High
15 on Alpha Evoke 10 / 18

Your boiler’s internal computer is confused because its software settings do not match the physical parts installed, causing the system to stop working for safety.

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

Incorrect hydraulic configuration. There is an inconsistency between the settings and signals received from the PCB

From this model's manual
Verified against the Alpha Evoke installation & service manual, page 47.
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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