Your boiler has detected a general internal fault and has stopped working to prevent damage or safety issues.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fault condition
What causes this fault?
This fault occurs when the boiler's internal computer detects an interruption in the sequence required to maintain a safe flame. The most common reasons are a failure to produce a spark at the burner or the control board losing communication with essential mechanical parts like the fan. Essentially, the system has detected that it can no longer guarantee safe operation and has shut down as a protective measure.
DIY fix possible
Locate the reset button on the front control panel.Press and hold the reset button for approximately five seconds.Wait to see if the blue light stays solid and the boiler restarts.
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 Indicator light flashes slow (constant interval) — no call-out fees, no surprises.
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Worcester Bosch Greenstar 24i Junior 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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