High Lockout
09 on Vokera Mynute 28E / 35E

Your boiler's internal computer has developed a fault and can no longer control the heating system correctly.

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

PCB fault.

What causes this fault?

This fault occurs when the boiler's main control board suffers an internal electronic failure or a loss of communication between its components. It is often caused by standard wear and tear over time, or a sudden electrical surge that damages the sensitive circuitry required to manage the heating cycle.

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.

Find a Gas Safe engineer
Search the official register →

Related fault codes

01View →08View →

Related guides you might find useful

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →