Heatline F8 Fault Code
The Heatline F8 fault code means: your boiler has detected that the internal fan responsible for safely removing exhaust gases is not spinning at the correct speed, so it has shut down to keep your home safe.. It appears on 3 Heatline models in our database.
Technical description: Fan speed out of set range
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Heatline models that show the F8 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Heatline F8 fault code information on this page is sourced and cross-checked against the official Heatline service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026