Heatline Compact 20 Fault codes & diagnostics

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

System Natural Gas 20 kW Discontinued
GC Numbers 41-157-0341-157-0141-157-02
Download the Heatline Compact 20 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 →

Fault codes

All 2 documented codes

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flame or gas fault

Your boiler has failed to ignite or lost its flame, meaning it cannot produce heat or hot water.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • Printed Circuit Board
Full explanation for flame or gas fault
overheat fault

Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.

High Engineer only £120-220

Parts commonly replaced

  • Overheat thermostat
  • Pump
  • Diverter valve
  • Primary heat exchanger
Full explanation for overheat fault