F-Gas Certification: How to Check Your Installer
Anyone who installs, services or decommissions air conditioning in the UK must hold an F-Gas qualification, and the company they work for must be F-Gas certified too. It is the law — and the quickest way to separate a professional from someone with a van and a vacuum pump. Here is what the certificates mean, how to check them in two minutes, and what a compliant handover looks like.
What the F-Gas Regulations require
Air conditioning circulates a refrigerant — today almost always R32 — which is a fluorinated greenhouse gas ("F-gas") with a global-warming potential hundreds of times that of CO₂. The UK F-Gas Regulation (retained from EU Regulation 517/2014, enforced by the Environment Agency in England with equivalents elsewhere in the UK) makes it an offence for anyone without the right qualification to install, service, repair, leak-check, recover or decommission equipment containing F-gas. Deliberately venting refrigerant is a separate offence. Businesses employing engineers for this work must hold a company certificate in their own right.
So two things are certified: the individual engineer (a personal qualification) and the company (procedures, equipment and records). A reputable installer has both and shows you both without being asked twice.
F-Gas Categories I–IV explained
| Category | What it permits | Relevant to your install? |
|---|---|---|
| Category I | All activities on any size of system: installation, servicing, leak checking, recovery, decommissioning | Yes — what an installing engineer should hold |
| Category II | Installation, servicing and recovery on systems under 3 kg of refrigerant; leak checks without breaking into the circuit | Adequate for small splits; Category I is the norm |
| Category III | Refrigerant recovery only, on small systems | No — does not permit installation |
| Category IV | Leak checking only, without breaking into the circuit | No — inspection, not installation |
Awarded by bodies such as City & Guilds (2079) and LCL Awards after assessed practical and written tests. The certificate does not expire, but company schemes require evidence of ongoing competence.
REFCOM, Quidos and Bureau Veritas
Company F-Gas certification is issued by DEFRA-approved bodies. In England and Wales the names you will most often see are REFCOM (the largest scheme, run by BESA), Quidos and Bureau Veritas; Scotland and Northern Ireland have their own approved bodies. A certified company must show it employs qualified engineers, owns proper recovery and leak-detection equipment, keeps refrigerant records and has procedures for handling and disposal. REFCOM "Elite" adds an audited quality standard above the statutory minimum. The company certificate is what makes the business legal to trade in this work — a sole trader with a personal Category I ticket still needs one in their own name. If an installer cannot name their certification body and number, that is your answer.
How to check the register
- Ask for the company's F-Gas certificate number and scheme (REFCOM, Quidos, Bureau Veritas). Any surveying engineer will know it.
- Look the company up on the scheme's public register. REFCOM publishes a searchable member directory; Quidos and Bureau Veritas verify on request. Check the trading name and address match the company quoting you.
- Ask the engineer doing the work for their personal F-Gas certificate and check the category. Subcontracted labour is common and fine, provided the subcontractor is certified too.
- Ask about manufacturer accreditation. Extended warranties from Daikin, Mitsubishi Electric and others — typically 5–7 years — depend on installation by an accredited business, which in turn requires F-Gas certification. See our brands hub.
- Check Waste Carrier registration if old equipment is being removed: recovered refrigerant and old units are controlled waste.
What goes wrong with uncertified installers
The qualification exists because the work is unforgiving. Pipework not pressure-tested with nitrogen and properly evacuated traps moisture and air in the circuit, which corrodes the compressor from the inside; the unit runs fine for a summer and fails in year three. Refrigerant "topped up" rather than leak-tested leaks out again. Flare joints made without a torque wrench weep slowly. None of it is visible on handover day. An uncertified installation can also void the manufacturer's warranty and leave you with a system a certified engineer may refuse to touch until it is brought up to standard.
Records, leak checks and the F-Gas logbook
Systems containing 5 tonnes CO₂-equivalent or more of refrigerant (roughly 7.4 kg of R32) must have periodic leak checks and records kept by the operator. Most single domestic splits sit well below that (a 3.5 kW unit typically holds under 1 kg), but multi-splits and small commercial systems can cross it, and many installers issue a simple F-Gas logbook regardless. Whatever the size, at handover you should receive a commissioning sheet recording refrigerant type and charge, pressure-test and vacuum readings and running temperatures; serial numbers; warranty registration; and the installer's company certificate details. Keep them with the house paperwork.
Questions to ask before you accept a quote
- Which F-Gas company certification scheme are you registered with, and what is your number?
- Will the engineer on the day hold a Category I certificate? Can I see it?
- Are you an accredited installer for the brand quoted, and what warranty does that give me?
- Do you nitrogen pressure-test and pull a vacuum on every installation, with the readings on the commissioning sheet?
- What public liability insurance do you carry?
- Who do I call if there is a fault in year two — you, or the manufacturer?
Every engineer Air Con Surrey matches you with is vetted and F-Gas certified as a condition of joining the network — but ask anyway; a good installer will be pleased you did. For the rest of the comparison see our guide to comparing quotes.
FAQs
Sources & methodology
- UK F-Gas Regulation (retained Regulation (EU) 517/2014 as amended) and Environment Agency guidance on certification and leak-check thresholds.
- Certification bodies: REFCOM (BESA), Quidos, Bureau Veritas; personal qualifications City & Guilds 2079 and LCL Awards.
- Refrigerant charge and CO2-equivalent figures from manufacturer data for current R32 split systems (R32 GWP 675).
Matched with vetted, F-Gas certified engineers
Air Con Surrey is a free matching service. Tell us about your property and we'll match you with local engineers who are F-Gas certified and manufacturer-accredited — then you compare their quotes.