How to Find a Reliable Air Conditioning or Heat Pump Installer in the UK
The certificate that legally has to exist, what a fair quote actually itemises, and the red flags worth walking away from — before you pick up the phone, not after something's gone wrong.
By KeepCoolExpert Team · Updated 31 August 2026
Most advice on finding a tradesperson is the same three words rearranged: get quotes, check reviews. That’s not wrong, but it’s not enough either — it doesn’t tell you what to actually look for once the quotes and reviews are in front of you, which is where a genuinely bad choice usually happens. This is the fuller version.
The one thing that’s actually the law, not just good practice
Anyone installing, servicing, or decommissioning a system containing F-Gas refrigerant — which covers any domestic air conditioner and most heat pumps — legally has to hold specific qualifications, and their company has to hold a REFCOM (or equivalent) F-Gas company certificate. This isn’t a “trusted trader” style accreditation you can take or leave; it’s the law, enforced with fines up to £200,000 per offence for companies that skip it.
Ask for it directly, and don’t stop there — REFCOM and equivalent schemes keep a public register of registered companies, so you can check a company actually appears on it rather than trusting a certificate photo. A legitimate installer produces this without hesitation, because they’re required to have it regardless of whether you ask. One who gets vague, changes the subject, or says they’re “sorting it out” isn’t someone to let near gas-filled equipment.
If it’s a heat pump specifically, the equivalent requirement is MCS certification — this matters even more if you’re claiming a Boiler Upgrade Scheme grant, since the installer applies for that grant on your behalf, and it can only be claimed through an MCS-certified installer who’s also a member of an approved consumer code (RECC or HIES).
What a fair quote actually looks like
Three quotes, itemised the same way, is the boring-but-correct baseline — but “itemised” is doing a lot of work in that sentence. A quote worth comparing states:
- Unit cost and labour cost as separate lines. A single lump figure makes proper comparison impossible, whether that’s deliberate or not.
- Any additional work — pipework, electrical work, making good — priced separately, not folded silently into the total.
- Whether VAT is included, and from a business that’s VAT-registered if its size requires it.
- A written form, not a verbal figure given on the doorstep. If you can’t hold it up against another quote line by line, it isn’t really comparable.
Red flags worth walking away from
Most bad experiences with tradespeople have warning signs before any money changes hands, not after:
- Pressure to sign there and then for a “today only” price
- No written, itemised quote — just a verbal number
- Vagueness or resistance when you ask for their F-Gas/REFCOM or MCS certificate
- No fixed business address you can independently verify
- Insistence on cash payment with no VAT invoice offered
Any single item here might have an innocent explanation. More than one together is a real pattern, not bad luck.
Two honest routes, not one correct answer
You can do all of the above yourself — it costs nothing but time, and it’s just as valid a route as any other. Or a vetted tradesperson platform can do some of that groundwork for you, matching you with installers who’ve already been through a vetting process, which is a genuine convenience if you’d rather not chase certificates and reviews across multiple companies. That’s not a substitute for confirming the certificate yourself once real quotes are in front of you — but it can shorten the list you’re checking in the first place.
Where this fits against everything else on this site
If you haven’t settled on a system yet, our guides to air conditioning installation costs and the air-to-air heat pump grant cover pricing and the planning-permission rules specifically — this guide is about the “who do I actually hire” step once you know what you’re having fitted.
Frequently asked questions
- How do I actually check an installer's F-Gas or REFCOM certificate is real?
- Don't just take the certificate at face value — REFCOM (and equivalent F-Gas competent person schemes) maintain their own public register of registered companies, so you can check independently rather than trusting a photo of a certificate on a van. If a company can't be found on the register they claim to belong to, that's a real problem, not an admin oversight.
- What should a fair, itemised quote actually include?
- Unit cost and labour cost as separate lines, not one lump figure — anyone bundling them is making comparison shopping harder than it needs to be, deliberately or not. It should also specify any additional pipework, electrical work, or making-good costs, state whether VAT is included, and come from a VAT-registered business if the company's turnover requires it. A verbal quote with no written breakdown isn't a quote you can actually compare against anything.
- Is it worth using a vetted platform instead of finding an installer myself?
- It genuinely can save the legwork of chasing certificates and reviews yourself, since a decent platform has already done some of that vetting — but it's a convenience, not a substitute for confirming the certificate yourself once you're comparing real quotes. Self-vetting is free and just as valid; a platform trades a bit of that effort for a fee built into how installers are matched to you.
- What red flags mean I should walk away from a quote?
- Pressure to sign on the spot for a 'today only' discount, no written itemised quote, reluctance to provide a F-Gas or REFCOM certificate when asked directly, no fixed business address you can find independently, and insisting on cash with no VAT invoice. Any one of these alone might have an innocent explanation; more than one together is a pattern worth walking away from.