LS Aircon Servicing Singapore

Aircon Refrigerant Level

How to Check Your Aircon Refrigerant Level: Expert Tips

Maintaining optimal Aircon refrigerant levels in your air conditioning system is crucial for its efficiency and performance. Over time, refrigerant levels can drop due to leaks or improper installation, leading to decreased cooling capacity and higher energy bills. Checking and maintaining the refrigerant level is a task best left to professionals, but understanding the basics can help you identify potential issues early on. In this guide, we’ll explore expert tips on how to check your aircon refrigerant level and ensure your system operates at its best.

Understanding Aircon Refrigerant

Before diving into the checking process, it’s essential to understand what aircon refrigerant is and why it’s important. Refrigerant is a chemical compound responsible for absorbing heat from indoor air and releasing it outside, thus cooling the air inside your home or office. Common refrigerants used in air conditioning systems include R-410A and R-22, although newer systems are transitioning to more environmentally friendly options like R-32.

Signs of Low Refrigerant Levels

Aircon Servicing Singapore describes several signs indicating that your aircon’s refrigerant level may be low. These include reduced cooling performance, longer cooling cycles, warm air blowing from vents, and ice buildup on the indoor or outdoor unit. If you notice any of these signs, it’s crucial to check the refrigerant level promptly to prevent further damage to your system.

Preparation for Checking Refrigerant Levels

Before attempting to check the refrigerant level, ensure your air conditioning system is turned off and has been inactive for at least 30 minutes. This allows the system to stabilize, providing more accurate readings during the checking process. Additionally, gather the necessary tools, including a pressure gauge and refrigerant leak detector, to perform the task effectively.

Check Aircon Refrigerant Level

Using a Pressure Gauge

One of the most common methods for checking refrigerant levels is using a pressure gauge. This tool measures the pressure of the refrigerant in the system, providing insights into whether the level is within the recommended range. Here’s how to use a pressure gauge to check your aircon refrigerant level:

  1. Locate Service Ports: Identify the service ports on your air conditioning system. These ports are typically located on the outdoor unit and are labeled as high-pressure and low-pressure ports.
  2. Attach Gauges: Connect the pressure gauge hoses to the corresponding service ports. The low-pressure hose should be connected to the low-pressure port, and the high-pressure hose to the high-pressure port.
  3. Please turn on the System: Start your air conditioning system and allow it to run for a few minutes to stabilize.
  4. Read Pressure: Once the system has stabilized, read the pressure indicated on the gauge. Compare this reading to the manufacturer’s recommended pressure range for your specific refrigerant type. If the pressure is outside the recommended range, it may indicate a refrigerant problem.
  5. Interpreting Readings: A pressure reading significantly below the recommended range suggests low refrigerant levels, while a reading above the range could indicate overcharging. In either case, further inspection and possible professional intervention may be necessary.

Using a Refrigerant Leak Detector

In addition to pressure gauges, refrigerant leak detectors are valuable tools for identifying leaks that contribute to low refrigerant levels. Here’s how to use a refrigerant leak detector to check for leaks in your aircon system:

  1. Prepare the Detector: Ensure the refrigerant leak detector is properly calibrated and charged according to the manufacturer’s instructions.
  2. Inspect Connections: Visually inspect all connections, joints, and components of your air conditioning system for signs of leaks, such as oil stains or hissing sounds.
  3. Test Specific Areas: Use the leak detector to test specific areas where leaks are commonly found, such as refrigerant lines, valves, and fittings. Move the detector probe slowly along these areas, paying attention to any changes in the detector’s readings or alarm signals.
  4. Check Evaporator and Condenser Coils: Leaks can also occur in the evaporator and condenser coils. Carefully examine these components using the leak detector for signs of corrosion, damage, or leaks.
  5. Address Detected Leaks: If the leak detector indicates a leak, it’s essential to address it promptly to prevent further refrigerant loss and system damage. Consult with a qualified HVAC technician to repair the leak and recharge the refrigerant to the appropriate level.

Professional Inspection and Maintenance

While DIY methods can help you identify potential refrigerant issues, professional inspection and maintenance are crucial for ensuring your aircon system operates efficiently and safely. HVAC technicians have the expertise, tools, and resources to perform comprehensive inspections, detect leaks accurately, and recharge refrigerant levels as needed.

How to check Aircon Refrigerant Level

Regular Maintenance Tips

To maintain optimal refrigerant levels and prolong the lifespan of your air conditioning system, consider the following maintenance tips:

  1. Schedule Annual Inspections: Schedule annual inspections with a qualified HVAC technician to check refrigerant levels, detect leaks, and perform necessary maintenance tasks.
  2. Change Air Filters: Regularly replace air filters to improve airflow and prevent contaminants from entering the system, which can affect refrigerant performance.
  3. Keep Outdoor Unit Clean: Keep the outdoor unit free from debris, vegetation, and obstructions to ensure proper airflow and system efficiency.
  4. Monitor Performance: Pay attention to your aircon system’s performance, including cooling capacity, energy consumption, and unusual noises or odors. Any deviations from normal operation should be addressed promptly.
  5. Avoid DIY Refrigerant Handling: Do not attempt to recharge refrigerant or repair leaks yourself. Mishandling refrigerants can be hazardous and may void warranties.


Checking your aircon refrigerant level is an essential part of HVAC maintenance that contributes to efficient cooling and energy savings. By understanding the signs of low refrigerant levels, using appropriate tools like pressure gauges and leak detectors, and scheduling professional inspections, you can ensure your air conditioning system operates at its best and provides reliable comfort year-round.

Frequently Asked Questions

Switch off the aircon and find the service valves. Connect the manifold gauge set to these valves. Power on the aircon and monitor the pressure readings. In most systems, aim for a range of 30-40 PSI, although specific systems might call for different pressures, either higher or lower.
You can assess the charge by considering the unit's SEER rating, target superheat, DTD, CTOA, and whether it uses a fixed orifice or TXV.
Typically, professional HVAC contractors recommend Freon replacement for most systems every two to five years. However, a notable exception to this guideline occurs when there's a leak in the air conditioning system. Leaks lead to a gradual reduction in refrigerant levels in an AC unit over time.