BoilerFaultCodesWhat the manual says
Manufacturer manualBurner
From this model's manual
Verified against the Vaillant Ecotec Plus 826 installation & service manual.
What causes this fault?
This message appears because the internal control board is performing a brief safety verification of the gas burner's functionality during the ignition sequence. It is a completely normal part of the boiler's startup procedure used to ensure the system is operating correctly before it begins heating. This is not a physical failure or a breakdown, but rather a standard status update from the boiler's software.
DIY fix possible
Wait for 2-5 minutes to see if the status code clears automaticallyCheck that your gas supply is active at the meterEnsure your thermostat is calling for heat
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