Vokèra · Vision, Compact A and Unica A-code platform
A03Fan tachometer signal fault
This code applies to Vision 25C, Vision 30C, Compact A, Unica 28i, Unica 32i. Fault codes narrow down the likely problem, but they do not replace a model-specific diagnosis.
What you can safely check
- Do not open the case or inspect the fan or flue yourself.
- Arrange a Gas Safe registered engineer.
How an engineer may fix it
Check fan movement and speed feedback, wiring and connectors, air/flue restrictions and the control board; repair or replace the defective part and verify combustion.
Some status codes apply only to certain variants. Confirm the exact user manual.
Manufacturer source: Vokèra — Vision Combi 25C/30C User, Installation and Servicing Manual. Checked 15 August 2026. The appliance manual and an engineer’s on-site diagnosis take precedence. Never remove the boiler case yourself.