BoilerFaultCodesWhat the manual says
Manufacturer manualIncorrect signal from fan
What causes this fault?
This fault occurs when the boiler's main computer loses the ability to accurately control or monitor the speed of the fan. It is usually caused by an internal electronic failure within the fan motor itself or a loose connection in the wiring that carries signals between the fan and the control board. Without a reliable signal, the boiler shuts down as a safety precaution to ensure waste gases are being properly extracted.
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.
Avoid the next call-out bill
A cover plan would handle faults like b29: no call-out fees, no surprise bills.
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