High
F.49 on Vaillant ecoFIT Pure 412

Your boiler is having trouble communicating with its external controls, such as your thermostat or programmer, due to an electrical signal error.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

eBUS voltage fault

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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Related fault codes

F.73View →F.74View →

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