Glow-worm data plate: where the serial number and GC number are

On a Glow-worm boiler the serial number and the GC number sit together on one identification plate, fitted to the underside of the appliance at the factory. Get a light under the boiler and read them straight off the plate before you fill in the record, rather than working from the customer's description of what is on the wall.

Where is the serial number on a Glow-worm boiler?

On the identification plate on the underside of the product. Glow-worm's own operating instructions for the Energy range put the serial number there, printed as a barcode on the plate mounted to the bottom face of the boiler at the factory. On a wall-hung Energy or Betacom4 that means reading it from below rather than from the front. Glow-worm's customer-facing guidance adds that the serial number is usually underneath the boiler or on the control panel, so on some appliances you can also bring it up on the display. A magnetic card of brief operating instructions carrying the type designation and serial number ships with the boiler too, and the number should be written in the Benchmark logbook if the original installer filled one in.

What do the digits in a Glow-worm serial number mean?

They encode the build date and the article number. Glow-worm's manual sets out the positions on the identification plate: the third and fourth digits give the year of production, the fifth and sixth give the week, the seventh to sixteenth give the product article number, and the seventeenth to twentieth record the place of manufacture. That build date is the honest way to answer how old the boiler is when the customer has lost the paperwork. Glow-worm is part of the Vaillant Group, so the plate layout and the digit positions follow the same pattern you will have seen on a Vaillant. Note the full serial as found rather than shortening it, since the whole string is what Glow-worm or a parts desk will ask for.

Where is the data plate and the GC number?

On the same underside identification plate. Unlike some brands that split the serial and the data across two labels, Glow-worm carries both on one plate under the boiler. Alongside the serial barcode it lists the gas category and connection pressure, the unit category, the efficiency class, the permissible flue connections, the maximum water pressures, the electrical rating, the heat output and load ranges, the maximum flow temperature, the NOx class, the DSN code 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 Energy or Betacom4 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 plate without wasting the visit

What to copy onto the record

• Make and model as written on the identification plate, not as described by the customer.
• GC number in full, including the dashes, so the variant is unambiguous.
• Serial number in full off the underside plate, which also fixes the year and week of build.
• 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 previous record, noted as found.

Whichever Glow-worm 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 identification plate with PlateScan, and keeps the property's appliance history ready for the next visit.