F-Gas leak-check interval calculator

Enter the refrigerant and charge to get the system's CO₂e and how often it must be leak-checked under GB F-Gas rules — with or without a fixed leak-detection system.

Indicative only. Leak checks must be carried out by an F-Gas certified person; confirm requirements against the current GB F-Gas rules for your equipment.

Leak-check interval

Not required

1.69 tonnes CO₂e

Below the 5-tonne CO₂e threshold — no mandatory periodic leak check, but keep your F-Gas records.

How the interval is decided

F-Gas leak-check frequency is driven by the global-warming impact of the refrigerant charge, expressed as CO₂e (tonnes) = charge (kg) × GWP ÷ 1000. The more CO₂e a system holds, the more often it must be checked. Fitting an automatic leak-detection system doubles the allowed interval because leaks are caught between manual checks. Full detail — including logbook and record-keeping rules — is in our F-Gas guide.

Frequently asked questions

How often must F-Gas leak checks be done?

Under GB F-Gas rules, frequency depends on the system's CO₂e: below 5 tonnes there's no mandatory periodic check; from 5 to under 50 tonnes it's at least every 12 months; from 50 to under 500 tonnes at least every 6 months; and 500 tonnes or more at least every 3 months. A fixed leak-detection system doubles the allowed interval.

How do you calculate CO₂e for refrigerant?

CO₂e (tonnes) = refrigerant charge in kg × the refrigerant's GWP ÷ 1000. For example, 3 kg of R32 (GWP 675) is 3 × 675 ÷ 1000 = 2.0 tonnes CO₂e. The calculator above does this for you and maps it to the required interval.

Who can carry out an F-Gas leak check?

Leak checks must be done by an F-Gas certified engineer using appropriate methods and equipment, and recorded in the system's F-Gas log. The interval is a legal minimum — you can check more often.

F-Gas scheduling, handled

Vento calculates CO₂e and schedules every leak check automatically — built into the platform you run the whole job on. Free for 14 days, no card.

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