BoilerFaultCodesYour boiler has detected a new internal electronic component or communication device and requires a manual reset to confirm and sync the system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: System configuration: new BUS device. New ISM detected.
What causes this fault?
This fault occurs when the boiler's main control board detects a new electronic component or external wireless device trying to communicate with it. It acts as a security handshake, triggered because the system needs manual permission to integrate the new hardware and ensure it is compatible. The most common reason is that a new smart thermostat or internal wireless module has just been installed or replaced.
DIY fix possible
Locate the Reset button on the boiler control panelPress and hold the Reset button for approximately five secondsWait for the boiler to restart and check if the error code has cleared
Find a Gas Safe engineer
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A boiler cover plan would cover faults like Fault 11 / 131 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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