Your boiler's computer memory has encountered a software error and can no longer communicate correctly with the main control board.

Incorrect EEPROM signature

What causes this fault?

This fault occurs when the boiler's internal memory chip loses its identity or fails to share the correct security handshake with the main control board. The most common reason is a physical failure of the memory component on the circuit board, often caused by an electrical surge or simple component degradation over time. Because the boiler no longer knows its own operating parameters, it shuts down as a safety precaution.