repair

Repairing or replacing a compressor requires specific technical knowledge, specialized tools, and experience. Professionals possess the expertise to accurately diagnose the issue, determine if repair is feasible, and carry out the necessary repairs safely and effectively. Their training ensures that the repair process follows industry standards, minimizing the risk of further damage and optimizing the performance of your air conditioner.

Selecting a reputable aircon repair service is crucial to ensure the quality of work and the reliability of the repair. Consider the following factors when making your choice:

  • Experience and Certifications: Look for technicians with extensive compressor repair experience and relevant certifications. This indicates their knowledge and commitment to maintaining industry standards.
  • Licensing and Insurance: Ensure that the repair service is licensed and insured. This protects you in case of any accidents or damages that may occur during the repair process.
  • Customer Reviews and References: Read customer reviews and seek references from friends, family, or colleagues who have used their services before. Positive feedback and recommendations are indicators of a reliable and trustworthy service provider.
  • Warranty: Inquire about the warranty offered for the repair work. A reputable repair service will stand behind their work and offer a reasonable warranty period.

To make an informed decision, requesting cost estimates from multiple aircon repair services is important. Follow these steps to ensure you get accurate estimates and can effectively compare your options:

  • Provide Detailed Information: Describe the problem you’re experiencing as accurately as possible when requesting an estimate. Include relevant details such as the make and model of your air conditioner, the symptoms, and any previous repair attempts.
  • Request Written Estimates: Ask each repair service to provide a written estimate that includes the labor cost, replacement parts (if needed), and any additional charges or fees. A written estimate ensures transparency and minimizes the risk of unexpected expenses.
  • Compare Estimates: Review the estimates carefully, considering the cost, reputation of the service provider, and the proposed solution for your compressor repair. Look for a balance between quality, affordability, and expertise.
  • Ask Questions: If anything is unclear in the estimates, don’t hesitate to ask for clarification. Seek information about the qualifications of the technicians, the quality of replacement parts, and any warranties or guarantees offered.
  • Consider Value, Not Just Price: While cost is an important factor, don’t solely base your decision on the lowest estimate. Assess the overall value offered, taking into account the reputation, expertise, and warranty provided by each repair service.

Preventive Maintenance for Compressor Longevity

Preventive maintenance plays a crucial role in ensuring the longevity of compressors. Regular cleaning of the condenser coils is essential as it helps remove dirt and debris that can impede airflow and reduce efficiency. Additionally, checking and replacing air filters is important to maintain optimal airflow and prevent the accumulation of dust and contaminants. One important aspect of compressor maintenance is monitoring power consumption to ensure that the compressor is operating efficiently. It is also important to monitor the humidity levels in the environment where the compressor is located to ensure optimal performance.

Another vital aspect is maintaining proper refrigerant levels to prevent overheating and damage to the compressor. Annual professional maintenance is highly recommended to identify and address potential issues, such as leaks or worn-out components before they escalate into major problems. Compressor longevity can be significantly enhanced by adhering to these preventive maintenance practices, leading to improved performance and reduced downtime.

Compressor Replacement Considerations

Several ticks should be considered when contemplating aircon compressor replacement in Singapore or elsewhere. Begin by assessing the age and condition of your current air conditioner before deciding whether to replace it outright or replace the compressor. Evaluate room size and cooling capacity (btu) when considering potential replacements. When to consider replacing the compressor:

  • Age and condition: If the compressor is old and has undergone multiple repairs, it may be more cost-effective to replace it rather than continue to repair it.
  • Frequent breakdowns: If the compressor frequently fails or requires repairs, it may be a sign of significant underlying issues, making replacement a more viable option.
  • Efficiency and performance: If the compressor is no longer functioning efficiently, resulting in increased energy consumption or inadequate cooling or heating, replacing it can improve overall system performance.
  • Cost of repairs: If the cost of repairing the compressor is high, especially compared to the cost of a new compressor, replacement may be a more sensible choice.

Factors to consider when choosing a new compressor:

  • Capacity and size: Determine the appropriate capacity and physical size of the compressor that matches the requirements of the system it will be installed in.
  • Energy efficiency: Look for compressors with high energy efficiency ratings, such as ENERGY STAR certification, to reduce operational costs and minimize environmental impact.
  • Compatibility: Ensure the new compressor is compatible with the existing system, including refrigerant type, voltage requirements, and control mechanisms.
  • Reliability and durability: Consider the reputation and track record of the manufacturer, as well as the compressor’s warranty and expected lifespan, to ensure long-term reliability and durability.
  • Noise levels: Compressor noise can be a concern, especially in residential or noise-sensitive environments, so selecting a compressor with low noise levels can be beneficial.
  • Cost: Evaluate the initial cost of the compressor, including installation expenses, and compare it with the potential energy savings and long-term benefits to make an informed financial decision.


In conclusion, to ensure that your aircon is running efficiently and smoothly, paying attention to the compressor is important. Understanding its mechanism, troubleshooting issues, and getting timely professional help are crucial steps toward maximizing the lifespan of your unit. Regular preventive maintenance will also go a long way in ensuring the longevity of your compressor. If you are facing any issues with your aircon compressor or need preventative maintenance services, contact our experts at Airmaxx Aircon for professional advice and assistance.