High Lockout
FC on Worcester Bosch Greenstar 25HE

Your boiler's main control panel has lost communication with the internal computer, meaning the display cannot show information or process commands.

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

Textdisplay not detected.

What causes this fault?

This fault occurs when the digital screen on the front of your boiler can no longer talk to the main internal computer board. The most common reason is a loose or damaged connection in the internal wiring, or a hardware failure within the display panel itself. Without this communication link, the boiler cannot receive instructions and shuts down as a safety precaution.

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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