Your boiler's main control unit has detected an electrical problem with its temperature sensors, meaning it has shut down as a precaution to prevent damage.

Electronics temperature too high. Electronics too hot due to external effect, electronics defective

What causes this fault?

This fault occurs when the boiler's internal electronic control board reaches an unsafe operating temperature, triggering an automatic shutdown to prevent the components from melting or catching fire. The most common reason is a hardware failure within the circuitry of the main board or the display interface, though extreme external heat or poor ventilation around the boiler casing can also contribute.