ALL 80 High

Sime ALL 80 Fault Code

Also written as ALL80 — same fault.

The Sime ALL 80 fault code means: your boiler has detected an electrical communication problem with one of its internal control components, which is preventing the system from operating correctly.. It appears on 3 Sime models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Fault on the valve control logic line/valve cable damaged
Typical repair cost £150-250 (including labour)

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 ALL 80 fault code

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

Source

Sime ALL 80 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