Your boiler has detected a communication problem between its internal sensors or a fault in its main control board, causing the system to shut down for safety.

Electronics / NTC error

What causes this fault?

This fault occurs when the boiler's internal computer receives conflicting information from its temperature sensors or detects a short circuit in the wiring. The most common reason is that either the flow or return sensors have failed, or the main circuit board can no longer accurately process the signals it is receiving.