Gas Safe - The Law
Last Updated: 18 June 2026
Gas appliances and gas installations must only be worked on by suitably qualified engineers who are registered with the Gas Safe Register.
This page provides general guidance only. For the latest legal requirements and technical guidance, please refer directly to the Gas Safe Register.
What Is Gas Safe?
The Gas Safe Register is the official gas registration body for Great Britain, Northern Ireland, the Isle of Man and Guernsey.
Gas engineers carrying out gas work must hold appropriate Gas Safe registration and qualifications for the type of appliance being worked on.
Visit the Gas Safe Register
What Is Considered Gas Work?
Gas work includes activities such as installing, servicing, maintaining, repairing, adjusting, disconnecting, altering or removing gas appliances and gas fittings.
The legal definition of gas work is broad and other activities may also fall within the scope of gas safety legislation.
Only suitably qualified Gas Safe registered engineers should undertake gas work.
What Can Homeowners Do?
Homeowners may carry out tasks specifically identified within the appliance user instructions as being suitable for the user.
Examples may include:
- Adjusting user controls.
- Programming heating schedules.
- Topping up system pressure where instructed by the manufacturer.
- Replacing user-operable components designed for customer replacement.
You should never interfere with gas carrying components, combustion components or appliance safety devices.
Can Other Trades Work on a Boiler?
In certain circumstances, non-gas components such as pumps, valves or electrical controls may be replaced by a competent tradesperson, provided the work does not involve disturbing gas carrying components or combustion seals.
If there is any doubt, the work should be referred to a Gas Safe registered engineer.
Can I Remove the Boiler Case?
Some boiler casings are purely decorative, while others form part of the combustion circuit and safety system.
Removing a decorative cover may be permitted. However, removing a case that forms part of the combustion chamber or appliance safety arrangement should only be carried out by a Gas Safe registered engineer.
If you are unsure, always refer to the appliance instructions or contact the manufacturer before removing any casing.
Finding a Gas Safe Engineer
Before allowing anyone to work on your gas appliance, always check that they are registered with the Gas Safe Register and hold the appropriate qualifications for the appliance concerned.
Find a Gas Safe Engineer
Gas Safe Register Helpline: 0800 408 5500
Important Notice
Viessmann Direct is an independent merchant supplying genuine OEM Viessmann products, spare parts and accessories.
We do not provide gas installation, servicing or commissioning services. Customers should always use appropriately qualified professionals for gas work.