High Lockout
E33 on Vokera Pinnacle

Your boiler's internal computer has detected a communication error or a hardware failure within its own electronic control 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

What causes this fault?

This fault occurs when the boiler's main control board suffers a hardware failure or a breakdown in its internal communication lines. It is essentially a software crash or an electronic malfunction that prevents the boiler from safely processing instructions. The most common reason is age-related component fatigue on the circuit board or a loose connection in the internal wiring harness.

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

E37View →

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