A8 Low

Sime A8 Fault Code

The Sime A8 fault code means: your boiler has recorded a fault in its memory history, but this code specifically identifies that there is no active error currently preventing the unit from operating.. It appears on 1 Sime model in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Code of last error -8

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 A8 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Sime A8 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