Glow-worm EnergySaver Fault codes & diagnostics

1 fault code with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

Regular Natural Gas 1993-2003 Discontinued
GC Numbers 41-319-7141-319-8541-319-9241-319-9441-319-9541-319-7241-319-7341-319-7441-319-7641-319-77
Download the Glow-worm EnergySaver manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Versions & GC numbers

Which version do you have?

The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.

GC number Appliance (register name) Produced
41-319-71 Energysaver 60 1993–2003
41-319-85 Energysaver 80P 1994–2003
41-319-92 Energysaver 70 1994–2002
41-319-94 Energysaver 50e 1996–2002
41-319-95 Energysaver 60e 1996–2002
41-319-72 Energysaver 40P 1993–2003
41-319-73 Energysaver 50P 1993–2002
41-319-74 Energysaver 60P 1993–2003
41-319-76 Energysaver 30e 1994–2002
41-319-77 Energysaver 40e 1994–2002
Fault codes

All 1 documented codes

Tap any card for details

APS neon lit

Your boiler has detected an issue with the airflow system, which is preventing the burner from lighting for safety reasons.

High Engineer only £120-250

Parts commonly replaced

  • Air Pressure Switch
  • Fan Assembly
  • Venturi Tube
Full explanation for APS neon lit
Status & diagnostic codes

14 operating states & engineer diagnostics

Not faults — these are normal operating states. Tap to expand.

4.5 Diagnostic Your boiler is struggling to maintain the correct internal pressure required to safely burn the gas needed to heat your home. 8.79 Diagnostic This code is not actually an error, but a technical display showing the boiler's current power output level while it is operating normally. 10.16 Diagnostic Your boiler is displaying a technical system parameter rather than a breakdown error, usually indicating a configuration or communication issue between internal components. 11.8 Diagnostic Your boiler is detecting an issue with the gas pressure being supplied to the burner, which prevents it from heating your water or home safely. 14.3 Diagnostic Your boiler has detected an issue with the internal gas pressure regulation, meaning it cannot safely control the size of the flame required to heat your home. 14.65 Diagnostic Your boiler is currently performing a diagnostic check to confirm its heating output levels and is not experiencing a functional fault. 16.12 Diagnostic Your boiler is currently performing a routine self-check of its heating power output and is not reporting an active fault. 16.94 Diagnostic Your boiler is displaying a technical information code rather than a fault, indicating the system is reporting its power settings to the display. 17.0 Diagnostic Your boiler has detected an incorrect internal gas pressure, which means it cannot safely ignite or heat your water. 17.58 Diagnostic Your boiler is displaying a status message indicating the current heating power level it is operating at, rather than reporting a system fault. 18.64 Diagnostic Your boiler is displaying a technical configuration code that indicates it is not currently set up to operate correctly for your home. 20.33 Diagnostic Your boiler is displaying a technical system information code rather than a fault, which usually occurs when the unit has been recently installed or had its settings adjusted. High neon light Status Your boiler's status light indicates it is running at its maximum heating power, but if the light remains off while the boiler is struggling, there may be an internal electrical communication fault. Low neon light Status Your boiler is struggling to maintain a strong flame, which is why it keeps turning off or failing to heat up properly.