How much does it cost to fix Keston error code E46?

Typical repair cost for the Keston E46 fault is £120-350 including labour.

E46 High

Keston E46 Fault Code

Q: What does the Keston E46 fault code mean?

Your boiler's main control panel has lost connection with the internal computer that runs it, meaning the boiler cannot receive commands.

The Keston E46 fault code means: your boiler's main control panel has lost connection with the internal computer that runs it, meaning the boiler cannot receive commands.. It appears on 9 Keston models in our database.

Technical description: Flue sensor open circuit - check connections to flue sensor are in place

What causes the Keston E46 fault?

This fault occurs when the data link between the boiler's display screen and the main internal computer is broken or interrupted. The most common reason is a loose or damaged wiring connection inside the casing, though it can also be caused by moisture affecting the delicate electronic circuit boards.

Typical repair cost £120-350 (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 E46 fault code

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

Source

Keston E46 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