Replacement boiler installation certificate: the three documents you should end up with

Which certificate do you get after a replacement boiler in England?

A replacement boiler in England produces a building regulations compliance certificate, and that is the document most people mean by "installation certificate". It is issued through the competent person scheme the installer is registered with, not typed up by the engineer at the end of the job. GOV.UK treats the installation of a new or replacement heating appliance as notifiable work under the building regulations, even though most repairs and replacements in a home are exempt. Using a registered installer removes the need for a separate building control application. A longer walk-through of that document sits in the building regulations compliance certificate after a new boiler.

• Building regulations compliance certificate — issued through the competent person scheme. GOV.UK states it should be issued within eight weeks of the work being completed.
• Benchmark commissioning checklist — the commissioning record at the back of the boiler manual, completed and signed at handover.
• Manufacturer warranty registration — confirmation that the new appliance is registered with the maker, subject to that maker's own deadline.

A gas safety certificate is not a replacement boiler installation certificate

A landlord gas safety record proves that appliances were checked, not that a boiler replacement met the building regulations. Regulation 36 of the Gas Safety (Installation and Use) Regulations 1998, as amended, sets out what the record must contain. It lists the date of the check, the address of the premises, the landlord's name and address, a description and location of every appliance and flue checked, and the registration number of the person who did the work.

In England a landlord must give a copy to existing tenants within 28 days of the check. New tenants get a copy before they move in. The record is kept until two further checks have taken place, or for two years from the last check if the appliance has been removed. None of that tells a solicitor or a building control body that your replacement boiler was ever notified. The landlord duty is set out in landlord gas safety in England.

Benchmark commissioning checklist: the page that protects your new boiler warranty

Benchmark is the commissioning record that comes with the boiler itself, and manufacturers treat it as a warranty condition. Baxi describes Benchmark as a national scheme committing manufacturers and installers to good practice in the installation, commissioning and servicing of domestic heating and hot water products, in line with the building regulations for England. The checklist sits at the back of the appliance manual, next to the service record.

Ideal Heating states that the boiler must be installed and commissioned to the manufacturer's instructions, with every data field on the checklist completed. Your signature on the checklist confirms that the engineer explained the system and handed over the manufacturer's instructions. Ideal Heating has also moved Benchmark commissioning to an app, so after a recent replacement the record may reach you digitally rather than as a printed page. This is the document householders most often never receive, and its absence surfaces later when a warranty claim is made.

Warranty registration after a boiler replacement: deadlines differ by manufacturer

Warranty registration deadlines after a boiler replacement are set by the manufacturer, and they are not the same across brands. Vaillant requires the guarantee to be registered within 30 days of installation. Miss that window and the guarantee falls back to 12 months from the installation date. Ideal Heating and Glow-worm each run their own online registration with their own terms.

Read the terms for the boiler that was actually fitted rather than assuming one rule covers every make. Manufacturers commonly ask for three things together: a correctly completed Benchmark checklist, registration on time, and an annual service by a Gas Safe registered engineer. FM Power registers the manufacturer warranty for the customer after an installation, so ask for the registration reference alongside your paperwork.

What a replacement gas boiler has to meet in England under Boiler Plus

Boiler Plus standards have applied in England since April 2018 whenever a gas or oil boiler is replaced in an existing home. For a replacement gas boiler, the government factsheet sets a minimum ErP efficiency of 92 per cent. ErP is the energy label printed on the product. The installation must also include a boiler interlock, which stops the boiler firing when no heat is being called for, plus time and temperature control.

A replacement combi boiler needs one of four additional energy-saving measures listed in the same factsheet. These requirements sit alongside Approved Document L, the guidance on conservation of fuel and power, and a 2026 edition for use in England is published on GOV.UK. Ask the installer which Boiler Plus measure was fitted to your system and why that one was chosen. The answer belongs in the handover paperwork, not in your memory of the day.

An unvented cylinder replaced with the boiler is certified separately in England

An unvented hot water cylinder replaced alongside the boiler falls under its own part of the building regulations in England. Approved Document G3 requires an unvented hot water storage system to be installed by a competent person. It also requires safeguards against stored water rising above 100 degrees Celsius and a safe route for any discharge from the safety devices.

Unvented work is a separate qualification, and Baxi runs a dedicated G3 training course for installers. Heatrae Sadia explains that competent persons can register this work with building control themselves. Where your replacement covered both the boiler and a Megaflo or similar cylinder, expect certification for each. Who is allowed to do that work is covered in who can install an unvented hot water cylinder.

The certificate for your replacement boiler has not arrived, or you have lost it

Start with the installer if the compliance certificate for your replacement boiler has not arrived. Ask which competent person scheme registered the work, and ask for the reference the scheme holds against your address. GOV.UK states that the certificate should be issued within eight weeks of completion, which gives you a clear point to measure against.

Where no registered installer was used, or the work was never notified, GOV.UK sets out how to apply to your local building control body. Solicitors' searches raise the compliance certificate when a home is sold, so a gap usually surfaces at that stage. An EPC is a separate document: in England one must be in place before a home is marketed for sale, and it is valid for ten years. You can find an existing energy certificate or order a new one on GOV.UK.

Once the replacement is in and the paperwork is filed, the next date worth organising is the annual service, which our team handles through boiler service and repairs.

Sources

• Building regulations approval: Use a competent person scheme – GOV.UK
• Building work, replacements and repairs to your home – GOV.UK
• Gas Safety (Installation and Use) Regulations 1998, regulation 36 – legislation.gov.uk
• Check an engineer – are they Gas Safe registered? – HSE
• Benchmarking: Code of Practice – Ideal Heating
• What is the Benchmark Scheme – Baxi
• Domestic boiler guarantee terms and conditions – Vaillant
• Boiler Plus: new standards for domestic boiler installations from April 2018 – GOV.UK
• Approved Document G with 2024 amendments – GOV.UK
• Selling a home: Energy Performance Certificates – GOV.UK