Overview


A Gas Safety Certificate (CP12) is an official record confirming that gas appliances, pipework, and flues within a rental property have been inspected and deemed safe by a qualified engineer.

In the UK, inspections must be carried out by an engineer registered with the Gas Safe Register. Only engineers listed on this register are legally permitted to work on gas appliances.

The certificate is primarily a landlord legal compliance document and forms part of mandatory property safety management.


Evidence

Please see our warning notice and Gas Safety Certificate . 


Legal Framework

 

Under the Gas Safety (Installation and Use) Regulations 1998, landlords are legally responsible for ensuring gas appliances and flues are maintained in a safe condition.

Landlords must:

  • Arrange a gas safety check every 12 months

  • Use a Gas Safe registered engineer

  • Provide a copy of the certificate to tenants within 28 days of the check

  • Provide new tenants with a copy before occupation

  • Retain records for a minimum of two years

Non-compliance can result in enforcement action, fines, prosecution, imprisonment in serious cases, and invalidated insurance policies.


What the Inspection Covers


The inspection is a safety check rather than a full service. It confirms that gas installations are safe at the time of inspection.

Gas appliances checked typically include boilers, gas fires, cookers, hobs, and water heaters.


During the inspection, the engineer will assess:


Appliance Safety

  • Correct gas pressure and flow

  • Proper combustion performance

  • Operational safety devices

  • Secure appliance installation

  • Signs of unsafe wear or corrosion

Flues and Chimneys

  • Safe removal of combustion gases

  • Adequate ventilation

  • No blockages or disconnections

  • Proper sealing and support

Gas Pipework

  • Tightness testing to detect leaks

  • Soundness of installation

  • Accessibility of emergency isolation valve

Ventilation

  • Adequate air supply for safe combustion

  • Compliance with current standards 


Information Contained on a CP12


A Gas Safety Certificate will include:

  • Property address

  • Landlord or managing agent details

  • Engineer’s name and Gas Safe registration number

  • Date of inspection

  • Appliance details (make, model, location)

  • Results of checks performed

  • Any safety defects identified

  • Classification of issues (if present)

  • Required remedial actions

  • Confirmation of overall safety status


Pass and Fail Classifications


If appliances meet safety standards, the certificate confirms compliance and is valid for 12 months.

If issues are found, they are categorised as:

At Risk (AR)
An appliance has a fault that could become dangerous. It should not be used until repaired.

Immediately Dangerous (ID)
An appliance poses an immediate threat to safety. The engineer may disconnect it on the spot.

If failures occur, remedial work must be completed before compliance is restored. A new certificate or written confirmation may be required after repairs.


Validity and Renewal


A Gas Safety Certificate is valid for 12 months from the date of inspection.

Landlords are permitted to renew the certificate up to two months early while preserving the original renewal date. This helps maintain a consistent compliance cycle.


Risk and Safety Importance


Gas safety checks are critical in preventing:

  • Gas leaks

  • Carbon monoxide exposure

  • Fires

  • Explosions

  • Serious injury or death

Carbon monoxide is colourless and odourless, making it particularly dangerous without proper appliance maintenance and testing.