BoilerFaultCodesWhat the manual says
Manufacturer manualDHW mode: Ignition
From this model's manual
Verified against the Vaillant Ecotec Exclusive installation & service manual, page 53.
What causes this fault?
This fault occurs when the boiler is unable to successfully establish a flame after several attempts. The most common reasons are a lack of gas supply to the unit, a worn-out ignition electrode that is failing to create a spark, or a faulty gas valve that isn't opening correctly.
This issue can occur in winter if the external gas regulator freezes or if the gas meter becomes restricted by extreme cold.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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