High
75 on Vokera Syntesi 25

Your boiler has detected an internal electrical communication error or a wiring issue that is preventing it from working safely.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Wiring fault

From this model's manual
Verified against the Vokera Linea He installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This fault occurs when the boiler's internal computer loses the ability to communicate with its electrical components. It is physically caused by loose connections in the wiring harness or a failure in the circuit board that prevents signals from being sent correctly. In some cases, electrical interference or dampness on the wires can lead to these two specific codes.

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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