Your boiler’s internal control board has developed a critical electronic fault and can no longer manage the heating process safely.

PCB Failure

What causes this fault?

This fault occurs when the boiler's internal electronic brain suffers a hardware failure, preventing it from processing information from the sensors. The most common reason is the natural degradation of electrical components on the circuit board over time, or a sudden voltage spike that has damaged the delicate circuitry. Because the board can no longer guarantee the boiler is operating safely, it shuts the system down entirely.