How to backflush your espresso machine

Espresso machines with 3 way solenoid valves can be “back flushed”. This process cleans the group head of rancid coffee oils and should be carried out every 2 to 4 weeks on a machine which is used daily at home.

You will need:

  1. A blind filter
  2. a scourer
  3. an absorbent cloth
  4. group head seal brush
  5. detergent specifically for backflushing a coffee machine
  6. a 500ml container e.g. ice cream or fruit container or large milk jug

Water Backflush (every few days):

  1. Remove filter basket and clean basket and group handle
  2. Insert a blind filter into the group handle. Place handle into group head lightly and activate the brew button for a few seconds, swivelling the group handle so the water flushes over the sides to rinse out the seal and shower screen (you don’t want to create a seal)
  3. Scrub the shower screen and group seal with the group head brush
  4. Loosely flush again with the blind filter, then put the handle tightly onto the group head
  5. Activate the brew lever/button/switch for 5 seconds (or if you have a brew pressure gauge until the pressure builds up to 9 bar) then turn off – repeat 5 times. (Ensure you don’t leave the brew button/lever on for too long – you will overwork the pump)
  6. Put your filter basket back into the group handle Chemical Backflush (every 1-4 weeks):
  7. Do a water backflush, then:
  8. Add ¼ teaspoon of backflushing detergent into the blind filter and place tightly onto group head
  9. Activate the brew button/lever/switch for 5 seconds then turn it off. Repeat until you see soapy water come out the bottom into the drip tray
  10. Activate brew lever/button/switch for 5 seconds, turn off and leave for 30 seconds – repeat 3 times
  11. Remove the group handle and rinse detergent out – loosely flush group head to remove solution from the shower screen and seal
  12. Insert handle fully, activate brew lever/button for 5 seconds, turn off for 3 seconds – repeat 8-10 times, until the water runs clear – if the solution is left in the machine it can solidify – it’s important to rinse well! Do steps 13-17 as necessary:
  13. Take the filter basket and using a steel wool soapy pad clean basket and group handle well
  14. In a bucket of HOT water add 1 teaspoon of backflushing detergent.
  15. Place group handle and filter basket into solution. ENSURE THE RUBBER HANDLE IS NOT TOUCHING THE WATER. Soak for 30 minutes then rinse well.
  16. Rinse the group handle and filter basket well & put back together
  17. Place the group handle onto the group head and activate the brew button/lever/switch for a couple of seconds to flush water through