How do I backflush my espresso machine?

Backflushing forces cleaning solution backward through the group head to remove coffee oils. Steps: insert a blind basket (no holes) in the portafilter, add backflush detergent (Cafiza), lock in, run the pump for 5 seconds, stop for 10 seconds, repeat 5–10 cycles, then run clean water cycles to rinse. Backflush with detergent weekly and with plain water daily. Only machines with a 3-way solenoid valve (most prosumer machines) can be backflushed.