20.0 High

Grant 20.0 Fault Code

Also written as 200 — same fault.

The Grant 20.0 fault code means: your boiler has detected a failure in the ignition process, meaning it is currently unable to start up or stay lit to provide heat and hot water.. It appears on 1 Grant model 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: 20.0
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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Grant models that show the 20.0 fault code

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

Source

Grant 20.0 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