1.91 High

Johnson Starley 1.91 Fault Code

Also written as 191 — same fault.

The Johnson Starley 1.91 fault code means: your heating system has encountered a communication error between the main controller and the fan, meaning the unit is unable to start up properly.. It appears on 1 Johnson Starley model in our database.

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: 38
Typical repair cost £150-300 (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 1.91 fault code

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

Source

Johnson Starley 1.91 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 7 July 2026