Meet the Other Phone. Flexible and made to last.

Meet the Other Phone.
Flexible and made to last.

Buy now

The Mumsnet guide to Kärcher Window Vacs

For clean, smear-free windows at the touch of a button, the Kärcher Window Vac is Mumsnetters' go-to product. But what makes it so great? Read on for everything you need to know.

By Poppy O'Neill | Last updated May 13, 2025

Our writers test and research products independently. When you buy through a link on our site we may earn a commission, but we’ll only ever publish an honest review. Find out more.

Karcher window vacs

As proven time and time again, Mumsnet users love a Kärcher Window Vac. Whether they're using it for cleaning windows, sucking up spills or clearing condensation, they say it's a handy piece of kit to keep around the house. Although it really had its heyday a few years back, Mumsnet users are still keen, with Kärcher window vacs the most-mentioned and most-recommended.

We have the karcher window vac, it's great. Use it every morning in the bedrooms.- mollydol

"I have had a karcher window vac for years and all the accessories. Including the wee squeegee thing to clean window before vac. I used it today for the first time. Amazing. And quite fun. (I don’t own the company)." - IBelieveinSomething

Whether you're considering buying one or already own one and have some questions, read on for some tips and tricks on how to get the best out of your Kärcher Window Vac.

Woman using a Karcher window vac

What is a Kärcher Window Vac?

Kärcher's Window Vac pretty much does what it says on the tin – it vacuums up excess moisture. Among other things, this makes it really handy for helping when you decide to clean windows, shower panels, mirrors, or any other smooth, flat surface in your home.

Although the vac doesn't do the cleaning for you (and therefore does still require a bit of elbow grease), it definitely makes cleaning much easier – sucking away the excess water so it doesn't pool on the surface below. It also means you won't have to wring out or dry anything.

Plus, it can be used to clean up the inevitable drinks spills and bathroom tidal waves which come hand-in-hand with a house full of smaller people.

How do you use a Kärcher Window Vac?

All it takes is giving the surface a good soaking with water and your cleaning product of choice (Kärcher do produce their own cleaning solution, but Mumsnetters swear washing up liquid does a pretty good job, too), a scrub with a microfibre cloth or similar, then a swoosh around with the window vac to collect up all the water. And, hey presto, you'll have shiny, clean (and hopefully smear-free) windows.

You can achieve clean windows, mirrors, shower glass and even floors in four simple steps:

  1. Spray your chosen cleaning solution all over the surface

  2. Wipe the surface thoroughly with your cleaning cloth

  3. Use your window vac to remove all the suds and water left behind

  4. Once full, you can simply empty the water straight down the sink

Kärcher Window Vac accessories:

There's also a whole host of added extras and replacement parts ready to purchase. Some of them only work with certain models, so make sure to check this before you buy.

Replacement parts:

Extra accessories:

What do Mumsnetters like about Kärcher Window Vacs?

With grand testimonies including the one from the Mumsnetter who wanted to set up a window cleaning business just so she could use her window vac more often, what is it specifically that our users like so much about this bit of household tech?

"Karcher window vac has changed, if not my life, my attitude to cleaning windows.
It's changed window cleaning from the task I dreaded most to one I almost enjoy. Now it's so quick to do and the windows actually look better! Before they used to look worse half the time because I couldn't get rid of smears.
Other window vacs are, doubtless, available." - LaMarschallin

"We have a Karcher window vacuum, which I use on the windows (and the bathroom tiles after showers), and it’s amazing to see how much water it takes in. I’d suggest getting one as it’s more efficient than wiping the water up with a cloth." - EllieQ

"+1 to the Karcher window vac (cheaper window vacs are available), we use one daily on some old double glazing in the bedroom as it gets covered in condensation overnight, especially in this weather." - hardworkandabitofluck

What do people also ask about Kärcher Window Vacs?

How do I stop smeary streaks from being left on my window?

One of the things Mumsnetters like most about their window vacs is the fact that they leave surfaces smear- and streak-free. Occasionally, however, you can still be left with some smudges even after using the window vac. If you're getting less-than-perfect results, try wiping down the blade more regularly.

How often does the Kärcher Window Vac need emptying?

One of the main pros of a Kärcher Window Vac is that you can just empty the water straight down the sink when you're finished, rather than having to wring out a cloth over and over. The capacity of all Kärcher Window Vacs is between 100ml-150ml, and the amount of time this will take to fill will depend on how much liquid you use on each surface. If you're mopping up spills, it's more likely to fill up more quickly.

What cleaner or detergent should you use with a Kärcher Window Vac?

Although Kärcher do have their own cleaning solution, Mumsnetters also recommend that you could also use any of the following:

  • Washing up liquid

  • White vinegar (diluted)

  • Dedicated glass cleaner (such as Flash or Windolene)

What's the difference between the different Kärcher Window Vacs?

The specifications of your Kärcher Window Vac will vary greatly depending on which model you choose. All models have their standard suction nozzle, a tank for the dirty water, and an LED battery display, but as the models get more advanced you get more features – like re-chargeable batteries and varying nozzle widths.

1. Kärcher Window Vac WV1

Being the most basic model, the VW1 still does the job nicely, but without some of the bells and whistles the other models boast. Thanks to its cheaper price point, it's your best bet if you're a window vac novice, but be warned: only having the one blade size can be quite limiting. In the box, you get the window vac itself and the charger as standard.

Specs:

  • Vacuum nozzle width: 250mm

  • Capacity: 100ml

  • Battery run time: 25 minutes

  • Battery charge time: 100 minutes

2. Kärcher Window Vac WV2 Plus

The best thing about this model is that it comes with the Kärcher spray bottle, complete with a microfibre cloth. Fill this with whatever solution you want (or the handy sachet of Karcher cleaning fluid also provided), and spritz it all over your window before vac-ing it all off. It's also slightly more premium than the first model thanks to it's quieter technology and longer-lasting charge. In the box, you'll also get your charger, spray bottle, and cleaning solution sachet as standard.

Specs:

  • Vacuum nozzle width: 280mm

  • Capacity: 100ml

  • Battery run time: 35 minutes

  • Battery charge time: 185 minutes

  • Averages at 35 windows per charge

3. Kärcher Window Vac WV5 Premium

Instead of recharging the unit, the WV5 model comes with a detachable, rechargeable battery, giving you the option to buy more than one and get longer uninterrupted use. And even more importantly, the model comes with two different nozzle sizes: the standard 280mm plus a smaller 170mm, perfect for the smaller panes of glass and mirror. There's also a three-stage LED battery indicator, meaning you've got plenty of warning before you run out of battery. It comes with a standard suction blade, narrow suction blade, spray bottle, cleaning solution sachet, lithium-ion battery, and charger.

Specs:

  • Vacuum nozzle width: 280mm and 170mm

  • Capacity: 100ml

  • Battery run time: 35 minutes

  • Battery charge time: 185 minutes

  • Averages at 35 windows per charge

4. Kärcher Window Vac WV6 Premium

By far the sleekest-looking model, the WV6 Premium is the cream of the crop. With a display showing the number of minutes of charge left, silicone lip technology, and a larger dirty water tank, it's definitely the easiest to use and the best bet if you're going to use it a lot. It comes with a whole host of extra accessories, too – including a quick charger, outdoor microfibre wiping cloth, dirt scraper and interchangeable nozzles, as well as the spray bottle and sachet of cleaning fluid.

It's important to note that, unlike the WV5 Premium, the battery on this model is not detachable.

Specs:

  • Vacuum nozzle width: 280mm and 170mm

  • Capacity: 150ml

  • Battery run time: 100 minutes

  • Battery charge time: 170 minutes

  • Up to 215 windows per charge

About the author

Poppy O'Neill is a Content Editor at Mumsnet and a mother of two. She researches and reviews the products Mumsnetters swear by, with a particular focus on home essentials, laundry and fans. From a highly-recommended retractable washing line to the best quiet fans money can buy, and Mumsnet's favourite dehumidifier to the steam generator iron that'll cut your ironing time in half, she loves to deep-dive into research and find the very best products on the market.

With an MA in Creative Writing and a PGCert in Lifestyle Journalism, Poppy's written about parenting topics for The Sunday Times, The Guardian, The Mirror and The Sun. She's a best-selling, award-winning author, and her books for children and parents have been translated into 12 languages.

About Mumsnet Reviews

All Mumsnet product reviews are written by real people after extensive research and testing. We work hard to provide honest and independent advice you can trust. Sometimes, we earn revenue through affiliate (click-to-buy) links in our articles. However, we never allow this to influence our coverage.