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F78 FAULT CODE
Glow-worm

DHW Outlet Sensor Not Bridged

Medium Severity Engineer Required

The hot water NTC is not connected or bridged (when an external controller is fitted).

Step-by-Step Fix Guide

  1. Step 1 Engineer only

    A Gas Safe engineer should check the sensor connection and link box

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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