Enn High

Keston Enn Fault Code

Also written as ENN — same fault.

The Keston Enn fault code means: your boiler has encountered a critical system error that has forced it to shut down to prevent damage or unsafe operation.. It appears on 1 Keston 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: Fault causing a boiler shutdown
Typical repair cost £150-450 (including labour)

DIY fix possible

Turn the power switch to the boiler off and wait for 30 secondsTurn the power back on to see if the system recalibratesPress and hold the 'Reset' button for three seconds

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Keston models that show the Enn fault code

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

Source

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

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