High
F20 on Saunier Duval Semia Condens F30 E

Your boiler's computer components are not communicating correctly, meaning the system cannot run because it does not recognize its own internal hardware configuration.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

Software incompatibility. Incorrect user interface or main board. Incorrect product code

From this model's manual
Verified against the Saunier Duval Semia Condens F30 E installation & service manual, page 35.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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