High Lockout
F0290 on Worcester Bosch GB162

Your boiler's main computer brain or internal identity module has suffered a critical failure and cannot communicate 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

The burner control unit, or KIM, is faulty

What causes this fault?

This fault occurs when the boiler's internal computer chips suffer a physical electronic failure or a communication breakdown. The most common reason is age-related wear on the circuit board's components or a corrupted memory module that prevents the boiler from recognising its own identity and safety settings.

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

200View →201View →

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 →