BoilerFaultCodesWhat the manual says
Manufacturer manualMaintenance:Demomode
From this model's manual
Verified against the Vaillant Ecotec Plus Regular installation & service manual, page 33.
What causes this fault?
This fault occurs when the boiler's software is accidentally placed into 'Showroom Mode', which is a setting intended for shop displays only. It means the control board thinks it should only light up the screen for demonstration rather than actually igniting the gas to heat your home. This is usually caused by a technician forgetting to deactivate the setting during installation or a mistake within the service menu.
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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