BoilerFaultCodesWhat the manual says
Manufacturer manualSafetyswitch-off:Fluetemp.toohigh | Breakinplugconnectionforoptionalfluegassafetycut-out(SCO), breakincableharness
From this model's manual
Verified against the Vaillant Ecotec Exclusive installation & service manual, page 55.
What causes this fault?
This fault occurs when the boiler's internal computer loses communication with its safety sensors due to a break in the electrical circuit. It is typically caused by a loose connection, a damaged plug on the wiring loom, or a failure within the main control board itself.
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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