How much does it cost to fix Johnson Starley error code b24?

Typical repair cost for the Johnson Starley b24 fault is £180-350 including labour.

b24 High

Johnson Starley b24 Fault Code

Q: What does the Johnson Starley b24 fault code mean?

Your boiler's main internal computer is having trouble talking to the screen on the front, meaning the controls might not respond correctly.

Also written as B24 — same fault.

The Johnson Starley b24 fault code means: your boiler's main internal computer is having trouble talking to the screen on the front, meaning the controls might not respond correctly.. It appears on 4 Johnson Starley models in our database.

Technical description: Communication error between PCB and display panel

Typical repair cost £180-350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Johnson Starley models that show the b24 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Johnson Starley b24 fault code information on this page is sourced and cross-checked against the official Johnson Starley service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026