Air conditioning is only as good as its installation. Poorly made joints leak, badly placed units are noisy, and a system that wasn’t evacuated properly can fail early. Many of the problems we’re asked to fix come from the installation, not the equipment.
This guide explains what the law requires, the other checks worth making, the warning signs and the questions to ask, so you can compare installers on more than price.
What the law requires
Two separate F-Gas requirements apply in Great Britain:
- Company certification. GOV.UK says companies, including sole traders, that install, repair, maintain or decommission air conditioning for others must be certified by an approved body. For air conditioning and heat pumps, the approved bodies listed are Refcom, F-Gas Register (Quidos) and Bureau Veritas, and certification is renewed every three years.
- Engineer qualifications. Each engineer who installs, services, leak checks or recovers refrigerant needs their own F-Gas qualification. Category 1 covers all activities; category 2 covers systems with less than 3 kg of F gas.
Ask for the company’s certificate number and which body issued it, and check it with that body.
Electrical work
Most installations need a new circuit or a connection to an existing one. That work must meet Building Regulations Part P. An installer registered with a competent person scheme, such as NICEIC, can self-certify it; the Planning Portal’s electrics page explains these schemes. Otherwise the work must be notified to building control. You should get an electrical certificate either way.
Heat pumps and grants
If you want a Boiler Upgrade Scheme grant for a heat pump, the installer must be MCS certified, and it’s the installer who applies for the grant. The scheme offers £7,500 for air-to-water heat pumps and £2,500 for air-to-air heat pumps that meet strict conditions; see GOV.UK’s grant page.
Want it done properly? AirCon Doctor installs, repairs and services air conditioning and heat pumps across London and the South East, from our base in East Grinstead. We’re an F-Gas certified company and NICEIC approved. Get a fixed-price quote.
Reviews and references
Independent review platforms such as Checkatrade show feedback from real customers. Look for a steady record over time, reviews that mention air conditioning work specifically and how the firm responds to any problems. Ask whether the firm has done similar jobs: the same kind of property, the same type of system.
Red flags
- a firm price over the phone for a job no one has seen;
- no mention of F-Gas certification, or vague answers about it;
- offering to “just regas it” without looking for a leak;
- offering to fit a DIY pre-charged kit you bought online; see DIY pre-charged kits;
- “lifetime” or long warranty promises that don’t match the manufacturer’s own terms;
- no written quote, or a quote that doesn’t say what’s included;
- no commissioning records or F-Gas paperwork at the end.
Questions to ask
- Is your company F-Gas certified, and by which body?
- Will your engineers hold F-Gas qualifications for this work?
- Who does the electrical work, and will I get a certificate?
- Will you survey before quoting, and is the quote a fixed price?
- Where will the indoor and outdoor units go, and how will pipes and condensate be routed?
- Will the system be pressure tested and evacuated, and will I get commissioning and F-Gas records?
- What warranty applies, and do I need to register the product or keep up servicing?
Our guide to what a quote should include goes further.
About AirCon Doctor
We’re based in East Grinstead and work across London and the South East. We’re an F-Gas certified company, NICEIC approved for electrical work, MCS certified for heat pumps and a Checkatrade member. Every job starts with a survey, or photos for simple jobs, then a fixed-price quote, the work itself, and commissioning with F-Gas records and a proper handover. Warranty is the manufacturer’s, and we explain each brand’s terms on the quote. See our accreditations or contact us.
Quick answers
Does an air conditioning installer need to be F-Gas certified?
Yes. Companies working on other people’s systems must be certified by an approved body, and their engineers need individual F-Gas qualifications.
How do I check an installer’s F-Gas certification?
Ask for the certificate number and the certification body, then check with that body.
Should I get a quote over the phone?
Simple jobs can be quoted from photos and details, but most need a survey for an accurate fixed price.
What paperwork should I get after installation?
Commissioning records, F-Gas records, an electrical certificate and the manufacturer’s manuals and warranty details.
Related services
More advice
- Air Conditioning Installation Cost: What the Quote Should Include
- What Happens at an Air Conditioning Site Survey
- DIY Pre-Charged Air Conditioning Kits: What the F Gas Rules Say
- Air Conditioning Warranty: What Is and Isn’t Covered
- Air Conditioning Installation: What to Expect on the Day
- All advice
This guide is general information, checked against the sources linked on 30 October 2026. It isn’t legal, tax or financial advice. Rules, grants and product ranges change, so check the current position before you rely on it.