BoilerFaultCodesAtmos 4 Fault Code
The Atmos 4 fault code means: your boiler has tried to light itself four times but failed to create a flame, causing the system to shut down for safety.. It appears on 4 Atmos models in our database.
Technical description: No flame signal after 4 ignition attempts (lockout) — gas tap closed; incorrect ignition distance; gas inlet pressure too low or disappears; gas valve or ignition unit not receiving voltage; condensate discharge blocked; gas valve set incorrectly. See TDS012 on atmos-i.co.uk for extended diagnostic.
DIY fix possible
Check that your gas emergency control valve (gas tap) is fully open.If you have a pre-payment meter, ensure you have sufficient credit.Check if other gas appliances, like a hob, are working to confirm gas supply.Look for any frozen or blocked external condensate pipes and thaw them with warm water.
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Atmos models that show the 4 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Atmos 4 fault code information on this page is sourced and cross-checked against the official Atmos service / installation manuals for each affected model.
- Atmos Intercombi HE32 manual (PDF)
- Atmos Interopen HE22 manual (PDF)
- Atmos Intersystem HE26 manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026