F-gas rules: what to check about your installer

Who is allowed to install air conditioning?

GOV.UK says you must have your own qualifications to work on equipment containing F gas, even if you work for someone else, and that working without them can lead to a civil penalty. The qualification comes in four categories:

• Category 1: all activities
• Category 2: installing, maintaining and servicing systems holding less than 3kg of F gas, or less than 6kg if hermetically sealed
• Category 3: recovering refrigerant from those smaller systems only
• Category 4: checking for leaks without breaking into the circuit

The company certificate

A company, including a sole trader, must be certified to install, repair, maintain or decommission this equipment for other people. The certificate comes from an approved body. For air conditioning and heat pumps, GOV.UK lists Refcom, F-Gas Register (Quidos) and Bureau Veritas. To get it, a company must show that it has enough trained staff and a written procedure for handling F gas, and it must renew every three years.

What to ask an installer

• The company's F-gas certificate number and the body that issued it, which you can check with that body
• Who will actually do the refrigerant work, and their personal qualification
• How the electrical work will be certified under Part P
• What record you will get of the refrigerant type and amount
• Ask the same of us

A cheap "fit it yourself" kit may leave you needing a qualified person to finish it, so check before you buy. Pre-charged units still have to be installed and handled within the rules.

Leak checks and records

Whether your system needs a legal leak check depends on the climate impact of its refrigerant, measured in tonnes of CO2 equivalent:

R32 has a global warming potential of 675, so 5 tonnes is about 7.4kg of R32. R410A, at 2,088, reaches it at about 2.4kg. Most single home units fall below the threshold, but the label on the outdoor unit tells you the charge. Operators of systems above it must keep records of the refrigerant, service work and leak checks for at least five years. Any leak found must be repaired as soon as possible, with a further check within a month.

Which refrigerants new systems can use

Since 1 January 2025, single split systems holding less than 3kg of F gas with a global warming potential above 750 cannot be placed on the market in Great Britain. That rules out R410A in new single splits, and R32 is now the common choice. Existing R410A systems are not banned, and they can keep running and be repaired. Portable units using HFCs with a potential above 150 are banned as well, which is why many portable models now use propane.