8 1 High

Atmos 8 1 Fault Code

Also written as 81 — same fault.

The Atmos 8 1 fault code means: your boiler has detected that the internal fan responsible for clearing exhaust gases is not spinning at the correct speed, so it has safely shut itself down to prevent unsafe operation.. It appears on 1 Atmos model in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Fan speed incorrect
Typical repair cost £180-350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Atmos models that show the 8 1 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Atmos 8 1 fault code information on this page is sourced and cross-checked against the official Atmos service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026