Your boiler's internal computer has encountered a memory or software error and can no longer control the heating properly.

Internal fault

What causes this fault?

This fault occurs when the boiler's control center suffers a critical failure in its internal memory or software processing. It is essentially a terminal logic error where the circuit board can no longer safely calculate how much gas or heat to provide. The most common reason is age-related degradation of the electronic components, which causes them to lose their pre-programmed settings.