BoilerFaultCodesYour boiler is having trouble lighting the flame when you turn on your hot water taps.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: DHW ignition error
What causes this fault?
This fault occurs when the boiler fails to establish or sustain a flame specifically while trying to heat your tap water. It is usually caused by a component failure that prevents the spark from jumping or the gas from flowing correctly, meaning the system cannot safely ignite to provide heat. The most common reasons include a worn-out ignition probe or a faulty gas valve that isn't opening as it should.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like S.23 — 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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