E05 High

Alpha E05 Fault Code

The Alpha E05 fault code means: your boiler has lost the ability to accurately measure the temperature of the water circulating through your radiators, so it has shut down to prevent potential overheating.. It appears on 30 Alpha 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: Heating flow sensor fault
Typical repair cost £120-220 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Alpha models that show the E05 fault code

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

Source

Alpha E05 fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026