26.0 Medium

Grant 26.0 Fault Code

Also written as 260 — same fault.

The Grant 26.0 fault code means: your boiler is displaying a technical setting that indicates it is currently locked to its maximum heating capacity, which usually suggests a configuration or electronic control board error rather than a physical breakdown.. It appears on 8 Grant models in our database.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: Maximum heat output (Kerosene) (kW)
Typical repair cost £120-250 (including labour)

Engineer required

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

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Grant models that show the 26.0 fault code

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

Source

Grant 26.0 fault code information on this page is sourced and cross-checked against the official Grant service / installation manuals for each affected model.

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