BoilerFaultCodesSime AL 57 Fault Code
Also written as AL57 — same fault.
The Sime AL 57 fault code means: your boiler has temporarily locked itself because it has detected an unusual temperature reading and needs to recalibrate its internal sensors to work correctly again.. It appears on 7 Sime models in our database.
Technical description: Lock for flow temperature (FT) check — carry out self-calibrating procedure
DIY fix possible
Locate the selector dial on the front of the boiler control panel.Turn the dial to the 'OFF/RESET' position and wait for 30 seconds.Turn the dial back to the desired setting to trigger the automatic self-calibration process.
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Sime models that show the AL 57 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Sime AL 57 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 Dewy 30/130 HE FS manual (PDF)
- Sime Dewy 30/50 HE WM manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026