BoilerFaultCodesTechnical description
System configuration: new BUS device. New ISM detected.
What causes this fault?
This fault occurs when the boiler's main internal computer detects a new electronic component or a communication shift within its wiring system. It is most commonly triggered after a power surge, a recent part replacement, or if the main circuit board loses its stored memory settings and needs to be re-told which model it is operating.
This fault may be slightly more common after summer storms, as power surges from lightning or grid instability can disrupt the boiler's electronic memory.
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 →