BoilerFaultCodesYour boiler is struggling to light properly 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 mode ignition error
What causes this fault?
This fault occurs when the boiler detects that the burner is failing to light or stay lit specifically while trying to heat your domestic hot water. The most common reasons are a weak spark from worn-out ignition parts or a gas valve that isn't opening correctly to provide fuel. It can also be caused by moisture on the electrodes or a communication error within the core control board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like S13 — 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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