Hum. The stove is usually washed by hand and it will probably not more than once per month in the dishwasher (it is anyway "dishwasher-safe"). Unfortunately, the non-stick coating is far from having given 8 years, as can be seen in the accompanying photo to this comment. My other two stoves (24 and 28cm) bought simultaneously fortunately better aged, but for stoves only two years, they have still been piteous.
To the question "Do you consider the state of my stove 20cm as normal after two years?", Customer service Tefal said "The life of our stoves is a lifetime" estimated ", while depends on the use you make of it. Unfortunately, your stove is no longer under warranty. "
"Buy French", they said! The Swedes, for a lower price, guarantee their stoves made in Italy for 10 years.