Use the machines like you should.

I am totally happy with my karcher products, both the Yellow machines (for household use) and the Grey coloured machines (for business use). I look after my vacuum cleaner filters as I am supposed to, and only use my yellow pressure washer at home for a max of 1 hour per week, as intended. People tend to use the yellow machines for business use and then jump up and down if it is not covered by warranty when parts wear out, due to frequent use.