Breville BES870 how to replace the group-head seal
When espresso or water leaks around the portafilter because the silicone seal no longer seals.
You need
- Allen key (supplied)
- Skewer
- New silicone seal from Breville
- Long-nose pliers (optional)
Steps
WARNING
Do not immerse the power cord, plug or machine in water or any other liquid.
Marked WARNING by the manufacturer Source: Care & Cleaning: Using the Allen key, p. 27
- Switch the machine off with POWER and unplug it.
- Remove the water tank and drip tray; take care if they are full.
- Clean coffee out of the centre of the shower-screen screw with a skewer.
- Loosen the screw counterclockwise with the short end of the Allen key.
- Remove the screw and the shower screen. Note which side faces down. Wash the screen in warm soapy water and dry it.
- Pull out the old seal with your fingers or long-nose pliers. Insert the new seal flat side first, ribbed side facing you.
- Refit the screen and the screw. Turn the screw 2–3 turns by hand, then tighten with the Allen key until flush. Do not overtighten.
- Refit the drip tray and water tank.
Source: Care & Cleaning: Using the Allen key Source: Care & Cleaning: Using the Allen key, p. 27
Used for
Other BES870 procedures
- How to run the cleaning cycleWhen the CLEAN/DESCALE light flashes. This back-flush cycle is separate from descaling.
- How to descaleWhen the CLEAN/DESCALE light stays on (not flashing).
- How to replace the water filterEvery 2 months, more often in hard-water areas. Remove the filter if you use filtered or bottled water.
- How to clean the steam wandAfter every use, and when steam is weak or the tip is blocked.
- How to clean the burr grinderWhen oil build-up on the burrs affects grinding, or the grinder is noisy or delivers no coffee. A blockage between the burrs and the outlet needs the advanced cleaning on page 25 of the instruction book.
Sources
- the Barista Express Instruction Book, BES870 (English, Canadian French and Mexican Spanish edition). Breville Pty Ltd. Document BES870 USCM, revision X20, 2020, 112 pages, en-US. assets.breville.com (PDF). Retrieved 12 November 2026.
Page numbers are the numbers printed in the manual. Where this page and the manual differ, follow the manual.