Service, Maintenance and Leak Detection
Leak detection in practice
You must know the methods and when each is appropriate. Electronic leak detectors suit general tracing; fluorescent dye assists finding persistent, hidden leaks; soap solution confirms a suspected leak point; pressure testing with OFN proves integrity after a repair. For systems where refrigerant cannot be safely added, a standing pressure or vacuum test may be used. Never use a naked flame as a leak detector - it is dangerous and can generate toxic breakdown products.
Routine maintenance duties
Leak checks at the frequency dictated by the CO2e charge, systematic inspection of joints, valves, flare connections and Schrader ports, and prompt repair of any detected leak. After a repair, a follow-up leak check must verify the repair before the system is returned to normal leak-check scheduling. Record every check, its method and its result.
Traps
- Frequency selection - candidates forget to convert kg to tonnes CO2e first.
- A repaired leak is not the end of the process - verification is required.
- Leak detection on A2L refrigerants requires awareness of flammability; detectors must be suitable for the gas.
- Recovered refrigerant from a repair must be handled as recovered, not vented, even in small quantities.
- Confusing a routine check with a post-repair verification check.
Rule of thumb
If you can smell or detect refrigerant, treat the system as leaking and act - but never rely on odour alone, since many HFCs are odourless. Detection is by instrument, confirmation by soap or pressure test, and closure by recorded verification.