How we verify fault codes
Where the facts come from, which source wins when two disagree, and what has to happen before we call a fault safe to look at yourself.
Last updated
The order of authority
When two sources disagree, we go with whichever is higher on this list, and we say on the page if the answer differs between model generations.
- Manufacturer technical and service documentation.
- Manufacturer support portals and published service bulletins.
- Trade body guidance — Gas Safe Register and the HHIC.
- Interviews with engineers who work on these appliances daily.
- Moderated reports from owners who have had the fault.
Owner reports never set a severity rating or a safety instruction on their own. They are useful evidence about how often something happens and what a repair actually cost, and that is how we use them.
Facts, not wording
A fact about what a code means is not copyrightable; a manufacturer's expression of that fact is. So we read the documentation to establish the fact and then write our own explanation from scratch. We do not reproduce manufacturer code tables, we do not copy sentences, and we do not host their PDFs.
Each page records internally which source types were used. Those types are disclosed publicly at the foot of the page. We do not publish scraped source URLs, because a link to a document we do not control is a broken link waiting to happen and implies an endorsement that does not exist.
Safety defaults
Any code that touches gas combustion, the flue, carbon monoxide, or an electrical fault inside a sealed unit is rated "stop — call an engineer" by default. That default can only be lowered by a qualified reviewer, and the change is logged against their name.
Pages at that rating never show do-it-yourself steps and never carry how-to structured data, because telling a search engine there is a home procedure for a gas fault we have just told you not to touch would be both wrong and dangerous.
Review cadence
Anything rated "get it checked" or "stop — call an engineer" is re-reviewed at least every 18 months. The date it was last checked is shown on the page. If that date has slipped, the page is pulled from the index until it is reviewed again.