F-Gas Cat 1 Guide for UK Commercial HVAC FM Engineers 2026

Category 1 covers all refrigeration and air conditioning systems with no restriction on refrigerant charge size. Category 2 is restricted to stationary refrigeration equipment containing less than 3kg of refrigerant. In commercial FM, Cat 1 is always required — commercial HVAC systems routinely contain 10–500kg of refrigerant. Cat 2 is insufficient for any commercial site work.

The City & Guilds 2079 certificate does not have a mandatory expiry date under current UK law (SI 2015/310). There is no annual renewal requirement. However, many FM contractors apply an internal policy requiring engineers to have completed training within the last 5 years. Check your employer's specific requirements. When the regulations change significantly, providers typically offer a short update course rather than full recertification.

You can perform tasks that do not involve the refrigerant circuit — filter replacements, belt changes, coil cleaning, electrical fault-finding, controls calibration, BMS adjustments. You cannot legally open the refrigerant circuit, connect gauges to measure system pressure, add or remove refrigerant, or perform leak checks that involve system manipulation. In practice, most commercial FM HVAC roles require regular refrigerant circuit work, making Cat 1 essential.

Both written papers require 70% to pass. The practical assessment is marked as satisfactory or unsatisfactory by the assessor — there is no percentage threshold, but you must demonstrate correct technique throughout. If you fail a written paper, it can be re-sat without retaking the full course, typically for a re-sit fee of £50–£80. Failing the practical usually requires a full re-sit.

City & Guilds typically take 4–6 weeks from assessment date to issue the formal certificate. Your training provider will give you a certificate of completion or confirmation letter on the day, which most employers and contract clients accept in the interim. Do not attempt commercial refrigerant work without at least the provider confirmation letter.

City & Guilds 2079 and BPEC F-Gas are both approved UK qualifications that satisfy the requirements of SI 2015/310. They are issued by different awarding bodies but carry equal legal weight. City & Guilds is more widely held and marginally more recognised by large FM contractors, but BPEC is equally accepted. If your preferred training provider offers BPEC, it will not disadvantage you.

Cat 1 covers all F-Gas refrigerants including current common refrigerants (R-410A, R-32, R-407C, R-134a, R-404A), legacy refrigerants on older systems (R-22 — recovery only, since R-22 was banned from use in 2015), and newer low-GWP refrigerants entering the market (R-454B, R-452B, R-1234yf, R-1234ze). The certificate is not refrigerant-specific — it qualifies you to handle any F-Gas regulated substance.

Yes. All air conditioning systems contain refrigerant in a closed circuit. Servicing an air conditioning unit — even replacing filters and checking temperatures — does not require Cat 1. But as soon as you need to connect gauges, diagnose refrigerant faults, adjust charge, recover refrigerant, or perform a leak check that involves the refrigerant circuit, you need Cat 1. In commercial FM, nearly all reactive HVAC callouts will at some point require refrigerant circuit access.

Refcom (F-Gas Register) is the company registration scheme for businesses that handle F-Gas refrigerants commercially. Individual engineers hold the City & Guilds 2079 certificate. Their employer must separately register with Refcom (or the equivalent ACRIB scheme) to demonstrate the company has certified staff and proper procedures. Both are required for legal commercial work. Sole traders must register as both individual and company. Your employer should handle Refcom registration — if they haven't, raise it before starting refrigerant work.

Prices in 2026 typically range from £400–£550+VAT for a 4-day course including both written assessments and the practical. Group bookings of 4+ engineers usually attract 10–15% discounts. Some employers fund the course directly through a training agreement with a clawback clause (typically 12–24 months' employment commitment). Re-sit fees for failed papers are usually £50–£80 per paper.

Yes, and most do. F-Gas Cat 1 training is a direct business requirement for commercial HVAC contractors — it is not a discretionary benefit. Many FM contractors fund the training upfront with a training agreement requiring 12–24 months' continued employment, or fund it at the 6-month mark once the engineer has passed probation. If you are a new hire without Cat 1, negotiate training funding into your offer — it is standard practice in commercial FM.

Under SI 2015/310, operating without the required certification is a criminal offence. Enforcement is carried out by the Environment Agency (England), SEPA (Scotland), and NRW (Wales). Penalties for individuals start at £300 per incident. For companies, fines can reach £200,000 for serious violations. Beyond legal penalties, working without certification will void your employer's insurance cover and potentially invalidate the building owner's F-Gas compliance records.