How much does it cost to fix Keston error code 10 bar?

Typical repair cost for the Keston 10 bar fault is £150-300 including labour.

10 bar High

Keston 10 bar Fault Code

Q: What does the Keston 10 bar fault code mean?

Your boiler has detected that the water pressure within the hot water system is too high and has stopped operating to prevent damage.

Also written as 10BAR — same fault.

The Keston 10 bar fault code means: your boiler has detected that the water pressure within the hot water system is too high and has stopped operating to prevent damage.. It appears on 1 Keston model in our database.

Technical description: DHW max pressure

Typical repair cost £150-300 (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 10 bar fault code

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

R-sm 20 FB Repair: £150-300

Source

Keston 10 bar fault code information on this page is sourced and cross-checked against the official Keston service / installation manuals for each affected model.

Keston R-sm 20 FB manual (PDF)

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