Temperature Fuse Unit Pfaff Roller Press
Located on the right hand side under the heating plate cover. Temperature Fuse Unit Pfaff roller press 560/580.
If you're heating sole plate is no longer heating up correctly and what once was steam is now water then the first solution to try is replacing the Temperature Fuse unit.
First class service when I enquired about an obscure part. Received two days later. Very professional company.