BoilerFaultCodesSime 09 Fault Code
The Sime 09 fault code means: your boiler is struggling to push water around your heating system, which is often caused by trapped air, a blockage, or a pump that has stopped working.. It appears on 2 Sime models in our database.
Technical description: WATER CIRCULATION ERROR
DIY fix possible
Check your boiler pressure gauge and top it up to 1.5 bar if it is below 1 bar.Bleed all radiators in your home to ensure there is no trapped air preventing flow.Ensure all radiator valves are fully open to allow water to circulate freely.
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Sime models that show the 09 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Sime 09 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