High Lockout
FAIL POINT I on Worcester Bosch 24/28CDi II RSF

Your boiler has detected a problem with one of its internal temperature sensors and has stopped working as a safety precaution.

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.

Technical description

Flashing fast (Sensor Fault)

What causes this fault?

This fault occurs when the boiler's control board loses communication with the temperature sensors or receives a reading that is outside of its safe operating range. The most common reason is that the internal thermistors have physically degraded over time or a wire has shaken loose, preventing the boiler from knowing if the water is becoming dangerously hot.

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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Related fault codes

FAIL POINT EView →FAIL POINT FView →

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