We select top-selling window vacs from leading UK retailers and put them through a string of tough tests to find out which are the best. There are several accessories available including replacement pads, belt holders, cleaning liquid and extra battery chargers. Read next: Unibond Aero 360 Compact Moisture Absorber review: an honest review of the budget-friendly dehumidifier alternative How we tested Interchangeable suction heads: Most window vacs come with a 280mm suction head as standard, but many include an additional smaller head for fiddly jobs such as leaded windows and front door panels. Pivoting suction heads can also help to get into awkward spots. Weight and capacity: A kilo may not feel like much at first, but after half an hour of holding the unit at arm’s length it will start to hurt – especially when it fills up with 300ml or so of dirty water. The bigger the tank, the more cleaning you can do without having to stop and empty it, but the heavier it will get. So, tank size is less important than leak-proofing and easy emptying. What extra features and accessories are worth having?

There are several accessories available for the Karcher window vac including replacement pads, belt holders, cleaning liquid and extra battery chargers. It comes with two interchangeable squeegee heads, which can be detached from the suction nozzle for cleaning after use. These heads measure in at 18cm and 28cm. Both feature the new lip technology to allow for upper-edge cleaning to the ground without interruption, to achieve a streak-free finish. So, what can the window vac be used for? Well obviously, the main use is for cleaning windows but in our experience, it can also be used for cleaning shower doors and removing condensation from surfaces. The window vac is extremely versatile and we found it particularly useful for cleaning up liquid spills but you may find it handy for other applications. In fact, it will perform great on all smooth surfaces. What’s in the box? I sprayed a generous amount of the cleaning solution over the window, then working the Karcher window vac vertically down the pane. I started with the smaller squeegee head, but later switched to the larger one to cover more surface area at once.The set consist of 2 extending poles; one for the window vac and a separate one that has a washable cleaning head attachment. Each pole is 1.2 metres in length but can be extended to 1.9 metres. Your Karcher window vac can be securely mounted on the base plate and attached with the rubber strap. The set consists of two extending poles; one for the window vac and a separate one that has a washable cleaning head attachment. Each pole is 1.2 metres in length but can be extended to 1.9 metres. Your Karcher window cleaner can be securely mounted on the base plate and attached with the rubber strap. I have to say I was impressed by the results. Surprisingly, I didn't have to repeatably go over the area with the spray bottle, and the squeegee blade wiped away all of the diluted concentrated cleaning liquid to reveal a shiny surface – with no water marks to be seen. I sprayed the cleaning solution on the harder-to-reach areas of the shower screen first, then turned on the window vac. I moved in a vertical direction and could see the buildup (almost) vanish. This was a great result.

We judge how comfortable each window vac is to hold and empty. We also do this wearing Cambridge Simulation Gloves – a piece of kit that helps replicate the experience of users who suffer with limited hand movement. Another good use for the window vac is cleaning up liquid spills from hard floor surfaces, such as laminate, tiles or hardwood flooring. For this test, we simply poured water on the laminate/tile floor surface and the window vac handled this with ease. Again the surface was left clean and streak-free but we were surprised to find that the floor was almost entirely dry to the touch. I had high hopes for the Karcher Window Vac WV 6's cleaning performance. I live in an old house with high ceilings and, therefore, have numerous tall windows to clean.We recommend that when cleaning up dirty water or other liquids, such as milk for example, then you should remove the water collection bottle from the main unit to give the bottle a good rinse out to stop it from smelling the next time you use it. The Karcher WV2 Plus Review: In summary Mel said: “In the mornings in the winter, because we're not double glazed, the water is running down our windows and it's obviously going to damage the paintwork. With this, I can vacuum all of it up. It’s brilliant and it doesn't take very long.”