BoilerFaultCodesYour boiler's computer is confused because it thinks a new component has been plugged in or a setting has changed, and it needs to be told how to work with the updated 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: BUS device changed or replaced. Check system configuration for heating circuit!
What causes this fault?
This fault occurs when the boiler's main control board loses its connection with a key component or detects that a new part has been installed without being properly synced. The most common reason is a communication error between the boiler and a smart thermostat, or a hardware glitch that happens after a power surge or a recent repair where settings weren't fully saved.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like Fault 13 / 158 — 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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