F8 High

Heatline F8 Fault Code

The Heatline F8 fault code means: your boiler has detected that the internal fan responsible for venting exhaust gases is not spinning at the required speed, so it has safely shut itself down to prevent unsafe operation.. It appears on 6 Heatline models 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 out of set range
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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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 7 July 2026