BoilerFaultCodesSime 01 Fault Code
The Sime 01 fault code means: your boiler has failed to ignite or stay lit, meaning it cannot produce heat or hot water until the issue is addressed.. It appears on 3 Sime models in our database.
Technical description: Combustion configuration
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Sime models that show the 01 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Sime 01 fault code information on this page is sourced and cross-checked against the official Sime service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026