My karcher window vac, has a rapid flashing red light when switched on and doesn't work

Check the hoses for clogs due carpet fibers.

If you contact one of the Karcher Centers ( details are on Karcher.co.uk website) they may be able to help.
regards Gary

Have you tried to take it all apart just a small bit of rubbish will stop it from working.

Hi. I've just bought the karcher window vac wv50 & am having the same problem finding the serial No. I presume you want to register your product for the guarantee to be valid. I went online Karcher.co.uk & registered mine. You will note that when doing so it does not ask for a serial number but a model No. This is found on the side of box you got the item in (mine is just above the barcode) & it reads something like; 1.633-113.0. Hope you still have the box!

Take it apart and see what is stopping it (the motor) from turning .

Take it to your local vac shop for repair. Depending on what model you have, it may have a bad switch or you brushroll ends could have failed. Both are common issues.

I had the same problem and I let the battery run down to stop it cycling on and off. My husband investigated it and found that there is a fault with the on board battery charge sensing circuit. (when the charge is about 10 to 15 % remaining the onboard ic controller cycles the unit on and off, irrespective of the switch. He checked it by cutting wires to the switch and it still cycled off and on so the switch was not faulty.
He put it all back together and said to charge it before it gets too low. If it cycles on and off it probably needs a re charge at that point.
Unfortunately there is no battery level indicator on the tool and nothing to suggest in the manual of what may happen when battery is flattening.
I am taking this up with Karcher as I only used it three times so far and it it was not a cheap gadget. Hope this helps

needs new battery get one here http://www.buyspares.co.uk/karcher/window-cleaner/window-cleaner-battery/product.pl?pid=1227185&shop=karcher&path=68315

go to http://www.dyson.com/
get the support and download the model, troubleshooting, video for your trouble.

God bless you

It cost me $65, had to buy a new clean water bucket. If you shine a light on the bottom you will see a shatter effect much like broken shatter proof glass in car windows, apparently it is cheap and doesn't last. Who knew?