Glow-worm Space Saver Compleheat 30 40 50 Fault codes & diagnostics

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

Regular Natural Gas 8.8-14.7 kW 1988-1994 Discontinued
GC Numbers 41-319-4241-319-4341-319-44
Download the Glow-worm Space Saver Compleheat 30 40 50 manualThe official installation and service manual (PDF), the document these fault codes were read from. PDF

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All 5 documented codes

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Neon 1

Your boiler is failing to start because it is not detecting electricity or there is not enough water pressure inside the system to operate safely.

High Engineer only £120-250

Parts commonly replaced

  • PCB fuse
  • Pressure switch
  • Control PCB
Neon 2

Your boiler has automatically shut down because it has detected that it is getting too hot inside, likely because the water is not circulating as it should.

High Engineer only £150-350

Parts commonly replaced

  • Central heating pump
  • Overheat thermostat
  • Printed Circuit Board

Related codes

Neon 3

Your boiler is failing to clear combustion gases properly, so it has safely shut down to prevent any risk.

High Engineer only £150-300

Parts commonly replaced

  • Air pressure switch
  • Fan assembly
  • Venturi/tubing

Related codes

Neon 4

Your boiler is failing to light the flame needed to heat your water or home, causing the system to shut down for safety.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed Circuit Board (PCB)
  • Flame rectification probe

Related codes

Red Neon on fascia

Your boiler has stopped working because the water pressure inside the heating system has dropped too low.

High DIY-safe

What to check first

  1. Locate the filling loop (usually a silver braided hose with one or two valves near the boiler piping).
  2. Slowly open the valve(s) to allow water to enter the system while watching the pressure gauge.
  3. Stop when the needle reaches the green zone (typically between 1.0 and 1.5 bar) and ensure both valves are tightly closed.

Parts commonly replaced

  • Filling loop
  • Pressure gauge
  • Pressure relief valve

1 operating states & engineer diagnostics

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