BoilerFaultCodesYour boiler’s main control board has detected an internal computer failure, which means the system cannot manage itself safely and has stopped working.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Controller DBM23B error – controller could have an internal error
What causes this fault?
This fault occurs when the boiler's internal computer brain suffers a software or hardware crash, preventing it from safely monitoring the gas valve and sensors. The most common reason is a component failure on the main circuit board caused by age or occasional electrical surges that damage the delicate microchips.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like F50 — 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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