F78 Interrupt — DHW outlet sensor not bridged on external controller

What does F78 mean?

The DHW (Domestic Hot Water) outlet sensor on an external controller UK link box is connected, but the hot water NTC is not bridged, indicating a compatibility issue with accessories.

• DHW outlet sensor on ext controller UK link box is connected but the hot water NTC is not bridged
• Accessory compatibility issue

Click steps to track your progress.

1. 1

   Check that the controls and wiring center are compatible with your boiler model.

2. 2

   Ensure the hot water NTC is correctly bridged on the external controller UK link box.

3. 3

   Consult the instructions for your external controller and link box for correct installation.