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:
- A blind filter
- a scourer
- an absorbent cloth
- group head seal brush
- detergent specifically for backflushing a coffee machine
- a 500ml container e.g. ice cream or fruit container or large milk jug
Water Backflush (every few days):
- Remove filter basket and clean basket and group handle
- 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)
- Scrub the shower screen and group seal with the group head brush
- Loosely flush again with the blind filter, then put the handle tightly onto the group head
- 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)
- Put your filter basket back into the group handle Chemical Backflush (every 1-4 weeks):
- Do a water backflush, then:
- Add ¼ teaspoon of backflushing detergent into the blind filter and place tightly onto group head
- 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
- Activate brew lever/button/switch for 5 seconds, turn off and leave for 30 seconds – repeat 3 times
- Remove the group handle and rinse detergent out – loosely flush group head to remove solution from the shower screen and seal
- 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:
- Take the filter basket and using a steel wool soapy pad clean basket and group handle well
- In a bucket of HOT water add 1 teaspoon of backflushing detergent.
- Place group handle and filter basket into solution. ENSURE THE RUBBER HANDLE IS NOT TOUCHING THE WATER. Soak for 30 minutes then rinse well.
- Rinse the group handle and filter basket well & put back together
- Place the group handle onto the group head and activate the brew button/lever/switch for a couple of seconds to flush water through
