Split Unit With a Slow, Unlocated Leak on a Record-Keeping Boundary
You service a small retail unit with a single split system charged with 4.2 kg of R-410A (GWP 2088). The owner keeps a logbook, but entries are sparse. On your visit you find the system low on charge and top it up with 1.1 kg. The last recorded leak check was 14 months ago. The owner tells you a technician 'did a check' last spring but there is no paperwork. The system has no leak detection system installed. The premises are a ground-floor shop with the outdoor unit on a rear wall and the indoor unit above a suspended ceiling, both accessible. The owner asks whether they can 'just keep topping it up' each year rather than finding the leak.
1. Is the owner's 'top up each year' proposal compliant? Explain the obligations that apply and state the CO2e of the system and of the top-up.
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No. Topping up without locating and repairing the leak is not a compliant strategy.
- Charge in CO2e: 4.2 kg × 2088 = 8,770 kg CO2e (8.77 t), which is above the 5 t CO2e threshold, so the unit is in scope of the leak-checking regime.
- Leak-check frequency: for a system of 5–50 t CO2e with no leak detection system, the check interval is 12 months. The last documented check was 14 months ago, so the unit is already overdue.
- Records: the check must be documented. An undocumented 'check last spring' cannot be relied on; the logbook must record the date, the result and the identity of the person who did it.
- Leak repair: where a leak is detected, it must be repaired without undue delay and a follow-up check must confirm the repair within one month.
- Top-up as evidence: adding 1.1 kg is itself a strong indicator of a leak and should trigger investigation, not just recharge.
Advise the owner that repeated top-ups increase cost, emissions and legal exposure, and that the correct path is locate–repair–verify–record.
2. If the leak is found and repaired, what follow-up and record-keeping steps must you complete, and how does the 1.1 kg top-up affect the records?
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Follow-up after repair:
- Carry out a verification check within one month of the repair to confirm the leak is fixed.
- Record the repair date, the nature of the leak, the parts replaced, and the result of the verification check.
Records:
- Log the 1.1 kg of R-410A added - quantity, date and reason. This is a charge addition and must appear in the logbook alongside the repair entry.
- Record the leak-check date and outcome so the next 12-month interval runs from the verification check.
- Keep records available for inspection; they should be retained for at least 5 years.
Practical point: the top-up quantity (1.1 kg, ~2,300 kg CO2e) is large relative to the charge and confirms a real leak. Documenting it protects both you and the owner and demonstrates that the leak was taken seriously rather than masked by recharge.