What an O-ring is and what it does An O-ring is a small circular seal used in various places inside a coffee machine – on pistons, spouts, valves or within the brewing unit circuit. Its job is to create a leak-free connection between two parts through which water or pressurized hot water and steam pass. How wear shows up Over time, the rubber or silicone material loses its elasticity, hardens, cracks or becomes deformed. This shows up as water or coffee leaking from a spot that should be sealed, dripping under the machine, a drop in pressure during brewing, or hissing escaping steam. In some cases the machine signals a pressure fault or stops brewing coffee altogether. When it's time for a replacement Tightening screws will not fix a damaged O-ring – a tight seal can only be restored by replacing it. If the problem is left unresolved, leaking water can cause further damage to surrounding parts or the machine's electronics. How to choose the right part Check compatibility in the product table according to your coffee machine model. Pay attention to which position in the machine the O-ring is intended for, as a single appliance may use several different sizes. Compatible with APPIA APPIA (200610-) APPIA (200811-) APPIA (201103-) APPIA-1GR (200611-) APPIA-1GR (200812-) APPIA-1GR (201103-) APPIA-COMPACT (200802-) + 49 more compatible models APPIA-COMPACT (201103-) APPIA-II-COMPACT (201904-) APPIA 1 GR 2006 APPIA 1 GR 2008 APPIA 2-3 GR 2006 APPIA 2-3 GR 2008 APPIA 2-3 GR 2011 APPIA COMPACT 2 GR 2011 MAC2000 MAC CUP MUSICA (2009-201211) MUSICA (201005-) MUSICA-SILENT-SYSTEM (201507-) PREMIER OPTIMA PREMIER MAXI AURELIA AURELIA II APPIA-II (201405-) APPIA-II (201606-) APPIA-II-1GR (201402-) APPIA-LIFE-2-3GR (201912-) APPIA-LIFE-2-3GR (202010-) APPIA-LIFE-COMPACT APPIA COMPACT 2 GR 2008 APPIA II 1 GR APPIA II 2-3 GR APPIA LIFE 1GR APPIA LIFE 2-3 GR XT AURELIA (200812-) AURELIA-II-COMPETIZIONE (201208-) AURELIA-II-S-V-DIGIT (201208-) AURELIA-II-S-V-DIGIT (201705-) AURELIA-II-T3 (201504-) AURELIA-MCD (201909-) AURELIA-WAVE (201905-) AURELIA 2-3-4 GR AURELIA II COMPETIZIONE 2-3 GR AURELIA II S - V - DIGIT 2-3-4 GR AURELIA II T3 AURELIA WAVE 2019 OSCAR-II (201512-) BEACH ELLI CAFFETTERIA-ITALIANA PROGRAM OSCAR (201201-) OSCAR-MOOD (202208-) PROGRAM VIP Parameters Compatible with APPIA , APPIA (200610-) , APPIA (200811-) , APPIA (201103-) , APPIA-1GR (200611-) , APPIA-1GR (200812-) , APPIA-1GR (201103-) , APPIA-COMPACT (200802-) , APPIA-COMPACT (201103-) , APPIA-II-COMPACT (201904-) , APPIA 1 GR 2006 , APPIA 1 GR 2008 , APPIA 2-3 GR 2006 , APPIA 2-3 GR 2008 , APPIA 2-3 GR 2011 , APPIA COMPACT 2 GR 2011 , MAC2000 , MAC CUP , MUSICA (2009-201211) , MUSICA (201005-) , MUSICA-SILENT-SYSTEM (201507-) , PREMIER , OPTIMA , PREMIER MAXI , AURELIA , AURELIA II , APPIA-II (201405-) , APPIA-II (201606-) , APPIA-II-1GR (201402-) , APPIA-LIFE-2-3GR (201912-) , APPIA-LIFE-2-3GR (202010-) , APPIA-LIFE-COMPACT , APPIA COMPACT 2 GR 2008 , APPIA II 1 GR , APPIA II 2-3 GR , APPIA LIFE 1GR , APPIA LIFE 2-3 GR XT , AURELIA (200812-) , AURELIA-II-COMPETIZIONE (201208-) , AURELIA-II-S-V-DIGIT (201208-) , AURELIA-II-S-V-DIGIT (201705-) , AURELIA-II-T3 (201504-) , AURELIA-MCD (201909-) , AURELIA-WAVE (201905-) , AURELIA 2-3-4 GR , AURELIA II COMPETIZIONE 2-3 GR , AURELIA II S - V - DIGIT 2-3-4 GR , AURELIA II T3 , AURELIA WAVE 2019 , OSCAR-II (201512-) , BEACH , ELLI , CAFFETTERIA-ITALIANA , PROGRAM , OSCAR (201201-) , OSCAR-MOOD (202208-) , PROGRAM VIP