Guide
F gas leak checks: how often your refrigeration plant must be checked
Updated
This is the duty that catches operators out, because the trigger is not the size of the plant or the age of the kit. It is how much warming potential is sitting inside the pipework.
How the frequency is worked out
Gov.uk states that how often you must check for leaks depends on the amount of F gas in the equipment and the global warming potential of that gas (Environment Agency and Defra). Multiply the charge in kilograms by the refrigerant's global warming potential, and you have the carbon dioxide equivalent in tonnes. That number sets your interval.
| Charge, carbon dioxide equivalent | Check at least | R404A | R410A | R134a |
|---|---|---|---|---|
| 5 to less than 50 tonnes | Every 12 months | 1.3kg | 2.4kg | 3.5kg |
| 50 to less than 500 tonnes | Every 6 months | 13kg | 24kg | 35kg |
| 500 tonnes or more | Every 3 months | 127kg | 240kg | 350kg |
- Automatic leak detection doubles the interval. Gov.uk gives the worked example: with leak detection fitted, equipment holding 5 tonnes of carbon dioxide equivalent is checked every 2 years rather than every year.
- At 500 tonnes or more, leak detection is not optional. The system must be fitted, and it must itself be checked every year (every 6 years on electrical switchgear).
- Hermetically sealed systems have no maximum period between checks unless they hold 10 tonnes of carbon dioxide equivalent or more, which gov.uk gives as 2.6kg of R404A or 7kg of R134a.
- Refrigerated trucks and trailers are in scope; refrigeration systems in other vehicles are not.
If a leak is found
Gov.uk is blunt about this: repair it as soon as possible, and repeat the test within a month to check the repair worked. It also states that you are breaking the law if you do not have the right leak checks in place or do not fix leaks, and that you could receive a civil penalty.
Records and certification
- Records, from 5 tonnes carbon dioxide equivalent
- Keep records for 5 years covering the quantity and type of gas at installation, gas added during maintenance, the dates and results of every mandatory leak check, and recovery and disposal, including the registered waste carrier used (gov.uk).
- Your contractors' certificate numbers
- As the operator, keep the name, address and certificate number of every company you use to install, service or decommission the equipment. The Environment Agency may ask to see the records during an inspection.
- Company certification
- A company, including a sole trader, must be certified by an approved body to service stationary refrigeration, air conditioning or fire protection equipment operated by others, and that certification is renewed every 3 years (gov.uk). A company servicing only its own equipment does not need it.
- Individual qualifications
- Every individual handling F gas needs their own qualification. Gov.uk sets out categories 1 to 4, where category 1 covers all activities and category 4 covers leak checking without breaking into the refrigeration circuit (gov.uk).
The F gas regime is not static. The figures above were read from gov.uk on 14 August 2026; check the current guidance before relying on a threshold for your own plant, and ask your contractor to confirm the carbon dioxide equivalent charge of each system in writing.