High
F.67 on Vaillant ecoTEC plus System

Your boiler has detected an internal communication error with its flame-monitoring system, meaning it cannot safely confirm that the burner is operating, so it has shut down to prevent any risk.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Flame detector input signal is outside the limits (0 or 5 V)

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F.61View →F.62View →F.63View →

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