K High

Baxi K Fault Code

The Baxi K fault code means: your boiler is temporarily locked out because it cannot accurately read its internal temperatures or suspects a blockage inside the heating system.. It appears on 5 Baxi models 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: Temperature sensors faulty or heat exchanger obstruction
Typical repair cost £150-350 (including labour)

Engineer required

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

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Baxi models that show the K fault code

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

Source

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

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026