Review: Dreame L40 Ultra

In just a few years, Chinese company Dreame has become a leader in robot vacuum cleaners, alongside Ecovacs and Roborock, among others. Several of the models can do a lot of things that sound smart on paper. But not all of them deliver when the robot is let loose on the floors of your home.

Among other things, doorsteps, floor separations and correct mapping can cause problems. We have previously tested the top model Dreame X40 Ultra, where doorsteps caused problems. Other robots such as Roborock Qrevo S and Narwal Freo Z Ultra lose contact with the base station or give up halfway and drive ‘home’ to the base.

The Dreame L40 Ultra is equipped with SideReach Extendable Side Brush and MopExtend RoboSwing Technology. Together, these are called Dual Flex Arm Cleaning Technology.

The names refer to a mop and a small arm with a brush that swings out as needed.

This combination is also found in Roborock’s top model, the S8 MaxV Ultra. Which, incidentally, won our duel against the Dreame X40 Ultra in May 2024.

The smart features are not just sales talk, because you get what Dreame promises. In this case, intelligent cleaning in places that would otherwise be difficult to access for a round robot that is 10.3 cm high.

In addition, the Dreame L40 Ultra is able to pause a task. At first glance, this may not sound revolutionary, but in practice it solves one of the biggest challenges of robot cleaning: Nordic homes with doorsteps.

App and setup

The Dreamehome app is the key to cleaning paradise. Scan the QR code under the robot’s cover to download it and connect the Dreame L40 Ultra to your wireless network.

Click on the user icon (a smiley face) to set the language, share the L40 Ultra with others, and enable voice control, among other things. Dreamehome supports all Nordic languages.

The L40 Ultra automatically dispenses cleaning fluid. Use the included 200 ml bottle to fill the container on the left side of the base station behind the front cover. When the bottle is empty, you can buy a litre of Dreame cleaning fluid for approximately £19.99 plus shipping.

Behind the cover is a pre-installed 3.2-litre vacuum cleaner bag. An extra one is included in the box. According to Dreame, bags should only be changed after 75 days of using the L40 Ultra. A pack of six new vacuum cleaner bags costs €32.

Before cleaning, the mops are automatically moistened with water taken from the stand’s 4.5-litre white container. The app has a scale of 32 steps, from slightly damp to wet. If the mops are not needed for cleaning, the robot clicks them off and leaves them at the bottom of the stand.

When the device is connected to the network and online, click on the “Go to device” link on the front page to start the first mapping. Select the icon with a map and a pen to send the Dreame L40 Ultra on its first task.

First mapping

The Dreame L40 Ultra is just as fast as the top-of-the-range Dreame X40 Ultra. My 60 square metre living rooms were mapped in a matter of minutes. The X40 took a few strange detours during its work, while the L40 performs the task without any detours.

The first mapping also encountered the big, recurring problem for robot vacuum cleaners: door thresholds. The Dreame L10 and L20 hated my 2-3 cm high door thresholds, but obeyed and got over them after a few attempts. The Dreame X40 Ultra refused.

Initially, the robot mapped my two living rooms (without doorsteps between them). Then I opened the doors to the adjacent rooms separated from the living rooms by doorsteps and sent the robot off again. To save time, I asked the robot to clean a smaller area near the adjacent rooms.

One of them was my hallway. From a distance, part of the hallway area was captured and partially drawn on the map. On the app’s map, I clicked on the partially recorded hallway and asked the robot to clean there. The L40 Ultra drove towards the hallway. Near the doorstep, I briefly pressed the “pause” button (the on/off icon) located at the front of the robot’s round cover.

I lifted the robot over the doorstep and placed it on the hallway floor. When I pressed the button again, the L40 Ultra not only continued to complete the mapping of the hallway, but also continued the cleaning I had requested.

The method mapped the entrance hall, kitchen and bedroom with adjoining bathroom. Access to the rooms requires climbing 2-3 centimetre high doorsteps. The robot can clear obstacles of a maximum of 2.2 centimetres, so the L40 managed to pass the step between the bedroom and bathroom on its own.

Lifting and moving a vacuum cleaner robot around is not optimal, but it solves the problem of high doorsteps. In this way, the L40 Ultra went where virtually all other robotic vacuum cleaners have given up.

Cleaning in zones and on time

In the app, you can organise cleaning by room, the entire home or by zones. Dreame states that the L40 Ultra cleans in a pattern with straight, orderly rows. I experienced this with the Dreame L10 Ultra and Dreame L20 Ultra. Both tested in 2023.

The pattern that the L40 shows in real-time on the app’s map is sometimes messy and goes across the robot’s “direction of travel”. At first glance, it didn’t result in poorer cleaning when I checked for myself. For example, when mopping. My wooden floors were cleaned just fine anyway.

If your home has multiple floors, the L40 Ultra can create and store up to four different maps. Here you have to lift and move with the robot. L40 Ultra cannot climb stairs. Choose between the maps depending on which floor you need to clean.

Dreame L40 Ultra is one of the few robots I’ve tested that mapped my home correctly. Walls, rooms and carpets were displayed as they really are on the app’s 2D and 3D maps.

You can schedule and queue tasks. For example, cleaning the dining room and kitchen after dinner. However, I tried to get the L40 Ultra to “serialise” cleaning my carpets, but the app ended up deleting the carpets from the map. Instead, I plotted the carpets as zones, which is imprecise and annoying.

Smart cleaning and extra features

The great new feature of the Dreame L40 Ultra is the combination of a flexible mop and brush arm. One mop automatically swings out and cleans where the round shape of the robot can make it difficult for non-flexible mops to reach. For example, close to a moulding along the floor. The function worked flawlessly along my mouldings.

The brush arm can move up and down by one centimetre and has a reach of four centimetres. I tested the function in the bedroom. The sliding doors on my wardrobe don’t go all the way to the floor, but have a shallow gap between the floor and the bottom edge of the doors. It can be difficult to vacuum here, even with a conventional vacuum cleaner.

The robot recognised the small gap. The brush arm shot out on its own and swept all the way to the base of the wardrobe under the sliding doors.

The robot’s built-in LED light switches on as needed. For example, when cleaning under the bed. The AI camera recognises objects and obstacles with varying degrees of success. So a corner of a cupboard is not a wire, even though L40 claims it is.

Conversely, the L40 Ultra doesn’t knock into things detected by the sensors on the side. Although L40 would love to pass between the legs of a bench (to save a detour), there was no room, so the robot gave up and drove around it.

The L40 Ultra kept repeating this manoeuvre, even though the robot should know better next time. Conversely, it memorises carpets and avoids them on its way to other areas. Travelling on smooth floors is faster than passing over carpets and carpet edges.

Carpets are detected by the sensor on the underside of the robot. If the surface is smooth, you indicate in the app whether it is made of tiles or wood, for example. However, you need a steady finger to select from the map’s many small menus and symbols.

You can use the L40 Ultra’s camera and microphone to follow the movements of any pets and talk to them (which I don’t see much potential for). The camera also photographs obstacles that you approve or ignore in the app.

If you have pets (and lots of pet hair), the Dreame L40 Ultra comes with an additional roller brush, the Anti-Tangle TriCut Brush. The roller’s rubber bristles scrape away dirt, while built-in blades cut the hairs so they’re sucked up when the robot’s dust chamber is next emptied.

Emptying from the robot to the base station dust bag is automatic unless you choose to do it via the app. If the base’s sump gets dirty, the app has instructions on how to clean it with the included hand brush. The base station can release clean, warm water into the tub and then suck it up to the dirty water container.

Conclusion

With the Dreame L40 Ultra you get fast and accurate map drawing. The device solves two previously big problems in robotic cleaning: doorsteps and cleaning otherwise hard-to-reach places. The L40 Ultra needs to be paused and reactivated to pass doorsteps, but gets the job done without tying knots or losing connection to the base station.

The robot’s flexible mop and brush arm reaches into corners and very low areas, such as between the floor and the sliding doors of a wardrobe.

I used an Apple HomePod Mini for voice control, but Siri only made the robot tell me where it was. If I wanted to start or finish a cleaning task, Siri told me to continue the task “with the current device”, the robot.

Overall, the Dreame L40 Ultra delivers an excellent experience. However, voice control, obstacle recognition and staying within an assigned zone for cleaning still leaves a bit to be desired.