Warmworld HE 70/80 Fault codes & diagnostics

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

Regular Natural Gas 70 kW 1993 onwards Discontinued
Download the Warmworld HE 70/80 manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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Fault codes

All 1 documented codes

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LOCKOUT

Your boiler has shut down because its exhaust system has become too hot, which is a safety feature to prevent damage or dangerous fumes.

High Engineer only £120-250 Community-sourced, unverified

Parts commonly replaced

  • Flue thermostat
  • Main heat exchanger
  • Burner gasket

Related codes

Full explanation for LOCKOUT
Status & diagnostic codes

4 operating states & engineer diagnostics

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

30 Diagnostic Your boiler is struggling to breathe properly because the airflow inside the unit is blocked or restricted. 40 Diagnostic Your boiler has detected an issue with the air intake or exhaust flue system, preventing it from operating safely. 50 Diagnostic Your boiler has detected an issue with the air intake or exhaust flue system, preventing it from operating safely. 80 Diagnostic Your boiler is detecting an issue with the air intake or exhaust ventilation system that prevents it from burning fuel safely.