High Lockout
F12 on Vaillant ecoMAX Pro 28E

Your boiler's main control panel is having trouble communicating with the internal display or remote controls.

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.

Technical description

No reception by the local user interface

What causes this fault?

This fault occurs when the main brain of the boiler loses its digital connection with the display panel or external controls. The most common reason is a loose or damaged internal wiring connection, though it can also be caused by an electrical component on one of the circuit boards wearing out.

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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