High Lockout
E 05 on Vokera Hydra

Your boiler's internal computer is experiencing a communication error and cannot safely operate the system.

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

Internal fault (PCB)

What causes this fault?

This fault occurs when the boiler's main control board experiences an internal communication failure or a malfunction in its electronic circuitry. The most common reason is general component fatigue over time, though it can also be triggered by a sudden electrical power surge that damages the board's sensitive processors.

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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