F-Gas Leak Check Intervals Explained
Updated: Oct 2
What UK Engineers Actually Need to Track
If you install, service, or decommission equipment containing fluorinated gases in the UK, you're required to carry out regular leak checks and to keep records proving you did. The rules trip people up not because they're complicated, but because the interval depends on a number most engineers don't calculate on site: CO₂ equivalent (CO₂e).
Why CO₂e, not just kilograms of gas
Refrigerants aren't equally harmful to the climate. A kilogram of R410A has a very different global warming potential to a kilogram of R32. F-Gas regulations don't care how many kilograms of gas are in a system they care about the climate impact of that charge, expressed as CO₂e.
CO₂e is calculated as:
Refrigerant charge (kg) × Global Warming Potential (GWP) = CO₂e
A system with a small charge of a high-GWP gas can trigger the same leak check frequency as a much larger charge of a low-GWP gas. This is the number that actually determines what you're required to do next.
The leak check bands
Once you know a system's CO₂e, F-Gas Leak Check Intervals generally fall into bands:
Under 5 tonnes CO₂e - no mandatory periodic leak check (though good practice still applies)
5 to under 50 tonnes CO₂e - at least every 12 months
50 to under 500 tonnes CO₂e - at least every 6 months
500 tonnes CO₂e and above - at least every 3 months
Systems fitted with an automatic leak detection system can have these intervals doubled. Always check the current in-force thresholds, as banding has shifted with regulatory updates over time - this isn't a set-and-forget number for your business.
What resets the clock
This is where a lot of paper-based record keeping falls down. Not every visit counts as a leak check for compliance purposes. A completed Service & Maintenance visit that includes a genuine leak check resets the clock. A reactive call-out, even one where refrigerant was topped up, typically does not, unless it specifically included a proper leak check against the system.
If your records don't distinguish between visit types, you can end up with a system that looks "checked" on paper but technically isn't compliant, because the visit that most recently touched it wasn't the right kind.
What a compliant record actually needs
For each check, you should be able to show:
The date of the check
The equipment identified (make, model, or unique reference)
The refrigerant type and current charge
The calculated CO₂e
Confirmation the check was carried out, and by whom
Any leak found, and what was done about it
Records need to be kept for at least five years and available for inspection.
Where paper and spreadsheets go wrong
The two failure points we see most often with engineers still on paper or spreadsheets:
The CO₂e isn't recalculated per visit. If a system's charge changes (top-up, partial recovery), the CO₂e should be recalculated but on paper this step often just gets skipped, and the wrong check interval gets applied.
There's no single source of truth per asset. If your job sheets live in a folder and your asset list lives in a different spreadsheet, nothing automatically tells you which systems are coming due. The reminder becomes "hope you remember," not a system.
The practical fix
Software that ties refrigerant data to the asset, not just the job, solves both problems automatically: every completed job recalculates the running charge and CO₂e, and the next leak-check due date is derived from the asset's actual history, not from memory.
That's the exact gap climateJob was built to close for self-employed and small AC & refrigeration teams: complete the job sheet on site, capture the refrigerant data, and the compliance clock updates itself, no spreadsheet, no separate logbook, no end-of-day admin.
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