How much does it cost to fix Vaillant error code D.69?

Typical repair cost for the Vaillant D.69 fault is £100-350 including labour.

D.69 High

Vaillant D.69 Fault Code

Q: What does the Vaillant D.69 fault code mean?

Your boiler has failed to light the flame twice in a row, which means the system has stopped providing heating and hot water for safety.

Also written as D69 — same fault.

The Vaillant D.69 fault code means: your boiler has failed to light the flame twice in a row, which means the system has stopped providing heating and hot water for safety.. It appears on 26 Vaillant models in our database.

Technical description: Unsuccessful ignition for the second time

What causes the Vaillant D.69 fault?

This fault occurs when the boiler's control system fails to detect a flame after two consecutive attempts to start. The issue is usually caused by a lack of fuel reaching the burner, a faulty spark that cannot ignite the gas, or a sensor that is unable to confirm the flame is present.

This fault is more frequent during very cold spells when external gas regulators or pipes can experience pressure drops or ice-related blockages.

Typical repair cost £100-350 (including labour)

DIY fix possible

Check if other gas appliances, like a hob, are working to ensure gas is reaching the propertyCheck that your gas pre-payment meter (if applicable) has enough creditPress the Reset button (the flame icon with a cross) for one second to see if the boiler restarts

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Vaillant models that show the D.69 fault code

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

Source

Vaillant D.69 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 27 April 2026