Biasi Garda M90f. 24SR Fault codes & diagnostics

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

Combi Natural Gas 2002-2007 Discontinued
GC Number 41-970-10
Download the Biasi Garda M90f. 24SR manualThe official installation and service manual (PDF), the document these fault codes were read from. 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 1 documented codes

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lock-out light

Your boiler has shut down for safety because it either failed to light, sensed it was getting too hot, or detected an issue with how it clears waste gases.

High DIY-safe £100-350

What to check first

  1. Check that your gas pre-payment meter (if applicable) has credit.
  2. Ensure any external gas isolation valves are fully open.
  3. Press and release the reset button on the front control panel to see if the boiler restarts.

Parts commonly replaced

  • Ignition Electrode
  • Safety Thermostat
  • Air Pressure Switch
  • Gas Valve
Full explanation for lock-out light
Status & diagnostic codes

4 operating states & engineer diagnostics

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

1 second ON 1 second OFF Status Your boiler has detected that the temperature is low and is running its internal protection mode to prevent the pipes from freezing. 10 Diagnostic Your boiler has detected an issue with the air intake or exhaust system, which prevents it from operating safely. 12 Diagnostic Your boiler has detected an issue with the electrical circuit board or its internal wiring, preventing it from operating correctly. A short pulse every 4 seconds Status Your boiler is currently switched off but is monitoring the temperature to prevent the internal pipes from freezing.