My machine is about 2 years old and I use it 2x daily. My steam knob has always been hard to turn, gets very tight and sometimes gets stuck on or off. Now, it just turns freely, does not tighten or stop and does not control the steam wand, so I can not froth milk or set the steam wand to leak when warming my machine up. Is this simply a matter of ordering a new knob and replacing the plastic part, or is it more complex? Is this a common problem for the Oscar? Thanks!

Coffee Makers & Espresso... - Nuova Simonelli - Oscar Coffee Maker, Espresso Machine