BoilerFaultCodesYour boiler's small starter flame is either too weak or not staying lit, which is preventing the main burner from firing up to provide heat.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Pilot rate too low.
What causes this fault?
This fault occurs when the small pilot flame remains too small or weak to heat the safety sensor properly. The most common reasons are a tiny piece of debris blocking the pilot jet or a failing thermocouple that can no longer detect the heat of the flame, causing the boiler to shut down for safety.
This issue often appears after the boiler has been turned off for the summer, as dust and debris can settle in the pilot assembly during periods of inactivity.
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 B(3) — no call-out fees, no surprises.
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Potterton Flamingo RS40 RS50 is discontinued — time for a new one?
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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