For engineers

Baxi data plate: where the serial number and GC number are

By Jordan Valentine-Dunn, Gas Safe registered engineer · 23 July 2026

A Baxi combi boiler with the drop-down front panel open, showing the serial number sticker and the pull-out data tag underneath

On a Baxi the serial number is usually on the drop-down panel on the front of the boiler, and some models carry it on a tag that pulls out from underneath instead. The data plate holds the model, the gas category and the GC number. Read them off the appliance rather than the customer's description before you fill in the record.

Where is the serial number on a Baxi boiler?

On the drop-down panel on the front, or on a pull-out tag underneath. Baxi's own guidance puts the serial number on a sticker on the inside of the drop-down front panel, and notes that some boilers instead have a tag that slides out from the bottom of the case. On the current numbered ranges such as the 800 and 600 you drop the front flap and it is behind there. If the label has faded or the tag has gone, Baxi Customer Support can identify the boiler from the serial number over the phone.

What does the Baxi serial number tell you?

The make, the model and the age. Baxi says the serial number holds all the information about which boiler it is and how old it is, which is the honest way to answer the age question when the customer has lost the paperwork. Baxi does not publish an open decode table for the digits, so rather than guessing at a build date from the number, note the full serial as found and let Baxi confirm the age if it matters for a warranty claim.

Where is the data plate and the GC number?

On the appliance data plate, which carries the model designation, the gas category and connection pressure, the electrical rating and the GC number. The GC number is the Gas Council number, a seven digit appliance reference written in the form 00-000-00. It identifies the exact appliance variant rather than the marketing name, so two boilers wearing the same range badge can take different parts, and the GC number is what a merchant or parts catalogue will ask you for. It is the cleanest thing to record because it does not depend on how the customer describes their boiler.

How to read the plates without wasting the visit

Drop the front panel first

Open the drop-down flap on the front and look for the serial number sticker inside it.

Check underneath if it is not there

On models with a pull-out tag, slide the tag out from the bottom of the case to read the serial.

Read the data plate for the GC number

Take the model designation, gas category and the GC number in full off the data plate.

Photograph what you find

Shoot the serial and the data plate square on before you touch anything, so you are not going back for a second look.

Cross-check the Benchmark book

Baxi's supplied instructions carry the Benchmark checklist and service history; check the numbers against it and note any mismatch as found.

What to copy onto the record

  • Make and model as written on the data plate, not as described by the customer.
  • GC number in full, including the dashes, so the variant is unambiguous.
  • Serial number from the front panel or the pull-out tag, which also fixes the make, model and age.
  • Gas category and connection pressure, so the appliance can be checked against the supply on site.
  • Anything that does not match the Benchmark book or the previous record, noted as found.

Only a Gas Safe registered engineer can service, size, install or certify a boiler. This is general guidance on where the identification data sits. Always work to the manufacturer's current instructions for the specific model in front of you.

Boiler reference

Whichever Baxi is on the wall, the record is the same job every time. Manifold builds the CP12 and service record from the check on your phone, reads the make, model and GC number off the data plate with PlateScan, and keeps the property's appliance history ready for the next visit.

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Frequently asked

Where is the serial number on a Baxi 800 or 600?

Behind the drop-down panel on the front of the boiler, on a sticker inside the flap. Some Baxi models instead carry the serial on a tag that pulls out from underneath the case. If you cannot find it, Baxi Customer Support can identify the boiler from the serial.

What is the GC number on a Baxi boiler?

The Gas Council number, a seven digit appliance reference in the form 00-000-00 printed on the data plate. It identifies the exact appliance variant rather than the range name, which is why it is the safest thing to record and the number a parts merchant will ask for.

How can I tell how old a Baxi boiler is?

The serial number holds the make, model and age. Baxi does not publish an open decode table, so note the full serial and, if the age matters for a warranty claim, let Baxi confirm it from the number rather than guessing a build date.

What should I copy onto the CP12 from a Baxi?

The make and model as written on the data plate, the GC number in full with its dashes, the serial number, and the gas category and connection pressure. Note anything that does not match the Benchmark book as found.

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