F-Gas Category I vs Category II UK: What Is the Difference?

Understanding F-Gas Certificate Categories

When engineers refer to F-Gas Category I or Category II certification in the UK, they are describing the scope of work covered by their qualification. The distinction is important because it determines which systems an engineer can legally work on.

Category I: Full Certification

Category I (or F-Gas Cat I) covers the full range of F-Gas activities including:

• Installation of refrigerating, air conditioning and heat pump equipment
• Maintenance and servicing of such equipment
• Leak checking
• Recovery of refrigerant
• Decommissioning

To hold Category I, engineers must pass City & Guilds 2079 or equivalent, covering both theory and practical assessment. This is the standard requirement for commercial HVAC and refrigeration engineers in the UK.

Category II: Recovery Only

Category II covers recovery of refrigerants from equipment only. It is a more limited qualification suited to engineers whose work is restricted to decommissioning or recovering refrigerant without carrying out full installation or service work.

Which Category Do You Need?

For most UK refrigeration and AC engineers — including those working with R32 heat pumps, R410A systems or R407C commercial AC — Category I certification is required. Category II is only sufficient for pure recovery-focused roles.

Browse our refrigerant gas range — all products are available to F-Gas certified engineers only.