6 Nov 2024

Refrigerant Pipe Leak Repair

Recommended for systems that have undergone system analysis and found to have leaking pipework.

1. Preparation

Gather Equipment: Assemble all necessary tools and materials, including a refrigerant leak detector (electronic or ultraviolet (UV) dye and light), soap solution, manifold gauge set, repair tools (e.g., welding or brazing equipment), and replacement refrigerant.

2. Initial Inspection

Visual Inspection: Begin with a thorough visual inspection of all accessible refrigerant lines, joints, and connections for signs of oil residue, corrosion, or physical damage, which can indicate potential leak points.

3. Using a Refrigerant Leak Detector

Electronic Detector: An electronic leak detector is sensitive to the presence of refrigerant gases. Slowly move the probe along the refrigerant lines, paying close attention to joints and connections. The detector will alert you to the presence of refrigerant.

4. Repairing Leaks

Small Leaks: For minor leaks at joints or connections, it may be possible to repair them by tightening or replacing fittings.

Welding or Brazing: Larger leaks or those in the piping may require cutting out the damaged section and welding or brazing a new piece of pipe. Ensure the area is clean and free from any refrigerant or oils before welding.

Replace Components: In some cases, it may be necessary to replace the entire section of piping or faulty components. Additional charge applies.

Vacuum the System: Once repairs are completed, use a vacuum pump to evacuate the system. This removes air and moisture.

5. Post-Repair Testing

Checking for leaks: Hold the Vacuum: After the vacuum process is complete, turn off the vacuum pump and observe the pressure reading on the gauge for a few minutes. If the pressure remains stable, the system is likely free of leaks. If the pressure increases, it indicates a leak that must be located and repaired before proceeding.

6. Recharge Refrigerant

Calculating Refrigerant Quantity: Determine the factory-specified refrigerant charge for the system, typically noted on the data plate of the outdoor unit. Adjust for the length of the piping as necessary, using guidelines found in the manufacturer’s installation manual.

Refrigerant Cylinder Preparation: Place the refrigerant cylinder on the scales and connect the yellow hose to the cylinder. Open the cylinder valve slightly to purge air from the hose, then close the valve.

Initiating Charging: Open the low side valve on the manifold gauge to allow the refrigerant to flow into the system. Monitor the scales to ensure the correct amount of refrigerant is added.

Finishing the Charge: Once the specified weight of refrigerant has been charged, close the manifold gauge valves, and disconnect the hoses.

7. Final Checks and Start-up

Re-check for Leaks: Perform a final leak check to ensure system integrity.

Start-up the System: Restore power to the air conditioning unit and start it. Observe the operation for a few minutes to ensure it is functioning correctly.

Performance Check: Measure the temperature drop across the indoor unit to assess cooling performance, including suction line temperature and pressure, FCU return air and off-coil air temperatures, and superheat value.