High Lockout
EE9 on Worcester Bosch WR325 RSF

Your boiler has detected a communication issue or a fault with one of its internal ignition electrodes, meaning it cannot safely light the burner.

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

Second electrode

What causes this fault?

This fault occurs when the boiler's control system loses contact with the secondary electrode responsible for creating the spark to light the gas. It is usually caused by the electrode becoming worn out, cracked, or covered in carbon deposits, which prevents it from sending the correct electrical signal back to the main circuit board.

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

EAView →E9View →

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 →