How much does it cost to fix Viessmann error code 04, 05, 06, 08?

Typical repair cost for the Viessmann 04, 05, 06, 08 fault is £120-350 including labour.

04, 05, 06, 08 High

Viessmann 04, 05, 06, 08 Fault Code

Q: What does the Viessmann 04, 05, 06, 08 fault code mean?

Your boiler has detected a sequence error during the ignition process and has shut down for safety to prevent a gas buildup.

Also written as 04050608 — same fault.

The Viessmann 04, 05, 06, 08 fault code means: your boiler has detected a sequence error during the ignition process and has shut down for safety to prevent a gas buildup.. It appears on 5 Viessmann models in our database.

Technical description: Burner control switches to lockout

Typical repair cost £120-350 (including labour)

DIY fix possible

Check that your gas emergency control valve is in the 'on' positionPress the reset button or turn the control knob to 'Reset' for 2 secondsVerify that other gas appliances in your home, like a hob, are working correctly

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Viessmann models that show the 04, 05, 06, 08 fault code

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

Source

Viessmann 04, 05, 06, 08 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