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

Where is the data plate on a Viessmann boiler?

It depends on the range, and Viessmann answers it twice in two different places. Viessmann UK runs a Serial Number Locator with a page per product, and each page gives one line: the 16 digit serial number is on the top of the boiler, or it is found by taking the front panel off. The installation and service instructions answer the same question from the other end, describing the type plate itself. On every current Vitodens the LPG conversion label is fixed next to the type plate on the cover panel, and on the 111-W the manual says outright that the type plate is attached to cover panel A inside the appliance. Read the table below as the quick answer first, then the manual wording if the plate is not where you expected.

One thing worth knowing before you start unclipping panels. On every current Vitodens a second label carrying the same access code or QR code is supplied loose with the boiler, and on the 111-W Viessmann tells the installer to stick it on the outside of the appliance where the flue gas inspector can see it. If that has been done, the numbers you need are on the case and the front panel can stay put. If it has not, the loose label is often still in the document wallet on top of the boiler, because Viessmann also asks the installer to stick a copy into the installation and service instructions.

What is a GC number?

A GC number is the Gas Council number, a seven digit appliance reference written as 00-000-00 that identifies one exact appliance variant rather than a range name. Viessmann prints a Gas Council No. table near the front of most of its UK installation and service instructions, listing the number against the type code and the output. Two boilers can wear the same Vitodens badge and take different parts, and the GC number is what settles which one is on the wall. It is the identifier to write in the appliance details on a gas safety record, and our GC number hub carries the same lookup for every other make.

What is the GC number for my Viessmann Vitodens?

Look it up by the type code, the B0KA or B1KF letters, not by the marketing name. Viessmann's Gas Council No. table pairs each type and output with one number, and the list below is read straight out of the current UK manuals. B0HA is the 050-W system boiler and B0KA the combi, which the 050-W manual states directly. B1KF is the 100-W combi, B1GA the 100-W Heat Only, and B1LF the 111-W storage combi.

Two gaps in that table are worth flagging rather than filling in. The Vitodens 200-W installation and service instructions carry no Gas Council No. section at all, so on a B2HF or B2KF read the number off the type plate. The 2017 generation Vitodens 100-W, types B1HC and B1KC, prints its numbers as one undivided list on the front of the manual: 41-819-40, 41-819-41, 41-819-42, 41-819-43, 47-819-40, 47-819-41 and 47-819-42. Viessmann does not break that list down by output in that document, so take the number off the plate rather than picking the one that looks likely.

How old is my Viessmann boiler?

Viessmann publishes a key to the date of manufacture, but it decodes a seven digit code, not the 16 digit serial number. The key appears in the Vitodens 100-W Heat Only installation and service instructions and nowhere else in the current UK set, so treat it as the Viessmann rule where you can find those seven digits and use the guarantee portal or the Benchmark logbook everywhere else. Viessmann does not publish a digit by digit breakdown of the 16 digit serial, and we are not going to invent one.

How do I check a Viessmann serial number?

Put the postcode and the 16 digit serial into Viessmann's Registration and Guarantee Portal at warranty.viessmann.co.uk, which tells you whether the boiler is registered and what guarantee it carries. Viessmann UK is direct about what a blank result means: if the warranty does not show, the boiler was not registered on installation and falls under the standard two year warranty. Viessmann's own homeowner page describes the serial as the 16 digit number, found on the boiler data label on top of the boiler on the Vitodens range.

The registration deadline is the part that catches people out. For boilers installed after 31 January 2023, the installation has to be registered with Viessmann within 30 days for anything longer than the standard two years from date of delivery, and the guarantee then depends on the boiler being serviced annually by a competent, Gas Safe registered engineer with the details recorded in the Benchmark or Viessmann service logbook. The lengths below are for mainland Great Britain.

How do I read the serial number off the display?

On the Vitodens 050-W, 100-W and 111-W the serial number of the heat generator sits in the service menu under diagnostics as d.8, so you can read it without taking a panel off.

What should you copy onto the record?

• Make and model exactly as the type plate writes it, including the B0KA or B1KF type code.
• GC number in full with the dashes, from the plate or from the Gas Council No. table in that model's manual.
• The 16 digit serial number, which is what the guarantee portal and the spare parts app both work from.
• Gas category and connection pressure, so the appliance can be checked against the supply on site.
• Anything that does not match the Benchmark logbook or the last record, noted as found.

Sixteen digits read off a plate on top of a boiler in a cupboard, with a torch in your teeth, is exactly where a transposed pair slips through. Manifold's PlateScan reads the make, model and GC number off a photo of the data plate, drops them into the CP12 or service record, and keeps the appliance history against the property so the next visit opens with the right unit already filled in.