If your site burns gas for cooking or heating, you need a valid commercial gas safety certificate — and probably more than one. This guide explains the two certificates hospitality operators most often need, what the inspection involves, and what to do when something goes wrong.
Who needs a commercial certificate?
Any non-domestic premises with gas appliances: hotels, restaurants, pubs, care homes, schools, offices with gas boilers. Domestic certificates (CP12) do not cover commercial appliances, and an engineer needs specific commercial categories on their Gas Safe registration to inspect them.
CP42 — Commercial Catering Gas Safety Certificate
Covers the kitchen: ranges, ovens, fryers, chargrills, salamanders and the gas supply feeding them. The engineer checks:
- Appliance operation, burner pressures and flame picture
- Gas interlock with the extract and make-up air system (required by BS 6173 and IGEM/UP/19)
- Extract canopy and ventilation adequacy
- Emergency control valve (ECV) accessibility and labelling
- Tightness test of the kitchen installation
- Flue and combustion where applicable
CP17 — Non-Domestic Gas Safety Certificate
Covers heating and hot-water plant: boilers, water heaters, warm-air units and the pipework to them. Checks include combustion analysis, flue integrity, controls, ventilation to the plant room and a tightness test of the installation.
How often?
Annually for both. Insurers and landlords frequently ask for the certificate at renewal, and Environmental Health Officers may ask during inspections.
What a gas leak looks like in practice
When a smell of gas is reported, the gas network operator (Cadent, SGN, and others) attends and will isolate the supply if a leak is confirmed — often for the whole building, not just the affected area. Trading stops until a Gas Safe engineer locates the leak, isolates or repairs it and re-tests the installation.
The fastest recovery comes from sectional isolation: separating the faulty section so unaffected plant (for example a hotel boiler house) can be safely recommissioned while the repair to the kitchen main is planned. That is exactly what allowed a Premier Inn to keep hot water while its Beefeater kitchen main was replaced.
Common failure points we find
- Buried steel mains in screed without protection — corrosion leads to leaks that are hard to locate.
- Interlocks bypassed by kitchen staff when extract fails.
- Damaged flexible hoses behind mobile appliances.
- Undersized or blocked ventilation to plant rooms.
Keeping certificates findable
Auditors want the current certificate, the previous one, and evidence that any defects were actioned. Storing them against the asset in a compliance library — as our engineers do in AiMS — means the answer is one click, not a search through inboxes. See our planned maintenance and compliance service.
Frequently asked questions
- Is a commercial gas safety certificate a legal requirement?
- Yes. The Gas Safety (Installation and Use) Regulations 1998 require employers and landlords to keep gas appliances, flues and pipework in a safe condition. An annual inspection and certificate by a Gas Safe registered engineer with the correct commercial categories is the accepted way to evidence this.
- What is the difference between CP42 and CP17?
- CP42 is the Commercial Catering Gas Safety Certificate for kitchens — cookers, fryers, ranges, interlock and extract. CP17 is the Non-Domestic Gas Safety Certificate for heating and hot-water plant such as boilers and water heaters. Many hospitality sites need both.
- How long does a commercial gas inspection take?
- A typical hotel plant room or restaurant kitchen takes two to four hours, depending on the number of appliances and whether a tightness test of the whole installation is required. Kitchens are usually inspected before service or on a closed day.