Your boiler's computer brain has suffered a serious internal glitch and is unable to communicate with its own sensors or controls.

Internal error.

What causes this fault?

This fault occurs when the boiler’s main control board experiences a total communication failure between its internal components. It is often caused by an electrical surge, a moisture-related short circuit, or simply the natural degradation of the aging electronics inside the unit. Because the 'brain' can no longer process safety data, the boiler shuts down entirely to prevent any unsafe operation.