Glow-worm Orange 'Mains' light Fault Code
Also written as ORANGEMAINSLIGHT — same fault.
The Glow-worm Orange 'Mains' light fault code means: your boiler is receiving electrical power, but if the light is off, there may be a problem with the electricity supply or the internal circuit board.. It appears on 1 Glow-worm model in our database.
Technical description: Indicates if the mains power is illuminated/available inside the appliance.
What causes the Glow-worm Orange 'Mains' light fault?
This issue occurs when the electrical current fails to reach the boiler's control system, either due to a tripped switch in your home's fuse box or a blown fuse inside the appliance itself. It is often caused by a sudden power surge or a failing internal component that has caused the circuit to break for safety.
This fault is more frequent during storm season, as lightning strikes or local power grid fluctuations are more likely to blow the boiler's internal fuses.
DIY fix possible
Check that the boiler's power switch is turned onCheck your home’s main fuse box for a tripped circuit breakerEnsure the fused spur switch near the boiler is turned on
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Gas Safe Register →Glow-worm models that show the Orange 'Mains' light fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm Orange 'Mains' light 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