D.071 Low

Vaillant D.071 Fault Code

Also written as D071 — same fault.

The Vaillant D.071 fault code means: your boiler is temporarily limiting the temperature of the water being sent to your radiators, usually because it has detected that the water is already hot enough to meet your current settings.. It appears on 7 Vaillant models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Max. heating target flow temp.

Engineer required

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

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Vaillant models that show the D.071 fault code

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

Source

Vaillant D.071 fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026