COMCAT 1–5 are commercial catering gas appliance work categories used to define an engineer's assessed scope. They are not a ranking from beginner to expert, and holding one category does not automatically cover the others. The engineer must be Gas Safe registered and hold the category relevant to the appliance and work being performed.
COMCAT categories at a glance
| Category | Broad appliance group |
|---|---|
| COMCAT 1 | Atmospheric-burner catering appliances such as many ranges, ovens, boiling equipment, water boilers and related appliances |
| COMCAT 2 | Pressure steamers and pressure steaming ovens |
| COMCAT 3 | Deep-fat and pressure fryers, griddles, bratt pans and grill-type appliances within the category scope |
| COMCAT 4 | Commercial gas catering fish-and-chip ranges |
| COMCAT 5 | Commercial catering appliances with forced-draught gas burners |
This is a plain-English guide only. The current Gas Safe card and assessment criteria determine the exact permitted work.
COMCAT 1: atmospheric-burner appliances
The Energy & Utility Skills COMCAT1 safety assessment criteria describe the category as natural-gas and LPG atmospheric-burner appliances.
The appliance range includes many common commercial-kitchen items, including:
- open- and solid-top ranges;
- stockpot stoves and hotplates;
- warming plates and ovens;
- bain-marie units and hot cupboards;
- natural and forced-convection ovens within the category definition;
- combination ovens with atmospheric burners;
- boiling pans, urns and expansion-type water boilers;
- some gas-fired dishwashing or rinsing equipment;
- ancillary appliances within scope.
The assessment document also makes the limits visible: extract fans, ductwork, canopies, general electrical/building work and gas pipework beyond the specified appliance connection are not magically included simply because the engineer holds COMCAT 1.
COMCAT 2: pressure steam equipment
COMCAT 2 relates to pressure steamers and pressure steaming ovens. Pressure equipment presents appliance-specific hazards and service requirements that are distinct from a standard range or atmospheric oven.
Do not assume an engineer who services the rest of the cookline is qualified for a pressure steamer. Confirm the category on the current card and also check manufacturer competence where the equipment is specialist.
COMCAT 3: fryers, griddles and grills
COMCAT 3 covers appliance groups including deep-fat and pressure fryers, griddles and grill-type equipment within the defined scope. These appliances combine gas safety with high-temperature cooking, grease and significant operational wear.
The practical project lesson is to list the exact make and model. “Fryer” or “grill” in a quotation is not enough to establish the required competence or parts.
COMCAT 4: fish-and-chip ranges
COMCAT 4 is the category for commercial gas catering fish-and-chip ranges. These are often purpose-built or site-assembled systems and should not be treated as ordinary standalone fryers.
The engineer needs the correct category and sufficient product knowledge for the particular range. Ventilation, flue arrangements, controls and manufacturer instructions must also be coordinated.
COMCAT 5: forced-draught burners
COMCAT 5 covers commercial catering appliances using forced-draught gas burners. A fan actively supplies combustion air, which changes the burner and control arrangement from an atmospheric appliance.
Some large ovens, combination ovens, pizza ovens or other high-output equipment may fall within this category depending on their burner design. Do not assign the category from the appliance name alone; use manufacturer information and the engineer's confirmed scope.
Why an appliance may not fit the category you expect
Two ovens can require different competence because one uses atmospheric burners and another uses a forced-draught system. A fish-and-chip range is not simply several COMCAT 3 fryers. A pressure steamer is not covered because the engineer works on an atmospheric water boiler.
The correct sequence is:
- identify the precise appliance;
- obtain manufacturer data;
- define the work required—installation, commissioning, service, repair or disconnection;
- check the engineer's live Gas Safe registration and categories;
- confirm any manufacturer-specific requirements.
Core qualifications and fuel type still matter
COMCAT categories sit alongside core commercial catering gas competence and the fuel shown on the engineer's registration. Natural gas and LPG scopes must not be assumed to be interchangeable.
The site itself may introduce further work categories—for example, pipework, meters, controls or other commercial gas systems. The responsible Gas Safe business should identify the complete competence needed for the job.
How to check an engineer
Ask to see the front and back of the engineer's Gas Safe ID card. Check:
- the photograph and identity;
- expiry date;
- employer/business details;
- natural gas and/or LPG scope as applicable;
- commercial catering categories matching the appliance;
- any limitations on the work.
Gas Safe Register explains that commercial categories depend on factors including appliance type, pipework and gas consumption. Use its checking service if anything is unclear.
COMCAT does not cover the whole installation
A COMCAT category demonstrates gas-safety competence for work within that appliance grouping. It does not automatically qualify the engineer to design:
- the kitchen ventilation system;
- extract ductwork and fire treatment;
- odour control;
- the electrical installation;
- drainage or water treatment;
- the building's fire strategy;
- planning submissions.
A coordinated project can require several competent specialists.
Record appliance competence before booking work
The KIG 317 Commercial Kitchen Installation Guide helps owners and contractors capture the appliance, service and coordination information needed before installation and handover.
Related reading
Sources and further reading
- Energy & Utility Skills: COMCAT1 Safety Assessment Criteria, Issue 4
- Gas Safe Register: ID card categories
- Hull City Council: Gas safety information sheet with COMCAT groups
- HSE: Gas safety in catering and hospitality
Category scopes and card wording can change. Treat this as an orientation guide and check the engineer's current Gas Safe registration against the exact appliance and work. Last reviewed: 13 August 2026.