Hiring the wrong engineer for your air conditioning or commercial refrigeration can cost far more than the original job. A poorly sized AC system will run all day without cooling the room properly. A rushed fridge repair can leave a slow refrigerant leak that brings the same unit down again a month later. And an engineer who is not properly certified may be breaking the law simply by opening the refrigerant circuit.
London has no shortage of companies offering cooling services, so how do you separate the reliable ones from the rest? These nine questions will help you judge an engineer or contractor before you commit, whether you run a restaurant, manage an office or are fitting air conditioning in your home.
1. Are Your Engineers F-Gas Certified?
This is the first question to ask, and the answer should be an immediate yes. Under the UK F-Gas Regulation, anyone who installs, maintains or services equipment containing fluorinated refrigerants must hold a valid F-Gas certificate, and the company itself should hold an F-Gas company certificate. That covers almost every air conditioning system and commercial fridge in use today. Ask to see the certification and check it against the relevant register if you have any doubt.
2. Do You Work on Both Air Conditioning and Refrigeration?
Many businesses run both systems. A restaurant might have split AC units in the dining room, a walk-in cold room in the back and an ice machine at the bar. Using one contractor for all of it means one point of contact, one maintenance schedule and an engineer who understands how the systems affect each other. A hot kitchen, for example, makes every fridge work harder. A firm that offers air conditioning installation, repair and maintenance in London alongside commercial refrigeration can look after the whole site.
3. Which Brands Do You Install and Repair?
Experience with the equipment you already own matters. For air conditioning, look for familiarity with major manufacturers such as Daikin, Mitsubishi Electric, Fujitsu, Samsung, LG, Panasonic and Toshiba. For commercial refrigeration, brands like Foster, Williams, Polar, Tefcold, Hoshizaki and Scotsman are common in London kitchens. An engineer who knows the brand will diagnose faults faster and is more likely to carry the right parts.
4. How Quickly Can You Respond to an Emergency?
For a business, response time is not a minor detail. When a cold room fails, every hour puts more stock at risk. Ask whether the company offers genuine 24/7 cover, including evenings and weekends, and what realistic arrival times look like in your area. Be wary of anyone who promises the impossible; a realistic window you can plan around is more useful than a vague promise. Be Cool’s commercial fridge repair team, for example, prioritises jobs by urgency and stock risk and gives a realistic arrival window when you call.
5. Do You Offer a Free Site Survey?
For any new installation, a site survey is essential. The engineer needs to measure the space, assess heat loads, check where outdoor units can go and understand how the room is used. A quote given over the phone without a visit is a guess. Reputable companies offer surveys free of charge and use them to recommend the right system rather than the most expensive one.
6. How Is Your Pricing Structured?
Ask whether there are call-out fees, how labour is charged, and whether the price quoted is the price you pay. The best contractors confirm costs before any work begins and discuss anything unexpected with you first. If a company is vague about pricing, expect surprises on the invoice.
7. Do Your Engineers Carry Common Parts?
First-visit fixes save time and money. Engineers who carry common parts and refrigerant on their vans can complete many repairs on the spot. When a part does need ordering, a good engineer will explain the delay and advise you on protecting stock or keeping the space comfortable in the meantime.
8. Will You Tell Me Honestly Whether to Repair or Replace?
Some companies push replacement because it is more profitable. A trustworthy engineer will give you an honest view. For commercial fridges, units under seven or eight years old with a straightforward fault are usually worth repairing, while older units with recurring faults or phased-out refrigerants such as R404A may be better replaced. For air conditioning, the same logic applies: age, efficiency and repair history all matter.
9. Can You Show Me References or Reviews?
Look at independent reviews, especially on Google, and ask for examples of similar projects. A company that has worked on restaurants, offices or homes like yours will understand the practical constraints, from freeholder rules on outdoor units in flats to noise limits in residential streets. Accreditations such as SafeContractor, Refcom and City & Guilds are also good signs of a professional operation.
Red Flags to Watch For
Be cautious if an engineer cannot show F-Gas certification, refuses to visit before quoting on an installation, pressures you into an immediate decision, or cannot explain the fault in plain language. Unusually low quotes can also be a warning sign, as they sometimes mean corners will be cut on pipework, electrical work or commissioning.
A Contractor That Ticks the Boxes
Be Cool Refrigeration is a London-based company that has been working on air conditioning and commercial refrigeration since 2004. It has completed more than 2,000 projects for homes and businesses, including venues such as the O2 Arena, restaurant chains and independent shops. Every engineer is F-Gas certified, pricing is transparent with no hidden call-out fees, site surveys are free, and emergency support is available 24/7 across London and the surrounding counties. The company also holds SafeContractor, Refcom and City & Guilds accreditations.
Final Thoughts
Asking the right questions takes a few minutes and can save you thousands. Check certification first, then look at experience, response times, pricing and honesty. The right engineer will welcome these questions, because they know a well-informed customer is more likely to become a long-term one.