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Common Air Conditioning Compressor Problems & How To Repair It

A compressor in an air conditioner is the heart of the cooling system.

It is a vital component responsible for circulating and compressing the refrigerant, which is the substance that absorbs heat from the indoor air.

This high-pressure, high-temperature gas then flows to the front condenser unit, releasing heat to the outside environment.

As a result, the refrigerant condenses into a liquid state and travels to the evaporator coil, which absorbs heat from the indoor air, cooling it down.

If your indoor unit is not producing cool air, it can indicate that the AC compressor is facing some issues that must be fixed ASAP. But what can you do about it?

Join us as we break down common signs that your air compressor needs fixing and what you must do to ensure it gets repaired properly!

Signs that indicate AC compressors are facing issues

  • Hot air blowing: If the air conditioning system is running, but only warm air is blowing out of the vents, it could be a sign of compressor trouble.

  • Loud or unusual noises: A failing compressor may produce loud or unusual noises during operation. These can include grinding, rattling, or squealing sounds.

  • Frequent cycling on and off: If the compressor frequently turns on and off rapidly, known as short cycling, it could be a sign of compressor problems.

  • Increased energy consumption: A malfunctioning compressor can cause the AC system to work harder to maintain the desired temperature, resulting in higher energy consumption and increased utility bills.

  • Tripped circuit breaker: If the AC compressor is drawing too much electrical current or experiencing an electrical fault, it can cause the circuit breaker to trip.

  • Leaking refrigerant: Look for signs of refrigerant leakages, such as oily spots or stains near the AC unit or refrigerant lines.

  • Reduced airflow: A failing compressor can reduce airflow from the vents.

Common issues with air conditioner compressor units and how to fix them

Compressor wiring issues

Air conditioner compressors tend to have an issue where they either stop working or begin to hum. The problem occurs when the wiring in the compressor breaks, leading to failure.

The humming, ticking or clattering sound from the compressor can cause faulty air conditioning, leading to improper cooling and, worse, damage to the unit.

Exposed compressor wiring can also damage the entire air conditioning unit.


If this is the case with your aircon compressor, it is advisable to call a professional servicing company immediately.

In case of an emergency, while you wait for a professional to arrive, turn off the compressor, remove any outer covering from the outdoor unit and identify the wires within the thermal limiter.

If you need help during these steps, it is recommended to call a service company.

The compressor starts but keeps failing

At some point, the compressor may not start or start for a short while before failing. This aircon issue is usually caused by:

  • faulty capacitors

  • a malfunctioning motor

  • low refrigerant levels

  • a blocked refrigerant flow

  • constant wear and tear

These issues can lead to a lack of proper pressure and lubrication, causing the compressor to struggle or completely fail to initiate.


You can solve this aircon issue by finding a new fuse and replacing wires that were worn out. If this doesn't work, it could indicate the motor is burnt beyond repair.

Regardless, you should immediately consult a professionally qualified technician to check if the motor works properly.

Attempting repairs without proper knowledge can result in further damage to the system.

Failure of the compressor to run properly

The compressor's job is to circulate and compress refrigerant gas, generating heat during the process. However, if the heat is not effectively dissipated, it can cause the compressor to overheat.

When an air conditioner's compressor overheats, it strains the system excessively, leading to a breakdown.

Several factors can contribute to compressor overheating, including:

  • insufficient airflow

  • refrigerant leaks

  • dirty condenser coils

  • electrical problems


Regular maintenance, such as cleaning or replacing air filters, cleaning condenser coils, and ensuring proper ventilation around the outdoor unit, can help prevent compressor overheating and extend the lifespan of an air conditioner.

If the problem persists, investing in a new filter for the air conditioner is recommended.

After installing a new filter, open the supply vents to ensure proper airflow through the compressor's condenser and evaporator coils.

The motor does not start

The motor is critical in keeping the air conditioner compressor running, driving the necessary mechanical components to circulate refrigerant and cool the surrounding air.

When the motor fails, it can lead to a range of problems. For instance, excessive heat buildup may occur, causing the motor to overheat and ultimately fail.

Additionally, worn-out bearings or damaged windings can result in reduced efficiency, increased energy consumption, and, eventually, a complete motor breakdown.


Therefore, maintaining the motor's health through regular inspections and timely repairs is crucial to prevent compressor failure and ensure optimal air conditioning system's refrigeration cycle performance.

Failure in compressor bearings

The compressor's bearings are essential for smooth operation and reducing friction. Although uncommon, a failure in compressor bearings can produce unpleasant creaking noise.

Over time, wear and tear, lack of lubrication, or the entry of contaminants can cause the bearings to degrade.


When you hear any such sounds, make sure you find a bearing replacement for your compressor unit. If you leave it to run for an extended time, it could destroy the whole compressor.

Regular maintenance, including proper lubrication and timely replacement of worn-out bearings, can help prevent such failures and ensure the air conditioner's optimal functioning.

Mechanical failure of the compressor

This happens when the compressor locks and causes a general switch-off.

You will know when this happens since there will be a loud buzz that lasts for a few seconds, followed by a shudder. If you decide to check on the compressor, you will not find any open or failed short.


If this is the case, there are very few repair options you can consider.

Therefore, replacing the whole unit will be a viable option as long as the other parts of the aircon units are not old.

Before conducting this replacement, it is best to call a professional aircon servicing company to carefully inspect the entire aircon unit to ensure other parts did not induce this issue.

Worn-out compressors

Sometimes, the compressor could be fully worn out, old and damaged, resulting in decreased cooling capacity and unusual noises, such as rattling or grinding sounds.


Replacing it will solve everything.

The compressor comes with a serial number and a model number on its metal plate; note these numbers and shop for compressors with the same numbers.

If your warranty is not expired, make sure that you first take it back to its manufacturer for a free repair or free replacement!

Resolve your air conditioning compressor problems with 338 today!

It's always a good time to discuss the common issues an air conditioner compressor may face.

This way, you'll be able to spot problems with your unit and prepare for its replacement accordingly.

Find yourself facing one of these issues? Let us help!

338 Aircon Servicing Singapore is a highly recommended Aircon Company in Singapore, with many delighted customers and reviews over the years on Google and Facebook.

We provide an extensive range of Aircon Services, including Aircon Servicing, Aircon Repairs, Aircon Installation of the best aircon brands, Chemical Overhaul, Gas Top-up, Aircon Leaking Water, Aircon Not Cold Fix, and more.

We have a team of professional technicians equipped with over 15 years of knowledge and experience in the Aircon industry, completing thousands of aircon works for residential (Landed, Condo, and HDB) and commercial clients.

WhatsApp or call us at +65 8855 4141 for a transparent quotation and honest pricing that serves all your aircon needs!


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