High
73 on Alpha Intec2 25 28XE

Your boiler has detected an inconsistent temperature reading between two of its internal safety sensors, causing it to shut down to prevent overheating.

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

High flow NTC and safety NTC difference detected. The board detects an anomaly in the temperature readings difference between the flow NTC and safety NTC sensors

From this model's manual
Verified against the Alpha Intec2 25 28xe installation & service manual.
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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