Ideal C80ff / C95ff Fault codes & diagnostics

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

Regular Natural Gas 23-28 kW 1997-2005 Discontinued

Replaced by: Classic

Download the Ideal C80ff / C95ff manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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Fault codes

All 2 documented codes

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E00-684

Your boiler is failing to detect that the water pump or flow valve has activated, which prevents the unit from heating your home or water.

High Engineer only £150-250 Shared across the range

Parts commonly replaced

  • Microswitch assembly
  • Diverter valve diaphragm
Full explanation for E00-684
E00-688

Your boiler has detected an issue with the internal water pressure sensor, which is preventing it from safely lighting the burner.

High Engineer only £150-250 Shared across the range

Parts commonly replaced

  • Pressure switch
  • Microswitch
Full explanation for E00-688