BoilerFaultCodesYour boiler is struggling to spark or light the gas correctly, which is a safety mechanism preventing it from trying to ignite for too long.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Maximum ignition time
What causes this fault?
This fault occurs when the boiler's internal safety system detects that the gas has failed to ignite within the safe time limit allowed. The most common reasons are that the spark electrode is too worn to create a flame, or the gas valve isn't opening correctly to let fuel into the burner. In some cases, it can also be caused by a blockage in the flue or a fault in the main control board failing to send the ignition signal.
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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Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like D.65 — 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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