BoilerFaultCodesYour boiler is struggling to light the flame correctly, meaning your heating and hot water may not work reliably.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: ignition
What causes this fault?
This fault occurs when the boiler attempts to start up but fails to establish or maintain a stable flame during the ignition sequence. The most common reasons are worn-out sparks that cannot light the gas or a faulty sensor that fails to detect the flame once it is lit.
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.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like S.03 — no call-out fees, no surprises.
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Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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