C13 High

Gledhill C13 Fault Code

The Gledhill C13 fault code means: your boiler has experienced an internal software or communication error and has stopped working to protect itself.. 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: STATE_ERROR
Typical repair cost £100-£350 (including labour)

DIY fix possible

Turn the boiler's electrical power switch offWait for approximately 30 secondsTurn the power back on to see if the system clears the internal error

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Gledhill models that show the C13 fault code

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

Source

Gledhill C13 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