I've heard stories of this happening and the cost to repair can be as much as the price o a new machine. Having said that, my little K2.02 still plugs away fine.
See what Karcher say and do. Where did you buy it from?
Despite my karcher working, I upgraded and i went for nilfisk too. If you do go for the latter, buy it from Argos so any problems and you just take it back in person.