DIY boiler installation: why it needs a Gas Safe registered engineer.
Fitting or replacing a boiler is gas work. Here is why it should be done by a Gas Safe registered engineer, what the rules say, and what you can safely do yourself.
The short answer
Do not fit, replace or move a gas boiler yourself. Gas work in homes should only be done by a Gas Safe registered engineer who is registered for the type of work.
This page is general information, not legal advice.
Why
- The law: the Gas Safety (Installation and Use) Regulations 1998 set out that gas work must be done by a competent person, and for work in homes that means a Gas Safe registered engineer.
- Building Regulations: in England, replacing a boiler is notifiable work. A registered engineer notifies it through their competent person scheme and you receive a compliance certificate. Without it you can have difficulty selling or insuring the home.
- Safety: poor gas work can cause gas leaks, fire and carbon monoxide poisoning. Fumes can be invisible and odourless.
- Warranty and insurance: manufacturers usually require installation and commissioning by a registered engineer, and unregistered work can affect your warranty and your home insurance.
- Landlords: a landlord must have the gas installation checked annually by a Gas Safe registered engineer, and unregistered work will not pass.
What you can do yourself
- Clear access to the boiler, meter and pipework, and take photos for a quote, without removing any covers.
- Decide what you want: like-for-like or a different type of boiler. See combi, system or regular.
- Bleed radiators and check the pressure gauge, as your boiler’s manual describes. If pressure keeps dropping, see boiler losing pressure.
- Check any engineer before you book: ask to see their Gas Safe ID card, check the types of gas work listed on the back of it, and look them up on the Gas Safe Register website.
Getting a boiler fitted properly
Start with the online boiler price for a like-for-like replacement, or ask for a free survey for anything more involved. Your written quotation names the installer, who your contract is with, and your warranty and workmanship guarantee. See boiler installation.
A two-hour arrival window can be confirmed on the day.
Smell gas? Call the National Gas Emergency Service on 0800 111 999 straight away.