Your boiler has detected an internal communication error between its electrical sensors and the main control board, causing it to shut down for safety.

Electronics/NTC fault. Short-circuit in flow or return NTC or electronics defective

What causes this fault?

This fault occurs when the boiler's main computer receives conflicting or impossible signals from the internal temperature sensors. The most common reason is an electrical short-circuit or a component failure on the main circuit board, which prevents the boiler from safely monitoring the water temperature.