BoilerFaultCodesSime AL 41 Fault Code
Also written as AL41 — same fault.
The Sime AL 41 fault code means: your boiler has failed to stay lit after six attempts and has shut down to prevent damage, possibly due to a fuel supply issue or a faulty internal sensor.. It appears on 14 Sime models in our database.
Technical description: Flame loss more than 6 consecutive times — check ignition/detection electrode; verify gas supply and pressure
DIY fix possible
Check if other gas appliances (like a hob) are working to confirm your gas supply is active.If you have a prepay meter, check that you have sufficient credit.Press and hold the 'Reset' button for 1 to 5 seconds to attempt a restart.
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Sime models that show the AL 41 fault code
Click a model for the full fault code list and model-specific repair notes.
- Brava One HE Repair: £100-£250
- Brava Slim HE Regular Repair: £120-280
- Brava Slim HE System Repair: £120-£280
- Dewy 30/130 HE FS Repair: £120-280
- Dewy 30/50 HE WM Repair: £120-280
- Giulia Combi 30 Repair: £120-350
- Halstead Trio Repair: £100-£250
- Mia 30 Repair: £120-350
- Murelle One HE Repair: £120-280
- Murelle Pro HE 25 HO Repair: £100-£250
- Murelle Pro HE Combi Repair: £120-280
- Murelle Pro HE MkII Combi Repair: £120-350
- Murelle Pro HE R MkII System Repair: £120-280
- Murelle Pro HE System R Repair: £120-280
Source
Sime AL 41 fault code information on this page is sourced and cross-checked against the official Sime service / installation manuals for each affected model.
- Sime Brava One HE manual (PDF)
- Sime Brava Slim HE System manual (PDF)
- Sime Dewy 30/130 HE FS manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026