When you have a new boiler fitted, you get handed a folder. Somewhere in it is a manual, and near the back of that manual are a couple of pages of boxes and signatures.
That’s your Benchmark certificate. Most people put it in a drawer and never think about it again — right up until they need to make a warranty claim, or sell the house, and suddenly it’s the most important document they own.
Here’s what it is, why it matters far more than it looks, and what to do if yours has gone missing.
What is a Benchmark certificate?
Benchmark is a national scheme run by the Heating and Hotwater Industry Council (HHIC), backed by the boiler manufacturers themselves. It applies in England and Wales and covers gas boilers, hot water cylinders, water treatment products and solar thermal systems.
The certificate — properly called the Benchmark Checklist — is a standard commissioning record. Your installer fills it in at the end of the job to record that the boiler was installed and set up correctly, to the manufacturer’s instructions, and that everything was tested and working before they left.
It’s usually printed in the back of the boiler manual, though many manufacturers now offer a digital version completed through an app, in which case you’ll get an emailed copy instead of a handwritten one. Either is fine. What matters is that it exists and it’s properly filled in.
What’s actually recorded on it?
More than most people realise. Depending on the appliance, a Benchmark checklist typically captures:
- The boiler make, model and serial number, and the date of installation
- The gas rate and burner operating pressure, measured and written down
- Flue gas analysis readings — the CO and CO₂ figures that prove the boiler is burning safely and efficiently
- Whether the system was cleaned and flushed, what inhibitor was added, and whether a filter or scale reducer was fitted
- What heating controls were installed, and confirmation the system was balanced
- Confirmation that the installer demonstrated the boiler to you and handed over the manuals
- The installer’s Gas Safe registration number, their signature, and your signature
That last one is the part people skip past. Your signature isn’t red tape — it’s you confirming that the handover actually happened. Read what you’re signing, and if the boiler hasn’t been explained to you, say so before you sign.
Why does it matter so much? Your warranty
Here’s the crucial point: a Benchmark certificate is not a legal requirement. It’s a warranty requirement.
Boiler manufacturers now offer guarantees of 10 or 12 years, and they protect themselves by insisting the appliance was installed properly in the first place. Almost every major manufacturer makes a correctly completed Benchmark checklist a condition of that guarantee.
If the boiler fails in year seven and you make a claim, one of the first things the manufacturer will ask for is your Benchmark certificate. If it was never completed, or it’s blank, or it’s lost, the claim can be refused — and you’re paying for a repair you thought was covered.
Registering the warranty is a separate step, usually within 30 days of installation, and normally something the installer does for you. Worth confirming they have.
Benchmark isn’t the only paperwork — don’t get them confused
This trips a lot of homeowners up, because three different documents get muddled together. They’re not interchangeable.
The Benchmark certificate is the commissioning record, from the manufacturer’s scheme. It protects your warranty. You get it on the day.
The Building Regulations Compliance Certificate is the legal one. In England and Wales, a Gas Safe registered business must notify a new boiler installation to the local authority, usually within 30 days, and a certificate is then sent out to you. This is your proof that the installation complies with Building Regulations. Keep it — a conveyancing solicitor will ask for it when you sell.
A Gas Safety Record (CP12) is different again. It’s the annual safety check landlords are legally required to have on rented property. If you own and live in your home, you don’t need one.
Quick way to remember it: Benchmark protects your warranty, the Compliance Certificate satisfies the law, and a CP12 is a landlord’s document.
The bit that loses people their warranty: the service record
Turn a page or two past the commissioning section and you’ll find a set of service record boxes — one for each year.
Your engineer is supposed to fill in and sign one of these at every annual service. That running history is what proves to the manufacturer that the boiler has been looked after as their terms require.
This is, in our experience, the single most common way a valid warranty quietly stops being valid. The boiler gets serviced every year, the customer pays every year, but nobody ever fills in the box. Then a fault appears in year nine, the manufacturer asks for the service history, and there’s nothing to show them.
So: get the book out when the engineer arrives. Any decent engineer will expect it. If yours is doing digital records, ask for the emailed copy and keep it somewhere you’ll find it.
What if I’ve lost mine — or never got one?
Both are more common than you’d think, especially in a house you’ve bought from someone else.
If it was completed but you’ve lost it, contact the company that installed the boiler. Many keep copies of their commissioning records, and a digital Benchmark can usually be re-sent. It’s also worth asking the manufacturer, since warranty registration may hold some of the details.
If it was never completed, it can’t be backdated — the readings were meant to be taken on the day, and no honest engineer will invent them. You may be able to demonstrate the boiler was installed correctly another way, and a full service with a proper record from here on is the sensible next step, but be aware the warranty position may already be weakened.
If you’re buying a house, ask for both the Benchmark certificate and the Building Regulations Compliance Certificate for any boiler that’s still within its guarantee. It’s an easy thing to ask before you exchange and an awkward thing to chase afterwards.
What a properly completed one looks like
Before your installer leaves, have a look at it. It should have:
- No blank boxes in the commissioning section
- Actual measured figures — gas rate, working pressure, flue gas readings — not ticks alone
- The water treatment section filled in, naming the inhibitor used
- The installer’s Gas Safe number and signature
- Your signature, added after the boiler was demonstrated to you
If it’s half empty, ask. It takes two minutes to complete properly and it’s your protection for the next decade, not theirs.
Frequently asked questions
Is a Benchmark certificate a legal requirement? No. It’s a manufacturer warranty requirement, not a legal one. The legally required document for a new boiler in England and Wales is the Building Regulations Compliance Certificate.
Who fills in the Benchmark certificate? The Gas Safe registered engineer who installed the boiler, at the point of commissioning. You sign it too, to confirm the boiler was demonstrated to you and the manuals handed over.
Do I need it if I’m selling my house? Your solicitor will generally ask for the Building Regulations Compliance Certificate. The Benchmark certificate isn’t legally required for the sale, but handing it over with a stamped service history is a genuine selling point if the boiler is still under guarantee.
Does the Benchmark certificate need updating every year? The commissioning section is a one-off. The service record pages should be completed at every annual service.
My boiler was installed years ago — is it too late? For the original commissioning record, yes. But keeping a proper service history from now on is still worth doing, and a good engineer will fill in the record each year.
Can it be done digitally? Yes, several manufacturers now support digital Benchmark completion through an app, with a copy emailed to you. It carries the same weight as the paper version.
New boiler? We’ll do the paperwork properly
Every boiler we install across Bromsgrove, Redditch, Worcester, Droitwich, Rubery, Kidderminster and Stourbridge is commissioned with a fully completed Benchmark certificate, notified to building control, and registered with the manufacturer — so your guarantee is watertight from day one.
And when we service your boiler, we’ll ask for the book. Every year.
Call Heatex Climate Solutions on 07947156905 or drop us a message for a free, no-obligation quote.
Gas Safe registered. Worcester Bosch Accredited and Baxi Approved Installers. Manufacturer guarantees of up to 12 years. Fully insured.