F-Gas certification for maintenance engineers

It's a hot afternoon. The process chiller on the moulding line has tripped on low pressure for the third time this week. The tools are getting warm, the setter is twitchy, and production want to know when it'll be back.

You've got a set of gauges in the van. You can see the frost on the pipe and you've got a fair idea it's short of gas. Twenty minutes and you could know for sure.

But you haven't got an F-Gas certificate. So the gauges stay in the van, and the site waits for the refrigeration contractor.

That wait is the whole case for this ticket. If chillers, panel coolers or cold stores are part of your patch, F-Gas is the difference between fixing it and phoning someone who can.

You need your own certificate

The rule here is personal. GOV.UK says you must have your own qualifications to work on equipment containing F-gas, even if you work for someone else. It's against the law to work with F-gas without the right qualifications, and you could get a civil penalty (GOV.UK, qualifications).

That's different from most tickets. Most of the time the law asks for competence, and a site decides what proof it wants. With F-gas, the certificate itself is the requirement. Your site's say-so doesn't cover you.

Which category you need

For stationary refrigeration, air conditioning and heat pumps, the qualifications cover installing, servicing, maintaining, leak checking, recovering gas and decommissioning. There are four categories* (GOV.UK, qualifications):

1. Category 1 covers all activities.
2. Category 2 lets you install, maintain, service and recover refrigerant from systems with less than 3kg of F-gas, or less than 6kg if hermetically sealed*.
3. Category 3 lets you recover refrigerant from systems under the same limits*.
4. Category 4 lets you check equipment for leaks, as long as you don't break into the refrigeration circuit.

The qualification has to come from one of the accredited bodies on that page. City & Guilds, BESA and LCL Awards are listed, and CITB no longer issues new F-Gas qualifications or certificates*.

Here's our view. Category 1 is the one to aim for if refrigeration is a real part of your work. In our experience plenty of process chillers hold more than 3kg, so Category 2 can leave you able to work on the small kit and not the big one. Check the charge on the nameplate of the plant you actually look after before you book.

Category 4 on its own is narrow. It suits someone doing leak checks on a round, not someone fixing breakdowns.

Where it bites on a factory floor

Refrigeration hides in more places than the cold store.

• Process chillers on moulding machines, lasers and hydraulic power packs
• Panel air conditioners keeping drives cool in hot weather
• Refrigerated compressed air dryers
• Cold stores, blast freezers and chilled docks in food logistics
• Split air-con units in offices and control rooms

When any of these fail on a hot day, the line feels it fast. We cover the knock-on faults in hot weather and breakdowns, and the cold-chain side in refrigeration plant breakdowns in food logistics.

Contracting changes the picture

If you're on staff, your employer servicing its own kit doesn't need company certification. GOV.UK gives the example of a supermarket that directly employs someone to service its own refrigeration: the supermarket doesn't need certifying. But if it contracts another company to do the work, that company must be certified. Either way, the individual still needs their own qualification (GOV.UK, company certification).

Now go contract. Your company, and that includes a sole trader, must be certified by an approved body to service stationary F-gas equipment operated by others. To get certified you have to show you employ enough trained staff and have a written procedure for handling F-gas safely and keeping emissions down. Company certification has to be renewed every 3 years*.

So a fitter who's been servicing the chillers on staff for years can't carry on doing the same work as a contractor on their personal certificate alone. Sort the company side before you quote for it. If you're setting up on your own, read setting up as a sole trader engineer too.

Leak checks are the site's duty

The person who uses the equipment is responsible for getting it leak checked. How often depends on how much gas it holds, measured in tonnes of CO2 equivalent. From 5 to under 50 tonnes it's at least once every 12 months*. From 50 to under 500 tonnes it's every 6 months*. At 500 tonnes or more it's every 3 months, and an automatic leak detection system must be fitted* (GOV.UK, leak checks).

Fit automatic leak detection where it isn't required and the gap between checks can double. If a check finds a leak, it must be repaired as soon as possible and the test repeated within a month to check the repair worked*.

That matters for you because it's often the maintenance engineer who spots the oily joint or the frost in the wrong place. Know the rules, write it up, and make sure the leak gets a retest booked. Leaving it to "next service" isn't an option the guidance gives.

Don't let a shift manager talk you into it

The pressure on a hot day is real. The chiller's down, the tools are overheating, and someone says "just put a bit of gas in it".

Don't. If you don't hold the right category, you're the one doing the work without the qualification the law asks for. Isolate it, make it safe, record what you found, and get the right person in. A good write-up of the symptoms will save the refrigeration engineer half an hour when they arrive. See chiller down: protecting product while the engineer's on the way for what to do in the meantime.

One more thing if you work abroad. A UK F-Gas certificate isn't valid for work in the EU, so you'd need a recognised qualification from an EU member state*. For where F-Gas sits among your other tickets, see which tickets actually get you contract work.

What to do on Monday

1. Walk your site and list every piece of kit with a refrigeration circuit. Note the gas type and charge from each nameplate.
2. Decide if the work is regular enough to justify Category 1. If not, agree who you call.
3. If you're going contract and want to do refrigeration work, look into company certification before you take the job.
4. Next time you see a likely leak, log it and make sure the repair and retest get booked.

* F-Gas categories, charge limits, accredited bodies, the 3-year renewal, leak check intervals, the one-month retest and the EU position correct as of 10 October 2026. Check GOV.UK's F-Gas qualifications guidance and leak checking guidance for the latest.