Immediately Dangerous or At Risk: what these classifications mean
When a gas appliance or installation fails to meet safety requirements, it is classified using standard terms that determine what happens next, not left to individual judgement.

How we read the ID and AR classifications on site
Immediately Dangerous means there is a risk to life right now, and the engineer must disconnect the appliance or isolate the supply before leaving, with the customer's agreement recorded. At Risk means a fault exists that could become dangerous under certain conditions but is not immediately life-threatening, and the appliance may be left connected with the customer's informed consent while repairs are arranged, provided that consent is properly recorded.
Relevant registrations
- Gas Safe registered for domestic gas boiler work
- OFTEC registered for oil boiler work
- Worcester Bosch Accredited Installer
The ID and AR classifications: engineer's shortlist
- Immediately Dangerous requires the appliance to be disconnected or isolated at the visit
- At Risk allows continued use with informed customer consent, pending repair
- Classification is based on defined criteria, not individual preference
- Customer consent for an At Risk appliance should be properly recorded
- Both classifications require the fault to be addressed, not just noted
Questions we get asked
- Can I refuse to have an appliance disconnected?
- If it is classified as Immediately Dangerous, the engineer must take action to prevent its use; the classification exists precisely because of the level of risk.
- What should I do about an At Risk appliance?
- Arrange the necessary repair as soon as practical, since the classification means a real risk exists even if it is not immediate.
Related help pages
- Oil combustion testingThe oil smoke test: what it measures and why it matters
- Service frequencyHow often a boiler actually needs servicing
- Repair or replaceWhen a boiler repair genuinely stops making sense
- Seasonal servicingWhy booking a service before winter makes practical sense
- Glow-worm fault codeGlow-worm F75: pressure sensor and pump communication fault
- Worcester fault codeWorcester A7: sealed system pressure fault on a Greenstar
Services that cover this
Where we deal with this
Get the ID and AR classifications looked at properly
In practice: These classifications are not opinions — they follow defined criteria designed to make sure genuinely dangerous appliances are not left in use.
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