From grey to white – a clean carpet thanks to Kärcher’s SE 4001

Recently, we wanted to have our living room carpet cleaned. After five years, all sorts of dirt is likely to have settled in it – despite regular vacuuming. My inquiry with a carpet cleaner went nowhere. They weren’t cleaning carpets at the moment. Strange business model for a carpet cleaner, I thought to myself. Still, a solution for the carpet had to be found.

If no professional wants to do it, I’ll have to handle it myself. And so a test device from Kärcher soon arrives at the door: the SE 4001.

CH version

Industrial vacuum cleaners

Kärcher Se4001

Wet dry vacuum cleaner

89

Industrial vacuum cleaners

Kärcher Se4001

Wet dry vacuum cleaner

89

EU version

Industrial vacuum cleaners

Kärcher Se4001

Wet dry vacuum cleaner

169

Industrial vacuum cleaners

Kärcher Se4001

Wet dry vacuum cleaner

169

A combination suction and spray hose

Inside the cube-shaped box, I find the yellow Kärcher carpet cleaner, which also doubles as a vacuum. And any real vacuum needs to have one thing over all: nozzles. Many of them. For upholstery, grout, hard floors, carpets. But I’ll leave those to the side for now. I want to clean a carpet, for which I’ll need to connect two things. Firstly, the spray hose. With it, the SE 4001 sprays tap water mixed with detergent onto the carpet. Secondly, the suction hose. It sucks the now dirty water away again. I connect the thin spray hose and thick suction hose with fastening clips. This is smart because it means less cable and hose clutter. I plug both hoses into the slots on the device, where they click into place noticeably and audibly. At the other end of the hose construction, I mount a handle and two suction tubes inserted into each other. Nothing snaps into place here, so I’m not sure if I put it together tight enough. Eh, it’ll probably hold.

Still, the thing that turns the SE 4001 into a carpet cleaner is missing: the spray-ex floor nozzle. It reminds me of the wiping unit on a Kärcher window cleaner. And it also works in a similar way. It sprays detergent onto the carpet with a nozzle. It then sucks that right back in through a narrow gap and collects the dirty water in the unit.

What is the spray extraction process?

This method is called spray extraction. Basically, it’s the working principle of a washing machine transferred to a new device. After all, most carpets won’t fit into a washing drum. A spray extraction machine sprays the cleaning mixture onto carpet fibres at high pressure. In the process, light soiling is already loosened. In the case of stubborn soiling, a soaking phase for the cleaning agent is recommended. Subsequently, the cleaning liquid with the dirt is extracted directly from the carpet again, i.e. vacuumed. The process thus avoids dirt dissolved by a cleaning agent simply being brushed further across the carpet, for example. Up to 90 per cent of the liquid should be extracted, so that the carpet retains little residual moisture and can be quickly dried and used again after treatment.

Spray extraction carpet cleaning is definitely more effective than vacuuming. No matter how powerful your machine is, it usually doesn’t get the dirt that’s deep down in the carpet. The higher the pile, the more serious the problem. Over the years, a veritable layer of dirt can form in the carpet.

How much detergent should be in the water?

I can manoeuvre mySE 4001 like a pro thanks to six rollers. Together with the cable, which is over five metres long, it’s very mobile. After just under half an hour, assembly is done. Now, however, the Kärcher instructions present me with my first puzzle. Among the accessories I find a sample of the carpet cleaner. Nice. Looks like the bottle I bought separately will remain closed for now. Only, what’s the right mixing ratio? How much water should I add to the 100 millilitres of detergent? The instructions only say «Fill with tap water, do not overfill». Not helpful in the slightest.

Checking with Kärcher provides the answer. I should fill the fresh water tank completely. This apparently achieves the correct mixing ratio. Alright, I top up with just under four litres of fresh water. I use a PET bottle to grab it from the tap, the removable fresh water tank doesn’t fit in the sink.

Best results at a 45-degree angle

When it comes to carpet cleaning, teamwork is the name of the game. My wife helps – mainly so I can take photos for this test report. We decide not to go full out right away. On a cheap carpet from everyone’s favourite Swedish furniture store, any damage from misapplication would be tolerable. The carpet is flat weave, has collected a few stains over the years and has greyed undignified.

Before you start, take a look at the instructions again. We try to decipher the engineering lingo. We’re to close the secondary air slide, press the switch for spraying (position I), put the switch for suction in position I. Putting three switches in the right position – we just about manage that.

There’s a small lever on the spray handle. If you pull it, it sprays the cleaning agent onto the carpet. As that’s supposed to happen before vacuuming, I put the spray-ex floor nozzle on the carpet and pull it toward me. Thus, the carpet is first sprayed and then vacuumed. After a few lengths, I understood what was important. At an ideal 45-degree angle, the nozzle develops the strongest suction force.

Wet cleaning isn’t even that wet

The Ikea carpet measures six square metres. We wet clean it in about 20 minutes. The consumption of cleaning mixture is difficult to estimate, especially at the start. Are we spraying too much? Not enough?

In the end, we sprayed on about three litres and sucked most of it back up. The result is something to behold: the device’s water tank contains a grey-brown witch’s brew. Behold, what a normal vacuum cleaner can’t get out of a carpet.

The amount of water that wasn’t reabsorbed leaves the carpet slightly damp. It must dry outside. There must be a good litre and a half of water still in the carpet, as I only have about a litre and a half of dirty water in the tank. Consequently, there’s still considerably more residual moisture in the carpet than would theoretically be possible with spray extraction. Best avoid leaving the freshly cleaned carpet to dry on a wooden parquet floor.

The spray-ex nozzle fails in deep grooves

After the first carpet, we venture to the second, one from our daughter’s nursery. It’s a short-pile carpet. Woven-in images of animals ensure that it isn’t flat, but features small valleys where the colours of the carpet yarn change. Here, the SE 4001 reaches its limit. Although we now have a good handle on the 45-degree angle, spraying and vacuuming several times, lint and dirt remain in the carpet.

Theoretically, there are two ways to clean a carpet with the SE 4001. Either in one go, spraying and directly vacuuming again. Or you can just spray first, applying the cleaning liquid to the carpet. After an exposure time of at least five minutes, you then begin sucking.

In practice, we haven’t noticed any difference whether one or the other type gives a better result. However, none of the carpets had stains that I’d put in the «heavily soiled» category either.

Verdict: spraying and vacuuming over just a hoover

First things first: the SE 4001 gets carpets clean. I wonder if they’d rival a professional carpet cleaning? I don’t think so. But for home use, the Kärcher device is definitely worth it. The material is solid plastic, cleanly manufactured. The connections are tight, nothing wobbles or rattles. I struggled with the user manual a few times. It was clearly written by someone who already knows the device well and can’t imagine what it’s like to use it for the first time. Kärcher still has room to grow here.

Some things are irritating in practice. When the detergent tank is empty, the pump simply runs dry and I’m supposed to take the noise as a sign to refill. The water tank is removable, but it’s just too bulky for some sinks to refill then and there.

The fact that the SE 4001 is also a pretty powerful vacuum cleaner is nice. Before you clean a carpet, you can free it from coarse dirt. Converting to a carpet cleaner is much faster than assembling the unit first.

In our household, it still won’t replace Dyson’s useful battery vacuum cleaner, however. However, it’s suitable for vacuuming in a car. Or for sucking up liquids. That’s where it’s an undisputed champion.

Just under 250 francs is a good investment if you want more cleanliness than is possible with vacuuming. I’ll clean our carpets once a year using the SE 4001. It’ll also save me from inquiries with carpet cleaning companies that are currently unwilling or unable to clean carpets. Of course, this isn’t meant to be a blanket judgment against all carpet cleaning companies. During my research, I also learned that these companies use even more capable machines and how much effort goes into professional carpet cleaning when done right. But that’s a story for another time.