I have just bought my husband a Karcher K4 complete control pressure washer to replace his 20 year old defunct one which gave up the ghost. . It was supposed to be for Christmas but it arrived and he saw it!

I got the K4 because I thought it was the better one - reading reviews. Now OH tells me it cannot be used on a mains supply because it is too powerful. Is this true?

I didnt get it to use on a ruddy water butt. I intended it to link into the outside tap where we currently have the hosepipes connected.

Why do none of the review sites or even the information about the K$ state it cannot be used on domestic supplies? OH read it in the instructions ( yes it does say " cannot be used on the water net") . So, can it be used or not?