How much does it cost to fix Viessmann error code 56:0?

Typical repair cost for the Viessmann 56:0 fault is £120-250 including labour.

56:0 Low

Viessmann 56:0 Fault Code

Q: What does the Viessmann 56:0 fault code mean?

Your boiler is experiencing a communication issue with its internal hot water controls, which may limit the temperature settings available to you.

Also written as 560 — same fault.

The Viessmann 56:0 fault code means: your boiler is experiencing a communication issue with its internal hot water controls, which may limit the temperature settings available to you.. It appears on 5 Viessmann models in our database.

Technical description: DHW temperature adjustable from 10 to 60°C

What causes the Viessmann 56:0 fault?

This fault occurs when the boiler's control system loses the signal from the probe that monitors your hot water tank. The most common reason is that the internal sensor has developed a electrical fault or the wiring connecting it to the main circuit board has become loose or damaged. Without this data, the boiler cannot safely determine how much heat is needed for your taps and showers.

Typical repair cost £120-250 (including labour)

DIY fix possible

Turn the boiler power off at the main fused spur switchWait 60 secondsTurn the power back on and see if the code clears

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Viessmann models that show the 56:0 fault code

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

Source

Viessmann 56:0 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