Under consumer law, youre covered for 6 years providing youve not misused the product you have purchased.
This means should you encounter a defect within this time you are entitled to a replacement model or free repair.
Its basically covers items that 'should' be expected to last for this amount of time.
The sale of goods act/fit for purpose. So, knowing this, go buy your Karcher, safely in the knowledge that should it go wrong, youre entitled to a replacement or free repair!! Hope this puts your mind at rest!
https://www.inbrief.co.uk/consumer-law/warranties/