BoilerFaultCodesGlow-worm Pictogram of a spark Fault Code
Also written as PICTOGRAMOFASPARK — same fault.
The Glow-worm Pictogram of a spark fault code means: your boiler is failing to light because it isn't receiving a gas supply or cannot detect a flame.. It appears on 3 Glow-worm models in our database.
Technical description: No gas supply. To rectify: Switch off the boiler, rectify the gas supply problem, and restart the boiler.
What causes the Glow-worm Pictogram of a spark fault?
This fault occurs when the boiler's internal computer tries to start the burner but cannot establish a sustained flame. The most common reasons are a temporary interruption in your gas supply, a worn-out ignition probe that cannot create a spark, or a faulty gas valve failing to release fuel into the combustion chamber.
This fault can occur more frequently during extreme cold snaps if the external gas meter regulator freezes, restricting the flow of gas to the property.
DIY fix possible
Check that your gas emergency control valve (usually by the meter) is in the 'on' position.If you have a pre-payment meter, check that you have sufficient credit.Check if other gas appliances in the home, such as a hob, are working correctly.Press and hold the reset button for five seconds to see if the boiler restarts.
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Glow-worm models that show the Pictogram of a spark fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm Pictogram of a spark 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 7 July 2026