BoilerFaultCodesYour boiler is unable to start the small flame needed to ignite the main burner, meaning your heating and hot water will not work.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: PILOT WILL NOT LIGHT
What causes this fault?
This fault occurs when the boiler's small pilot flame fails to stay lit, which is necessary to safely ignite the main heating burners. The most common reasons are a buildup of soot blocking the tiny gas nozzle or a worn-out sensor that can no longer detect the heat from the flame.
This issue often surfaces in autumn when the boiler is switched back on after being idle all summer, as dust or debris can settle in the pilot assembly during the warmer months.
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 49 — no call-out fees, no surprises.
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