Your boiler's electronic control board has been set up with incorrect configuration settings or a missing physical connection, preventing it from operating.

Jumper tag fault

What causes this fault?

This fault occurs when the boiler's main control board is missing a small physical plug, known as a jumper, which tells the computer exactly which model it is installed in. It usually happens after a new circuit board has been fitted but not configured correctly, or if a component has vibrated loose over time. Without this specific hardware setting, the boiler shuts down for safety because it doesn't know its own operating limits.