BoilerFaultCodesWhat the manual says
Manufacturer manualIgnition sequence (heating operation)
From this model's manual
Verified against the Vaillant/Vaillant Ecotec Exclusive 74c27d installation & service manual, page 43.
What causes this fault?
This is a normal part of the boiler's operation and occurs every time the system detects a demand for warmth in your radiators. It indicates that the internal fans are spinning and the gas valve is opening to create the spark needed for a flame. You will only see this code during the few seconds it takes for the boiler to successfully ignite.
DIY fix possible
This fault may be fixable without an engineer. Check your manual first.
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Related fault codes
All 71 fault codes on the ecoTEC exclusive 838
Seeing a different code? Every code this model can display, in one place.