How much does it cost to fix Keston error code 2 nn?

Typical repair cost for the Keston 2 nn fault is £180-350 including labour.

2 nn High

Keston 2 nn Fault Code

Q: What does the Keston 2 nn fault code mean?

Your boiler is currently unable to light the burner because it cannot generate the electrical spark required to start the flame.

Also written as 2NN — same fault.

The Keston 2 nn fault code means: your boiler is currently unable to light the burner because it cannot generate the electrical spark required to start the flame.. It appears on 1 Keston model in our database.

Technical description: Module generating spark ignition

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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Keston models that show the 2 nn fault code

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

C90 / C110 Repair: £180-350

Source

Keston 2 nn 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 27 April 2026