Worcester Bosch b1 Fault Code

What causes the Worcester Bosch b1 fault?

This fault occurs when the small memory chip, known as a code plug, becomes loose or fails, meaning the boiler's main computer can no longer identify which model it is controlling. Without this vital identity information, the boiler shuts down immediately as a safety precaution because it doesn't know its own operating limits. The most common cause is either a vibration-related loose connection or an internal electronic failure within the plug or the main circuit board.