Hi Viv,
F15 error means that there is an issue with the virtual sensor.
F02 error means that Water fill solenoid valve failure.
We recommend you call our customer service centre to book an engineer on 0208 226 3633.
Or you can book a repair here
https://www.northlondonappliancerepairs.co.uk/book-a-service.html.
If you have any more question let me know.