CP42 Gas Certificate: The Ultimate Guide for UK Kitchens
Introduction
If you run a restaurant or commercial kitchen, gas safety is one of those “invisible essentials” - the kind you only think about when something goes wrong. The trouble is, when gas goes wrong, it can go very wrong. That’s where the CP42 gas certificate comes in.
This guide explains what a CP42 is, why commercial kitchens legally need one, how annual gas safety checks work, and how to stay compliant without stress. Whether you’re managing a busy restaurant or overseeing a small café kitchen, this guide covers everything you need to know to stay safe, legal, and fully certified.
And when you’re ready for your inspection? GM Service Engineering has fully qualified, Gas Safe registered engineers who carry out CP42 gas safety checks across Kent and the surrounding areas.
If your CP42 certificate is due - or you’re not sure when your last check was - get in touch with GMSE Ltd. Our Gas Safe engineers can carry out your inspection, advise on compliance, and issue your certificate quickly and professionally.
Table of Contents
1. What Is a CP42 Gas Certificate?
A CP42 gas certificate is an official document issued after a qualified Gas Safe engineer inspects and tests all gas appliances and pipework within a commercial kitchen.
This certificate confirms:
All gas appliances are safe and functioning correctly
Ventilation meets required standards
Extraction and interlock systems work properly
Pipework, valves and shut-off systems are safe
There are no gas leaks or hazards
It is the commercial equivalent of the domestic CP12, but the CP42 is specifically for commercial kitchens, restaurants, cafés and food production environments.
Why it matters
A CP42 certificate protects:
Your staff
Your customers
Your premises
Your insurance validity
Your ability to legally trade
And if you ever need to prove compliance for inspections or insurers, your CP42 is your proof.
2. Who Needs a CP42 Certificate?
You need a CP42 gas certificate if you operate any commercial kitchen that uses gas.
This includes:
Restaurants
Cafés
Pubs
Commercial catering units
School or college kitchens
Mobile catering units using LPG
Food production sites
If gas fuels any of your appliances (cookers, ovens, grills, fryers, water heaters, etc.), you need a CP42.
3. What’s Included in an Annual Gas Safety Check?
Your annual gas safety check (required for CP42 renewal) covers several key inspections.
A GMSE engineer will check:
Gas appliances
Burners, grills, ovens, fryers, and boilers
Correct flame picture
Combustion safety
Pressure settings
Heat exchange surfaces
Pipework
Visual assessment
Leak detection
Tightness testing
Ventilation
Adequate fresh air supply
No restricted airflow
Correct placement of vents
Extraction & Interlock Systems
Your extraction system must be linked to your gas supply.
If the extraction fails → the gas shuts off.
This protects the kitchen from carbon monoxide build-up.
Emergency Controls
Emergency shut-off valves
Safety signage
Access to emergency stops
After all safety checks pass, the engineer completes the certificate and issues your CP42 gas safety certificate.
4. CP42 vs CP12: What’s the Difference?
It’s easy to mix these up, but they’re very different documents.
| Certificate | Who it's for | What it covers |
|---|---|---|
| CP12 | Landlords and tenants in domestic properties. | Home boilers and domestic gas appliances in rental properties. |
| CP42 | Commercial kitchens such as restaurants, cafés, pubs and catering sites. | Commercial cookline appliances, pipework, ventilation, extraction and gas interlock systems. |
5. Is a General Appliance Service the Same as a CP42 Check?
No. A general service on your kitchen appliances is not the same as a CP42 gas safety check. This is one of the most common misunderstandings in commercial kitchens.
What a service covers
A service focuses on the performance and condition of your appliances. It may include:
Cleaning burners and components
Replacing parts
Greasing and maintenance
Checking temperatures and performance
Improving efficiency and reliability
This is essential to keep equipment running smoothly, and GMSE’s engineers carry out appliance servicing daily.
What the CP42 check covers
A CP42 inspection focuses solely on safety and compliance, including:
Gas soundness testing and pipework checks
Ventilation and airflow
Interlock systems
Emergency shut-offs
Gas appliance safety (not performance)
Ensuring your kitchen meets commercial gas regulations
Why both matter
A serviced appliance can still fail a safety check, and a gas safe appliance can still need a service.
In short:
Service = performance & maintenance
CP42 = safety & legal compliance
For full peace of mind and to stay compliant with insurers and UK regulations, most busy kitchens book both annually.
6. How to Get a CP42 Gas Certificate in the UK
Getting your CP42 is simple, but only a Gas Safe registered engineer authorised for commercial catering can issue it.
The process:
Schedule your inspection
Contact GMSE Ltd to book your annual gas safety check.A certified engineer attends your kitchen
They inspect and test all gas appliances, pipework, and extraction systems.Any issues are identified
If defects are found, the engineer will advise on repairs.Certificate issued
When everything meets safety standards, your CP42 is issued on the spot.
Quick note on LPG kitchens
If your kitchen uses LPG cylinders or tanks, the engineer will also check:
Regulators
Changeover valves
Hose condition
Cylinder storage and separation
GMSE engineers are qualified for both mains gas and LPG systems.
7. How Often Do You Need a CP42 Certificate?
A CP42 certificate is valid for 12 months.
Most insurers and local authorities require annual renewal.
Some high-risk kitchens (e.g., heavy-volume restaurants) may choose more frequent checks.
8. Common Mistakes to Avoid
A few pitfalls can cause unnecessary downtime or compliance issues.
1. Letting the certificate expire
Running a kitchen without a valid CP42 is a legal and insurance risk.
2. Confusing servicing with safety checks
A service keeps appliances efficient - the CP42 only checks safety.
3. Poor ventilation maintenance
Even safe appliances can become dangerous if airflow is restricted.
4. Using non–Gas Safe engineers
Only Gas Safe registered catering specialists can issue CP42 certificates.
5. Ignoring the extraction interlock
If your interlock fails, your gas supply should shut off - many kitchens don’t realise this.
9. FAQs
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CP42 is the official gas safety certificate for commercial kitchens. It confirms that all gas appliances, pipework, extraction and interlock systems are safe and compliant.
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No. A service cleans and maintains appliances; the CP42 check simply confirms they are safe.
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Book an inspection with a Gas Safe registered engineer. GMSE Ltd provides full CP42 gas safety checks for commercial kitchens.
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Yes. Commercial kitchens using gas must have an annual gas safety check and a valid CP42 certificate.
Conclusion
A CP42 gas certificate isn’t just a piece of paper; it’s a safeguard for your staff, customers, business and reputation. By keeping your annual gas safety check up to date, you stay compliant, insured, and protected from potentially serious gas-related hazards.
And when you’re ready to renew or arrange your first inspection, GMSE Ltd’s Gas Safe engineers are here to help. Quick, professional, and fully qualified - everything you want from the people keeping your kitchen safe.