How old is my boiler? Serial number age check by brand

Every engineer gets asked it, usually while the analyser is still going back in its bag. The age of a boiler decides whether a repair is chargeable and whether the parts are still made, so it is rarely an idle question. The answer is normally in the serial number on the data plate, but only some makers publish the rule for reading it. This page gathers what each of them does publish, and sets out the other routes to a date for the ones that do not.

How do I find out how old my boiler is?

Read the serial number off the data plate, then check whether that maker publishes a decode. Worcester Bosch, Vaillant and Glow-worm all do, and their rules are in the table below, so a build date comes straight off the badge. Baxi and Ideal publish none, and both will read the number for you if you ring them with it. Whichever make you are stood in front of, what the serial gives you is a build date rather than an installation date, and the two can be the better part of a year apart. For when the appliance actually went on the wall, the Benchmark logbook and the installer's Building Regulations notification are the documents that know.

Where is the serial number on my boiler?

On the data plate, and where that plate sits is a per-range answer rather than a per-make one. One line each below, with the full per-range detail in the brand posts linked underneath.

• Worcester Bosch. Centrally on the bottom of a Greenstar 2000 or 4000, in line with the control panel. On the frame of the front cover of an 8000 Life or Style. On the fascia of a CDi, Si, Ri or i.
• Vaillant. A plastic serial plate at the front of the appliance, with the data plate fitted to the underside at the factory. The current ecoTEC plus moves both: the serial sits under the front panel and the main data plate behind the electronics box.
• Glow-worm. Underneath on an Energy7, Ultimate 3, Easicom 3, Betacom 4 or Essential, so you read it from below with a torch. On the upper side and the rear of the electronics box on a Compact or MicraCom.
• Baxi. Behind the drop-down panel on the front, or on a tag that slides out from underneath. The plate itself is above the controls on an 800 Combi 2 and on the top part of the boiler on an 800 System 2.
• Ideal. A barcoded sticker at the top of the boiler, and on the Benchmark certificate the installer completed when it was fitted.
• Viessmann. On top of the boiler on a Vitodens 050-W, 100-W Heat Only or 200-W, and behind the front panel on the 100-W combi and the 111-W, by Viessmann's own serial number locator.
• Vokera. On the appliance data badge, which also carries the date of manufacture. Vokera does not publish where the badge is fitted, so look underneath first.

How do I read the manufacture date from the serial number, by brand?

Five of the seven makes below give you something to read on site, and no two of them work the same way, so read the row for the appliance in front of you rather than carrying a rule across from the last job. Every rule here is the manufacturer's own, taken from its manuals or its published support pages. Where a maker publishes nothing, the row says so instead of offering a guess, because a wrong build date is worse than no build date when a warranty claim rests on it.

Two cautions travel with that table. Worcester's year is a single digit, so it repeats every ten years and an FD starting 6 could be 2006 or 2016; use the range's production years to place the decade, because a Greenstar 4000 badge cannot be from 2006. And a decoded date is a build date, which is the earliest the appliance can be rather than the day it was fitted. A boiler can sit in a merchant's warehouse for months, so treat it as a floor and go to the paperwork for the rest.

The makes not in that table are absent on purpose. Potterton, Main, Alpha and Ferroli were all checked, and none of them publishes a digit by digit rule on its UK site or in the manuals we could reach. For those, the routes in the next section are the answer, starting with the Benchmark logbook and the maker's helpline with the serial number.

What if the serial does not give a date?

Then you go to the paperwork, and there is more of it than most people expect. These are the routes worth trying, roughly in the order they tend to pay off.

Why does the age of a boiler matter?

Because four practical things hang off it, and all four come up on a normal working day.

• Guarantee. Cover is tied to the installation date and to an annual service, and the length varies by range. Worcester's guarantee checker is explicit that the date it returns only holds if the boiler has been serviced every year since it was installed. Baxi's warranty terms cut cover to 12 months from the installation date recorded on the Benchmark checklist where the registration, Benchmark and annual service conditions are not met.
• Parts. A model that came out of production a decade ago is a different quoting conversation from one still on the shelf, and the PCDB's production dates are the quickest way to see which of the two you are in.
• Efficiency and controls. Boiler Plus set minimum requirements for what goes in alongside a replacement gas boiler in England, so an ageing appliance and its controls tend to get assessed together rather than separately. The Boiler Plus guide linked below covers what has to be fitted.
• A landlord's record. Age is not a field on a gas safety record and does not need to be. It belongs in the property's appliance history instead, next to the make, model and GC number, because that is what makes a pattern of faults readable in a year's time.

How old is too old?

There is no legal age limit on a domestic gas boiler. Nothing retires an appliance on a birthday, and an old boiler that is sound and burning correctly is not a defect. What engineers actually weigh is a handful of practical questions: whether it still passes its checks, whether the parts are still available, how often it has needed them lately, and what it costs to run against what a replacement would cost to fit. Worcester Bosch's published answer to how long a boiler should last is that a good quality boiler which is well maintained and professionally serviced every year should last between 10 and 15 years, and it names repairs getting more frequent and parts getting harder to find as the signs worth watching. Take that as one manufacturer's view rather than a rule, because condition beats age on nearly every appliance you will meet.

Can the CP12 tell me the age?

No. A Landlord Gas Safety Record carries the appliance details, the checks done and the results, and it has no age or installation date field on it. What it does give you is the appliance identified properly: make, model, location and, where the engineer has written them, the GC number and the serial. That is enough to take to the manufacturer's helpline or the PCDB. A run of records over several years will also show when an appliance first appeared at the property, which brackets the answer even though it does not date the boiler. For the date itself it is the Benchmark logbook or the Building Regulations notification you want.

Reading the badge is the fiddly part of the visit, and it is where a mistyped serial turns into a wasted call to a technical line. Manifold's PlateScan reads the make, model and GC number off the data plate with your phone camera and drops them straight into the record, and the appliance history stays with the property, so next year's visit starts from the right unit with last year's readings already alongside it.