The short answer
A legitimate air conditioning installer should hold a recognised F-Gas qualification and work for an F-Gas-registered company, because GB law restricts all refrigerant work to certified engineers. Reputable firms are typically registered with a scheme such as REFCOM or the wider F-Gas Register, carry appropriate insurance, and notify electrical work under Part P. For air-to-air heat pumps installed under some incentives, MCS certification can also be relevant. Always verify before work begins.
Anyone can call themselves an installer, but only a certified engineer may legally handle the refrigerant inside your air conditioning. Certification is therefore your single most important check — it is the difference between a compliant, insurable installation and an illegal one. This guide explains which credentials matter, how to verify them and what else a competent firm should provide. It is general information, not an endorsement of any company.
Certification at a glance
- Core requirement F-Gas qualification + registered company
- Common scheme REFCOM / F-Gas Register
- Electrical Part P notification capability
- Heat-pump incentives MCS where relevant
- Insurance Public liability cover
- Verify Before any work starts
The non-negotiable: F-Gas certification
The single credential you must confirm is F-Gas certification. Under the GB Fluorinated Greenhouse Gases Regulations 2015, only an F-Gas-certified engineer working for an F-Gas-registered company may install, commission, service or decommission equipment containing fluorinated refrigerant. If an installer cannot demonstrate this, they cannot legally complete the refrigerant work — and an uncertified install can void manufacturer warranties, invalidate insurance and breach the law. This is not a quality nicety; it is the legal floor every other consideration sits on. For the law behind the requirement, read F-gas regulations explained.
What ‘registered’ means
There are two linked things to check: the individual engineer’s qualification and the company’s registration. Schemes such as REFCOM and the wider F-Gas Register exist so that companies handling refrigerant are registered and accountable. A registered firm has demonstrated it employs qualified engineers and follows the rules on refrigerant handling, leak prevention and record-keeping. Ask for the company’s registration details and the engineer’s qualification, and check them rather than taking a logo on a van at face value. A genuine firm will expect the question and answer it without hesitation.
The other credentials that matter
| Credential | Why it matters |
|---|---|
| F-Gas qualification | Legal requirement for refrigerant work |
| F-Gas company registration (e.g. REFCOM) | Accountable, compliant business |
| Part P / electrical competence | Notifiable electrical work done legally |
| MCS (air-to-air heat pumps) | Relevant for some incentive schemes |
| Public liability insurance | Protects you if something goes wrong |
Air conditioning installs almost always involve a dedicated electrical circuit, which is notifiable under Part P of the Building Regulations — so the firm needs to handle that compliantly too. Where the system is an air-to-air heat pump being installed under an incentive scheme, MCS certification of the installer can be relevant. For the electrical side of the job, read air con electrical requirements.
Questions to ask before you sign
- Are your engineers F-Gas certified, and is the company F-Gas registered? Can I see the details?
- Will the electrical work be notified under Part P, and will I get a certificate?
- Do you carry public liability insurance, and for how much?
- Will I get a commissioning record and a written warranty?
- Is the quote based on an actual survey of my property, not a phone estimate?
The answers tell you a great deal. A firm that surveys, certifies, insures and documents is a firm that takes the legal framework seriously — and that is the firm whose installation will still be sound and warranty-backed in five years.
What good certification gives you
A properly certified installation is legal, insurable and warranty-compliant, with refrigerant handled to standard and electrical work notified. It also means a documented commissioning record you can show a future service engineer or a buyer when you sell. The cost difference versus an uncertified fitter is small relative to the risk you carry if it goes wrong. To see how certification fits the whole job from survey to handover, read air con installation explained, and treat any quote that skips a survey or cannot evidence certification as a clear red flag.
One more point worth making is that certification protects you long after the install day. If a fault develops, an F-Gas-registered company has the qualified engineers and the recovery and charging equipment to diagnose and repair it legally, and the manufacturer will honour the warranty because the equipment was fitted to standard. An uncertified install leaves you stranded on all three counts: no lawful route to repair the refrigerant circuit, a warranty the manufacturer can decline, and an insurer who may question the work if it contributes to a claim. The certified route is not just about the first day; it underwrites the whole life of the system, which is why it should be the first thing you confirm and the last thing you compromise on.
Ask for the paperwork
Request the engineer’s F-Gas qualification and the company’s registration before work starts, alongside proof of insurance and a written commissioning and warranty record.
Frequently asked questions
What certification must an air con installer have?
At minimum, F-Gas certification for the engineer and F-Gas registration for the company, because only certified engineers may legally handle refrigerant in Great Britain. Electrical and insurance credentials also matter.
How do I check an installer is registered?
Ask for the company’s F-Gas registration (for example via REFCOM or the F-Gas Register) and the engineer’s qualification, then verify the details rather than relying on logos or claims.
Is MCS certification needed for air con?
MCS is mainly relevant for air-to-air heat pumps installed under certain incentive schemes. For a standard cooling-focused split, F-Gas certification and Part P electrical competence are the core requirements.
What happens if I use an uncertified fitter?
Refrigerant work by an uncertified person is illegal, can void the manufacturer’s warranty, may invalidate insurance and risks a poor, leak-prone installation. It is a false economy.
Sources & further reading
- gov.uk — Fluorinated Greenhouse Gases Regulations 2015 (GB F-gas)
- REFCOM — F-Gas registered companies and engineers
- MCS — Microgeneration Certification Scheme (air-to-air heat pumps)
- gov.uk — Building Regulations: Approved Document P (electrical safety)
This guide is general information, not a site-specific survey or a substitute for a quote from an F-Gas-certified installer. Installation, servicing and refrigerant handling are legally restricted to F-Gas-certified engineers.