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F35 FAULT CODE
Ferroli

Incorrect Mains Frequency

Medium Severity Engineer Required

On Ferroli boilers, F35 indicates an incorrect or irregular mains power frequency (should be 50Hz in the UK).

Step-by-Step Fix Guide

  1. Step 1

    Check with an electrician that the mains supply frequency is correct

  2. Step 2 Engineer only

    If mains is correct, call a Gas Safe engineer

Gas Safe Reminder

Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.

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