High Lockout
E13 on Ravenheat CSI 85

Your boiler's internal computer has encountered a glitch or a configuration error and cannot communicate properly with 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

Software error

What causes this fault?

This fault occurs when the boiler's internal computer experiences a software conflict or a complete data failure. It is usually caused by a physical defect in the printed circuit board's memory or a sudden electrical surge that has corrupted the system's programming.

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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