iRobot Roomba Plus 405: This mop-vacuum combo left us unimpressed

We found this all-in-one cleaning robot to be not very good at anything

The iRobot Roomba Plus 405 is a combination mopping-and-vacuuming robot with a self-emptying, self-washing dock. It’s positioned as a midrange model for consumers who want an all-in-one robot vacuum and mop but who are willing to forego the most advanced technologies of high-priced flagship models. 

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However, based on our tests, the Roomba Plus 405 was a disappointing performer that’s bested by lower-priced rivals in almost every category. Below, we take a look at the BestReviews Testing Lab’s findings and give you the lowdown on a couple of robot mops that we do highly recommend instead. 

In this article: DREAME L50 Ultra Robot Vacuum and Mop and DREAME L10s Ultra Robot Vacuum and Mop

Testing the iRobot Roomba Plus 405  

The BestReviews Testing Lab strives to investigate every claim a brand makes about its product. For this article, we tested the Roomba Plus 405 in a 1,000-square-foot two-level apartment with a mixture of hard vinyl-plank flooring, low-pile area rugs and wall-to-wall medium-pile carpet.

To test the Roomba Plus 405, we set up our test unit according to product instructions, noting ease of assembly, app download and Wi-Fi connections. We then ran the test unit on several whole-floor, room-by-room and zone-based cleaning jobs. We noted:

• Vacuum performance: We used specific tests with 1 tablespoon each of dry rice, dry oatmeal and baking soda to test vacuum strength and dirt pickup on both hard floors and carpets. We also used 1-to-2-inch bits of faux fur to simulate pet hair on hard flooring and carpeting.
• Mopping performance: We noted how the robot cleaned up a spill of 1 tablespoon of water, as well as how it did on residue from the vacuum tests and on old stains. We also noted how often it washed its mops, if it spread used water, and if it effectively avoided dampening rugs and carpets during general cleaning.
• Navigation and mapping: We noted how long it took to map our test space, how accurate the map was, how smoothly it could navigate from room to room and to specific zones, and if it recognized and avoided obstacles well.
• Design and dock: We took note of the size and design of the dock, how it was set up, how effective it was at self-emptying and mop washing, and how loud it was in operation.
• Software and user experience: We evaluated how easy it was to start a cleaning job from the app, if needed controls were easy to access and how much information we could get at a glance from the Roomba at Home app.

Finally, we compared our findings about the Roomba Plus 405 to previously tested robot vacuums and to rival models on the market to determine value for money and overall recommendability.

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The big picture

We were disappointed with the performance of the iRobot Roomba Plus 405. It could not vacuum well, was a mediocre mop and had obstacle-avoidance and app usability issues. Lower-priced models are more effective cleaners, and there are more reliable models in its price range.

How to use the iRobot Roomba Plus 405

Setting up the Roomba Plus 405 is straightforward for anyone used to robot vacuums. A diagram card included in the packaging gives the basic steps. The dock is assembled with the clean- and dirty-water tanks and the landing foot pad. The clean-water tank is filled with clean water. The robot itself needs its mop pads snapped into their hubs, but otherwise has little packaging to remove.

A QR code helps the user download the Roomba at Home app, which guides them in initial setup. Resetting the robot and pairing it to Wi-Fi took less than five minutes and remained solid the entire testing period, an improvement over earlier tested Roomba models.

A mapping run is the first suggested task in the app once the robot is paired. The initial mapping run was rudimentary during testing, and it required a certain amount of editing afterward. There was no automated intelligent division of the map into rooms nor was there automatic labeling of flooring type.

Cleaning sessions are activated from the app, and cleaning routines are suggested in the main page based on previous sessions, such as single-room vacuuming, zone deep-cleaning and so on. Whole-floor mopping and vacuuming isn’t suggested unless it’s frequently used, so you have to dig for that option if it’s not suggested. The robot supports multiple floors, but like most robot vacuums, must be physically placed on a different floor.

Cleaning jobs can also be activated via voice assistant, although the Roomba only works with Siri Shortcuts to activate specific jobs as opposed to full Matter/Homekit compatibility.

Maintaining the robot involves flipping it onto its back and checking its roller brush, wheels and side brush for leftover dirt and tangles. All the moving parts are easy to remove and replace. The dirty-water tank should be emptied frequently to prevent bad odors.

The Roomba Plus 405 requires some babysitting to make sure it doesn't get tangled in cords. Removing as many obstacles as possible prior to a cleaning job is recommended.

iRobot Roomba Plus 405 benefits

• All-in-one cleaning: The Roomba Plus 405 combines vacuuming, mopping, self-emptying and self-washing in a single unit.
• Fast mapping: The Roomba Plus 405 uses LiDAR to quickly map a room or floor and navigate its way from room to room.
• Persistent cleaning zones: Cleaning zones can be drawn in the Roomba at Home app and persist from cleaning to cleaning just like rooms; these zones can be paired with rooms or other zones in a single cleaning job.
• Pet hair on hard floors: On smooth hard flooring, the Roomba Plus 405 successfully removed 90% to 95% of faux fur used to simulate pet hair in our tests.
• Deep cleaning: Activating deep-cleaning mode makes the Roomba Plus 405 scrub in diagonal back-and-forth movements, capable of removing tough stains from hard flooring.

iRobot Roomba Plus 405 drawbacks

• Poor carpet performance: In standard mode on carpet, the Roomba Plus 405 could not pick up medium- to large-sized particles in our tests, struggled to remove even 50% of faux fur on carpet and left around 50% of small particulates on carpet.
• Poor object recognition: While capable of detecting and avoiding obstacles placed in its path, the Roomba Plus 405 could not recognize obstacles like cords. It tangled itself twice in a single cleaning run and needed human assistance to free itself.
• Mediocre mop performance: The Roomba Plus 405’s spinning mop pads could not lift old stains from vinyl plank flooring without activating deep-clean mode, and spread spilled water around rather than absorbing it.
• Noisy: At 80 to 85 decibels, the self-empty function of the Roomba Plus 405’s dock is quite loud. It also makes notable scraping noises on uneven flooring while on a cleaning job.
• User-unfriendly app: The Roomba at Home app has a rudimentary map display and an unintuitive nested series of commands with confusingly located controls.

Should you get the iRobot Roomba Plus 405?

The iRobot Roomba Plus 405 is a mediocre robot vacuum. While it has many of the features of a good combination vacuum-mop robot with an autoempty dock, it isn’t a very good vacuum, and its mop is unspectacular unless you activate the loud, long deep-clean mode. Even on sale, its poor overall performance makes it not recommendable. It’s better than nothing, but that isn’t saying much. 

Robot mops we recommend 

DREAME L50 Ultra Robot Vacuum and Mop 

Though this mopping robot is pricier than the Roomba Plus 405, it’s worth it. Our top choice impresses with its 19,500 Pa of suction that picks up debris and hair from every nook and cranny and an extendable side brush and mop that gets into hard-to-reach spaces. It even knows when to pay attention to the dirtiest areas without any input from you. 

This is one robot mop you’ll rarely need to check on. In a single step, it can climb over thresholds up to 1 and a half inches high and, in two stages, it can pull itself over anything in its path up to 2 inches and keep on going. Its advanced AI-powered object recognition helps it avoid more than 180 common household objects, including cables. Plus, it rinses and dries the mop pads for you and can hold up to 100 days’ worth of debris in its dock.   

DREAME L10s Ultra Robot Vacuum and Mop

For a feature-packed and budget-friendly robot mop and vacuum that’s about the same price as the Roomba Plus 405, consider the Dreame L10s Ultra. A solid performer, its mopping pads spin at 180 rpm for the most thorough scrubbing. And when its done, it self-cleans and dries the pads for you. 

It uses AI navigation to quickly learn your home, so it can tackle high-traffic areas more efficiently. Offering 5,300 Pa of suction and a single brush roller, it won’t give you the same deep clean as the L50 but is still excellent for daily light pickup. Its 3-liter dust bag can last up to 60 days before it needs to be emptied, and it can cover 2,152 square feet with its 2.5-liter water tank, saving you time and energy.   

 Check out our full guide to robot mops with a complete list of all of our favorites.

Prices listed reflect time and date of publication and are subject to change.

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