Karcher K4 pressure washer

This appears to show it being used from the mains:

What it actually says is "the appliance must never be used on the drinking water net without a system separator."

Which sounds like Karcher-speak for "should have a double check valve on your garden tap" but you should have one anyway.

Maybe they are covering themselves when all the streets water pressure drops when its in use grin. Brian

But after" cannot be used on the water net" it goes onto say "without a system separator". EN 12729 Type BA .

Water net I would hazard a guess means the mains water supply in a not too perfect translation from German . The costly EN 12729 Type BA devices that can be purchased to enable legal connection may be a German regulation. Here I would just make sure the tap you intend connecting it to is a reasonably modern one that has a double check valve arrangement built into it or fit one in the supply pipe. That is what the 1000's of other people who buy pressure washers in the UK will be doing. If you are still worried that may break regulations arrange for it to draw water from a butt but have a hose filling it about the same speed as you are drawing water from it, could even use a large flow ball valve arrangemet in the butt to do that automatically on the feed. Water Butt about £35 . Float valve around a tenner , tenner for sundries, total about £55 .

Backflow preventer as suggested by Karcher manual , Around £450.

Don't think many people wll be going that route.

OTOH is your other half concerned that you actually have too low a water pressure to supply the machine anyway? If so just use the water butt method and accept that periods of rest may need to occur while it fills up again.

G.Harman

G.Harman

He's talking rubbish. All pressure washers will work off mains supplies.

Just checked, I have a K4. Apart from being a piece of overpriced crap which is far inferior to the old Karcher of 20 years ago, it works from mains.

Thanks to everyone for the replies. I have informed my husband it probably means a non return valve ( which we already have). He nodded. I suspect he was just trying to upset me because I bought the pressure washer for him without asking him first.

Maybe he felt the same way as some women would if presented with a new iron or hoover to replace their old, knackered one. Especially as a Christmas present?

That Santa is a complete bastard delivering the present in November.

Why don't you nip off down to a Ann Summers store and buy some sexy underwear and give your husband a proper Christmas present to unwrap?

I have a k4 and it works perfectly from the mains water.

Bill.

Not because it is too powerful but because the water companies don't like you connecting things that can potentially pump chemicals back into their drinking water supply network if things go wrong.

I think you will find it actually means that you should have a non-return valve in the path to the tap (and that will have been true of your previous one too). It is to protect the mains water supply from blowback of industrial detergent into the supply.

There are cheaper ones - this was the first I found online. Mine is a Hozelock.