Leak Detection

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  • Always conduct visual inspections to identify potential for leaks.
  • Leak indicators can include oil spots/pools, dirt spots, missing port caps, etc.
  • Unidentified leaks lead to call backs & headaches.
  • Remember: Systems can have low refrigerant charge from simply connecting gauges over & over.


Due to the potential for leaks with R-22 equipment combined with the costly nature of call backs, and regulator fines: Always look to identify potential leaks before converting a system to TdX 20. Typically, a visual inspection of the unit + a baseline of system operation + sufficient standing nitrogen and vacuum tests will suffice in ensuring the system is tight and leak free. If leak indicators are found, use a leak detector, such as the Bacharach H-10 (Figure 1), to scan the system prior to converting.

Best Practices

  • Always conduct a visual inspection first, looking for oil spots and other signs of leaks.
  • When practical, baseline system operation to determine if the system is low on charge.
  • If there is a potential for a leak, use refrigerant leak detector to scan for leaks prior to recovery.
  • Always conduct sufficient standing nitrogen pressure tests (e.g. low-side nameplate pressure).
  • Use a trace amount of refrigerant with nitrogen charge to enable use of a leak detector.
  • Start with bubbles if system is not holding pressure.
  • Always conduct sufficient standing vacuum test.
  • Pay attention to the condenser coils when conducting a scan with a leak detector.

Additional Tips

  • When conducting a standing nitrogen pressure test, the pressure will change with temperature.
  • Use the standing pressure test calculator in the Bluon Mobile App to check pressure changes.
  • When using leak detector, work far-to-near from the suspected leak to pinpoint its location.
  • Calibrate leak detector sensitivity to filter out false alarms.
  • Shut off airflow when conducting leak detection.


Figure 1. Bacharach H-10 Pro leak detector.