BoilerFaultCodesYour boiler is currently providing hot water but has likely detected a sensor fault or is stuck in hot water mode, which might prevent your central heating from coming on.
This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.
Technical description: DHW operation
What causes this fault?
This code appears when the boiler believes there is a continuous demand for hot water, even if you aren't running a tap. It is typically caused by a stuck internal flow switch or a faulty temperature sensor sending incorrect signals to the control board. If the boiler stays in this mode indefinitely, it will prioritize hot water and refuse to turn your radiators on.
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 6 — no call-out fees, no surprises.
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