Hi I have a 2018 Audi a1 sline both wing mirrors have stopped heating . Heated rear window works and I can adjust both wing mirrors. Can’t find anywhere if there is a fuse for these and if so where ? TIA

Welcome Lorraine,

Maybe a daft comment, but the heating facility normally only works below 5 degrees C.

You don’t mention if this failure to operate has occurred since the rise in temperature. 
Beware, if you find the fuse has blown, it will have done so to protect the circuit, so you have to find the cause before just renewing the fuse.

Regards,

Gareth. 

Hi thanks for your speedy reply . It stopped working about two months ago so has been below and above temperature. I know this might sound daft but how would I know if there is an underlying cause? 

There has to be an underlying cause, if they aren’t working below 5 degrees.
Where that cause lies? - numerous possibilities from fractured wires in the flexible harness section twixt A post and door frame, failed switch, fractured wire within folding mechanism - the list goes on.

If it were mine, and I wasn’t equipped with a suitable meter and knowledge to use it, I would be buying an hour’s time with a trusted local autoelectrician. 
By the way, the fuse location should be listed in your handbook. 
Please let us know how you get on.

Regards,

Gareth.