Place some coffee machine detergent in a blind portafilter
Press Button 1 and Button 2 together. This will do a quick backflush and stop.
Wait for a minute to let the detergent activate.
Press B1 & B2 together again.
Wait for about 30 seconds
Repeat step 4.
Finally, run the automatic backflush by pressing B1 & B3 together.
This runs several (8, I think) backflushes before coming to a halt.
Side note: I have to press B1 & B2 in a rapid succession to get this
activated, pressing it together at the same time doesn’t work.
Repeat step 7 depending on how far back the last backflush was