How much does it cost to fix Ferroli error code E35?

Typical repair cost for the Ferroli E35 fault is £150-300 including labour.

E35 High

Ferroli E35 Fault Code

Q: What does the Ferroli E35 fault code mean?

Your boiler is struggling to detect the power supply frequency, which is causing it to shut down to prevent damage to its internal electronics.

The Ferroli E35 fault code means: your boiler is struggling to detect the power supply frequency, which is causing it to shut down to prevent damage to its internal electronics.. It appears on 1 Ferroli model in our database.

Technical description: Mains frequency fault

Typical repair cost £150-300 (including labour)

Engineer required

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

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Ferroli models that show the E35 fault code

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

Maxima 35 S Repair: £150-300

Source

Ferroli E35 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