BoilerFaultCodesGlow-worm Red light flashes Fault Code
Also written as REDLIGHTFLASHES — same fault.
The Glow-worm Red light flashes fault code means: your boiler has entered a safety lockout mode and has stopped running to protect its internal components.. It appears on 1 Glow-worm model in our database.
Technical description: Indicates a lockout condition; momentarily interrupt the electrical supply to reset.
What causes the Glow-worm Red light flashes fault?
This fault occurs when the boiler fails to detect a flame after several attempts, causing it to shut down for safety. The most common reasons include a worn-out ignition spark that can no longer light the gas, or a faulty gas valve that isn't letting fuel into the burner. In some cases, the internal control board may be failing to send the correct electrical signals to start the sequence.
DIY fix possible
Locate the boiler's electrical power switch (fused spur) on the wall nearby.Switch the power off for approximately 10 seconds.Switch the power back on and wait to see if the red light clears and the boiler fires up.
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Gas Safe Register →Glow-worm models that show the Red light flashes fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm Red light flashes fault code information on this page is sourced and cross-checked against the official Glow-worm service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026