BoilerFaultCodesSime 05 Fault Code
The Sime 05 fault code means: the boiler control buttons have become unresponsive, likely due to a software lock or a faulty display interface preventing you from changing settings.. It appears on 3 Sime models in our database.
Technical description: Timer block of the keys
DIY fix possible
Switch off the power to the boiler at the fused spur or mains switchWait for at least 60 seconds to allow the internal memory to clearTurn the power back on and check if the buttons respond correctly
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Sime models that show the 05 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Sime 05 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