BoilerFaultCodesTechnical description
Main PCB memory fault
What causes this fault?
This fault occurs when the boiler's main control board suffers a hardware failure, specifically within its internal memory chip. It is usually caused by electrical wear and tear over time or a sudden power surge that corrupts the data the boiler needs to operate safely. Effectively, the board can no longer read its own internal instructions and must be replaced.
This fault is slightly more common during the winter months when boilers are under higher operational stress and stormy weather increases the risk of electrical surges.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register →