F08 High

Ferroli F08 Fault Code

The Ferroli F08 fault code means: your boiler has sensed that parts of the internal system have become too hot, causing it to shut down automatically to prevent damage.. It appears on 4 Ferroli 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: Overtemperature protection intervention

What causes the Ferroli F08 fault?

This fault occurs when the internal temperature of the boiler rises above a safe limit, usually because water isn't moving through the system fast enough to carry heat away. The most common reasons are a failing circulation pump, a build-up of sludge or limescale blocking the heat exchanger, or a 'pocket' of air trapped within the unit.

This fault is frequently seen when the heating is first turned on after autumn, as pump components can seize up during months of inactivity.

Typical repair cost £120-350 (including labour)

DIY fix possible

Check that your radiator valves are open to allow water to circulate.Ensure there is enough water pressure in the system (typically 1.0 to 1.5 bar).Press the 'Reset' button on the control panel to see if the fault clears.

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Ferroli models that show the F08 fault code

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

Source

Ferroli F08 fault code information on this page is sourced and cross-checked against the official Ferroli service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026