76:0 Medium

Viessmann 76:0 Fault Code

Also written as 760 — same fault.

The Viessmann 76:0 fault code means: your boiler's internal communication system has stopped talking to a network expansion module, which may affect how advanced heating zones or external controls are managed.. It appears on 5 Viessmann models in our database.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: Without LON communication module

What causes the Viessmann 76:0 fault?

This fault occurs when the boiler's main control center loses touch with the specialized communication module that talks to your smart thermostats or external heating components. The most common reason is a loose internal connection cable or a hardware failure within the communication module itself, preventing the system from synchronizing your heating demands.

Typical repair cost £120-350 (including labour)

Engineer required

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

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Viessmann models that show the 76:0 fault code

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

Source

Viessmann 76:0 fault code information on this page is sourced and cross-checked against the official Viessmann service / installation manuals for each affected model.

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