Boiler installation certificate: what you should get and what to do if it is missing

The paperwork you should have after a new boiler

A new boiler comes with more than one document, and they are easy to confuse. Each one proves something different, so it is worth checking you have all of them before the installer's final invoice is settled.

A gas safety record is not the same thing as a Building Regulations certificate. Landlords need an annual gas safety record whatever the age of the boiler. Our guide to the gas safety record versus installation record explains the difference in more detail.

Why the certificate matters

Fitting or replacing a gas boiler is notifiable building work. Using an engineer registered with a competent person scheme, which for gas is Gas Safe Register, means you do not have to apply to building control yourself. The certificate is the evidence that this route was followed.

It matters most when you sell. The standard property information form asks about boiler installations and certificates, and a buyer's solicitor will usually want to see the compliance certificate for any boiler fitted since the rules came in. A missing certificate rarely stops a sale, but it can slow it down while you chase it. If you are on the other side of the sale, our plumbing checks before buying a house guide covers what else to ask about.

It also helps with warranties and insurance claims. Manufacturers generally want proof the boiler was fitted and commissioned by a Gas Safe registered engineer, and a completed Benchmark checklist together with the compliance certificate is the simplest way to show that. Our boiler warranty vs guarantee guide explains the conditions that usually come with a new boiler.

How long it takes to arrive

The engineer must notify the installation within 30 days of completing the work. Once Gas Safe Register has processed the notification, the certificate is posted to the address where the boiler was fitted. In most cases it arrives within a few weeks of the install.

If it has been more than a month or two and nothing has come, ask your installer to confirm the date they notified the work. Occasionally the notification is delayed, or the certificate is sent in the name of a previous occupant or to the wrong flat number in a converted building.

If your certificate is lost or never arrived

Work through these in order. Most missing certificates turn up at the first or second step.

• Check the folder that came with the boiler, and any post addressed to the property around the time of the install, including post for previous owners
• Ask the installer for the date they notified the job and the reference, if they still trade
• Contact Gas Safe Register with the address and approximate installation date to ask whether the work was notified and to request a replacement certificate; there may be a charge
• Ask your local authority building control whether they hold a record of the notification for your address
• If the work was never notified, speak to building control about regularisation, and let your solicitor know if you are selling

What if the boiler was fitted without being notified?

If the installation was never notified, the most likely explanation is that the installer did not register the job, or that the person who fitted it was not Gas Safe registered at all. The second possibility is a safety question first and a paperwork question second.

Have the boiler, flue and gas supply checked by a Gas Safe registered engineer. Illegal gas work can hide faults you cannot see, such as a flue joint that is not sealed or a boiler that was never combustion tested. If anything is found, the engineer will explain it and, where there is an immediate danger, make the appliance safe.

For the paperwork, building control can advise on a regularisation certificate for unauthorised work. When selling, solicitors sometimes deal with a missing certificate through indemnity insurance instead. That is a legal and conveyancing decision, not a plumbing one, so take your solicitor's advice on it.

If you smell gas, or a carbon monoxide alarm sounds, leave the property and call the National Gas Emergency Service on 0800 111 999. Do not wait for paperwork questions to be settled.

Getting a new boiler fitted with the paperwork in order

Loyal Plumbers handles boiler replacement across London and everywhere inside the M25, with gas work carried out by Gas Safe registered engineers. The installation is notified as the rules require, and the commissioning checklist is completed before we leave so the warranty can be registered.

If you are comparing quotes, ask each installer who notifies the work, who registers the warranty and what paperwork you will receive. Our guide to comparing boiler quotes lists the other questions worth asking. To book a survey or ask about an existing installation, call us or send an enquiry with the boiler make, rough age and what you need.