How much does it cost to fix Viessmann error code d2?

Typical repair cost for the Viessmann d2 fault is £120-350 including labour.

d2 High

Viessmann d2 Fault Code

Q: What does the Viessmann d2 fault code mean?

Your boiler has switched itself off because it has reached an unsafe temperature and needs to cool down before it can be used again.

Also written as D2 — same fault.

The Viessmann d2 fault code means: your boiler has switched itself off because it has reached an unsafe temperature and needs to cool down before it can be used again.. It appears on 5 Viessmann models in our database.

Technical description: Burner fault: Temperature limiter has responded

What causes the Viessmann d2 fault?

This fault occurs when the water inside the boiler gets too hot, causing a safety sensor to trip and shut the system down to prevent damage. The most common reasons are a pump failure that stops water from moving around the system or a build-up of debris and limescale that blocks the internal pipework.

This fault is more common in autumn and winter when the heating is first turned on after a long summer break, as internal pumps can sometimes seize up from lack of use.

Typical repair cost £120-350 (including labour)

DIY fix possible

Wait 30 minutes for the boiler to cool downCheck that your radiator valves are open to allow water to flowPress the 'Reset' button on the boiler control panel

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Viessmann models that show the d2 fault code

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

Source

Viessmann d2 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