Commercial Gas Testing and Purging Certificate (CP16)
Gas tightness testing and purging certificates for new or modified commercial pipework. Compliant with IGEM/UP/1A standards.
Officially RegisteredWhat is a CP16 Certificate?
The CP16 certificate is required whenever commercial gas pipework is installed, modified, or extended. It confirms the pipework has been tested for gas tightness and properly purged of air before gas is introduced.
The CP16 certificate is required for the testing and purging of commercial gas pipework.
This includes testing new pipework installations for soundness and purging gas pipes to remove air before putting them into service.
All testing is carried out in accordance with IGEM/UP/1A and relevant British Standards.
The test involves pressurising the pipework and monitoring for any pressure drop that would indicate a leak.
Why Do You Need a CP16 Certificate?
New or modified gas pipework must be proven gas-tight before any appliances are connected. This prevents gas leaks which could lead to explosions, fires, or carbon monoxide poisoning.
📋 Legal Requirement
Testing and purging must comply with IGE/UP/1A (now IGEM/UP/1A) and the Pipelines Safety Regulations. Only Gas Safe registered engineers can carry out this work.
🔄 How Often?
Required each time new pipework is installed or existing pipework is modified. Also required if pipework has been disconnected for any reason.
Gas Appliances Covered & Required Qualifications
Each appliance type requires the engineer to hold a specific ACS (Accredited Certification Scheme) qualification on their Gas Safe registration. Our engineers hold all of the qualifications listed below.
| Appliance | Gas Safe Qualification Required |
|---|---|
| Steel pipework (medium/low pressure) | COCN1 + TPCP1A (Testing & Purging ≤1m³) |
| Copper pipework (commercial installation) | COCN1 + TPCP1A (Testing & Purging ≤1m³) |
| Large-bore pipework systems (>1m³) | COCN1 + TPCP1 (Testing & Purging >1m³) |
| CSST (Corrugated Stainless Steel Tubing) | COCN1 + ICPN1 + CSST manufacturer training |
| Commercial gas pipework installation | COCN1 + ICPN1 (Commercial Pipework & Fittings) |
| Emergency control valve (ECV) | COCN1 + ICPN1 (Commercial Pipework & Fittings) |
| Isolation valves and servicing valves | COCN1 + ICPN1 (Commercial Pipework & Fittings) |
| Gas governor / regulator | COCN1 + ICPN1 (Commercial Pipework & Fittings) |
Who Needs This Certificate?
⚠️ What Happens Without a Valid CP16?
Operating without a valid gas safety certificate puts your business, staff, and customers at serious risk:
- ✗Gas leak resulting in explosion or fire risk
- ✗Carbon monoxide poisoning
- ✗HSE prosecution and enforcement
- ✗Premises closure by local authority
CP16 Inspection Checklist
Every item below is verified by our Gas Safe registered engineer during the inspection:
Visual inspection of all new/modified pipework
Check pipe supports, clips, and protection sleeves
Verify pipe material and jointing methods are compliant
Carry out strength test (e.g., at 1 bar for 1 minute)
Carry out tightness test (e.g., at 21 mbar for 2 minutes)
Monitor pressure gauge for any drop indicating leaks
Purge air from the pipework safely
Test for gas at all joints using leak detection fluid
Verify emergency control valve operation
Complete and issue CP16 test and purge record
Our Gas Safety Inspection Process
Thorough Visual Assessment
Our engineer examines every gas appliance, pipe run, and fitting for wear, corrosion, or non-compliant installation before any testing begins.
Pipework Integrity Testing
We pressurise the gas pipework downstream of the meter and monitor for any drop, confirming no leaks exist within your installation.
Flue & Ventilation Checks
We verify that all flues draw correctly and combustion gases are safely evacuated, protecting your premises from carbon monoxide build-up.
Combustion Performance Analysis
Using calibrated flue-gas analysers, we measure CO, CO₂, and O₂ concentrations to confirm each appliance burns efficiently and within safe limits.
On-the-Spot Certification
Once every check passes, your Gas Safe registered engineer issues the relevant certificate immediately — no waiting, no follow-up visits.
Scope of the Inspection — From the Meter Onwards
Downstream of the Gas Meter Only
By regulation, our engineers inspect and test the gas installation from the outlet of the gas meter onwards. Everything upstream — the service pipe and the meter itself — falls under the gas transporter's responsibility.
Included in the inspection:
- ✓ All internal gas pipework from the meter to each appliance
- ✓ Every connected gas appliance (boilers, cookers, heaters, etc.)
- ✓ Isolation valves and emergency controls
- ✓ Flue systems, ventilation openings, and extraction
- ✓ Operating pressure at each appliance
Not included:
- ✗ The incoming supply pipe before the meter (gas transporter's asset)
- ✗ The gas meter itself (owned by your gas supplier)
- ✗ Any leak or fault on the supply side of the meter
Suspect a gas leak before the meter? Call the National Gas Emergency Service on 0800 111 999 immediately — it is free and available 24/7.
Understanding Inspection Outcomes
Every appliance inspected receives one of three classifications. Knowing what each means helps you respond quickly and keep your business running safely.
Satisfactory
The appliance meets all current standards and is safe to operate. Simply schedule your next annual check and continue trading with confidence.
At Risk (AR)
The appliance falls short of current standards but poses no immediate threat to life. Continued use is at the responsible person's discretion while remedial work is arranged promptly.
- • Ventilation below recommended levels
- • Minor flue joint deterioration
- • Overdue servicing or worn seals
- • Damaged flame supervision device
Immediately Dangerous (ID)
The appliance poses an immediate risk to life. The engineer must disconnect and isolate it on the spot. Reconnection is only permitted after a qualified repair and a fresh safety inspection.
- • Active gas leak detected
- • Blocked or severed flue
- • Dangerously high CO readings
- • Flame failure device bypassed
- • Critical ventilation deficiency
Warning Notices Explained
When a fault is identified, the engineer records it formally. Here is what each notice type means for you and your premises:
At Risk Notice
Issued when an appliance does not fully conform to current standards yet is not life-threatening. The responsible person — landlord, manager, or business owner — is informed and should arrange repairs without delay.
Practical impact: The appliance may remain in use at your own risk while repairs are scheduled. However, if you decline to act, the engineer can escalate the classification to Immediately Dangerous.
Immediately Dangerous Notice
Issued when there is a direct and immediate risk to life. The engineer disconnects and caps the gas supply to the appliance without exception.
Practical impact: The appliance is labelled "DO NOT USE" and cannot be reconnected until a Gas Safe registered engineer completes repairs, confirms safe operation, and issues a new safety record.
CP16 Certificate Pricing
Prices start from £150 + VAT for 1 gas appliance. Additional appliances are charged at £25 + VAT each.
£150
1 appliance
£175
2 appliances
£200
3 appliances
£225
4 appliances
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CP16 Certificate FAQs
What is a CP16 certificate?
Commercial Gas Testing and Purging Certificate (CP16) — issued by a Gas Safe registered commercial engineer after the appliances, pipework and ventilation covered by the certificate have been inspected and tested.
How much does a CP16 certificate cost?
Pricing starts at £150 + VAT for the first appliance, with £25 + VAT for each additional appliance inspected on the same visit. You get a fixed written quote before we attend — call 07427 826446.
How long is a CP16 certificate valid for?
Twelve months from the date of inspection. We send a renewal reminder before it expires so your premises never trades without valid documentation.
How quickly can you issue the certificate?
Same-day and next-day appointments are available seven days a week, and the certificate is issued by email on the day of the inspection once the installation passes.
Ready to Book Your CP16 Certificate?
Secure your certificate today. Our Gas Safe registered engineers are available seven days a week with same-day service as standard.
Starting from £150 + VAT for 1 appliance • Same-day service available