BoilerFaultCodesWhat the manual says
Manufacturer manualflow/return ∆T error (2nd CH)
From this model's manual
Verified against the Vokera Linea He installation & service manual, page 33.
What causes this fault?
This fault occurs when the boiler's internal computer experiences a software glitch or loses communication with the sensors and valves it controls. The most common reason is a momentary power fluctuation or a breakdown in the wiring connections that prevents the main control board from processing data correctly.
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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