29 High

Gledhill 29 Fault Code

The Gledhill 29 fault code means: your boiler has detected an internal communication error with its main control board, meaning it cannot process instructions correctly and has stopped working for your safety.. It appears on 1 Gledhill 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: AD_LO_CPL_ERROR
Typical repair cost £250-450 (including labour)

Engineer required

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

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Gledhill models that show the 29 fault code

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

Source

Gledhill 29 fault code information on this page is sourced and cross-checked against the official Gledhill service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026