Your boiler's internal computer has encountered a critical electronic glitch that is preventing it from running safely.

Internal error / Sensor test failed / Recycle time error / Too many short burner starts without confirmation

What causes this fault?

This fault occurs when the boiler's central control board suffers a critical electronic failure, meaning it can no longer communicate with the internal components. The most common reason is a hardware malfunction within the circuitry or an electrical surge that has damaged the delicate microprocessors. In some cases, loose or damaged wiring connections between the board and the sensors can also trigger this shutdown.