iRobot’s Roomba Plus 405 Combo robot vacuum represents the refresh of its Roomba lineup. They have since moved to LiDAR navigation systems as opposed to VSLAM and to more standard spinning mop pads, which have become very popular in recent years. We had high hopes for the 405 and this refresh in general. But after we bought one and evaluated it extensively over several weeks, it was a letdown. And you’ll learn all about our findings in this Roomba Plus 405 Combo review.
Not only did it not make the Vacuum Wars Top 20 list (which is rare for a new release like this), but it didn’t even reach the top 60.
iRobot Roomba Plus 405 Combo
· avg tested 2.60
The iRobot Roomba Plus 405 Combo offers reliable basic debris pickup with its single roller brush, an auto-wash dock, lift-up mop pads for mixed-floor cleaning, and precise LiDAR navigation. However, it earned a low 1.41 Vacuum Wars Overall score after falling short in several important testing categories. Suction and airflow were below average, while its carpet deep-clean and pet-hair pickup results were the poorest Vacuum Wars had recorded at the time of testing. Its single water setting also left floors excessively wet, and the robot lacks modern obstacle-avoidance sensors. A still-buggy app further limited the overall experience. See additional info
The Basics: Roomba Plus 405 Combo
The 405 is a robot vacuum mop combo with an auto-wash dock for washing and drying its mop pads and refilling its water tanks. It also has two spinning mop pads that lift whenever the robot senses carpets to avoid getting them wet.
This model is meant to be iRobot’s mid-level, budget-friendly option with many features, but not its flagship.
In our Roomba Plus 405 Combo review, we’ll compare it with its most logical competitor, the MOVA P10 Pro Ultra. Both products have the same list price and sell for about the same retail price. The P10 Pro Ultra recently became our best-value pick, so it’s also a good way to show the extreme differences in value between the two.
Mova P10 Pro Ultra
Vacuum Wars Stars 3.59 · avg tested 2.60
The Mova P10 Pro Ultra stands out as a strong mid-range contender. Its 13,000 Pa turbocharged suction and multi-level LiDAR mapping handle dust, debris, and pet hair on hard floors and carpets, while the all-in-one dock automatically empties the bin, refills water, adds cleaning solution, washes and heat-dries the mop pads, and self-cleans its washboard. The mop lifts 10.5 mm to stay clear of carpets, and an RGB camera plus 3D structured-light sensor can recognize up to 70 obstacle types—even in low light. With a FlexReach extending side brush for corners, pet-care monitoring, and “Hey MOVA” voice control, the P10 Pro Ultra delivers flagship-level conveniences at a mid-range price—making it a compelling option for mixed-floor homes and pet owners. See additional info
Evaluation and Performance
Let’s start with the good stuff because there were quite a few things that the Roomba Plus 405 Combo did well.
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Debris Pickup
This robot vacuum used its single side brush and single main brush in a floating brush housing effectively to sweep up debris from the surfaces of hard floors and carpets. It picked up everything from fine debris to extra-large debris on both surface types without scattering or other issues. So, for its most basic job, it was more than adequate.
Single Brush Roll
For the first time ever, iRobot went with a single brush roller for their new lineup.
This is a move from the dual brush rollers they pioneered and patented 20-plus years ago. The single roller was better than the previous rollers at resisting hair tangles.
In our 7-inch hair tangle evaluation, only 17% of the hair was tangled in the roller compared to about 50% with the dual brush rollers.
Docking Station
…overall, the auto-wash dock was a pro for the price and is a significant upgrade from previous iRobot self-washing docks, which have not been highly rated.
Another good thing is the new auto-wash dock design. When the robot returns to its dock to recharge, it will empty the contents of its dust bin into the included disposable bag within the dock. iRobot says it will last 75 days before needing to be changed out. The dock will also wash and dry the robot’s mop pads and refill the robot’s water tanks.
It has a removable tray at the bottom for manual deep cleaning, which is nice, and generally, the dock functioned well during our evaluations. However, it was a little louder than average during the emptying process.
Also, the docking station is missing a few features we’ve come to expect from higher-end robots, such as hot-water washing and hot-air drying. But overall, the auto-wash dock was a pro for the price and is a significant upgrade from previous iRobot self-washing docks, which have not been highly rated.
Lifting Mop Pads
The Plus 405 Combo has lifting mop pads, which means whenever the robot senses carpets, it automatically lifts the mop pads to keep them dry. This allows you to vacuum and mop houses with a mixture of hard floors and carpets in the same run, which is much more efficient.
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LiDAR Navigation
All the new Roombas in this lineup use LiDAR, which is a much more accurate way for robot vacuums to map and navigate around the house than VSLAM. The 405 did pretty well with navigation in the various evaluations we conducted.
In our navigation-efficiency evaluation, the 405 set a new Roomba record—covering 0.76 m² per minute, above average for the brand—but still ranks only 30th overall, versus the MOVA P10 Pro Ultra’s 0.82 m² per minute.
Cons of the Roomba Plus 405 Combo
Unfortunately, there were several potential drawbacks to this robot vacuum that are worth noting. Let’s get into it.
Power Metrics
Even though the Plus 405 was good at picking up debris on the surfaces of floors, it didn’t do so well with some other performance metrics. For example, its suction power and airflow were below average on max power.
| Roomba Plus 405 Combo | MOVA P10 Pro Ultra | Average | |
| Suction – Max Power | 0.13 kPa | 1.08 kPa | 0.83 kPa |
| Airflow – Max Power | 10 cfm | 20 cfm | 16 cfm |
That isn’t new for Roombas, as they have always been low-powered compared to other robot vacuums. However, it hasn’t really affected other performance scores until now.
With the more practical performance evaluations, like the deep carpet cleaning, where we see how good it is at picking up deeply embedded debris—the Roomba 405 picked up only 58% of the debris, which was significantly below the average 75%, the MOVA P10’s 81%, and the iRobot Roomba Combo 10 MAX’s 85%. It’s notably the worst score we’ve ever seen from a Roomba with this evaluation.
Whatever the reason, it’s probably the same reason it performed poorly in the 2½-inch flattened pet hair pickup evaluation. It got the lowest score we’ve seen yet, picking up only about half the hair on the carpet. The MOVA picked up the average amount – 66%.
Mopping Ability
One of the worst scores the Roomba Plus 405 Combo received was, ironically, where it did the best. This is related to how the robot vacuum mop combo uses two spinning mop pads electronically fed with water to saturate them. Unfortunately, the 405 doesn’t have multiple water settings—just one water level, which will be important later.
We were surprised to see a record score during our dried-on stain mopping evaluation – where the iRobot Roomba Plus 405 Combo’s score was 145. This is notably far above the MOVA P10’s 73 and the average score of 93.
However, this isn’t the whole story with mop evaluations. If a robot vacuum dispenses too much water, it can score very well on this assessment, but it leaves too much water on your floors, which leaves them dirty. Therefore, the robot vacuum is not a good mop at all. This was indeed the case with the Plus 405 Combo. It left behind a massive amount of water – 5.20g approximately 5x the MOVA and the average robot vacuum we have evaluated.
Obstacle Avoidance
Another drawback is the lack of obstacle avoidance sensors. These front-mounted cameras or lasers help the robot vacuum recognize and avoid household objects.
However, this critique is a little unfair because obstacle avoidance sensors have only recently started appearing in this price range.
Even so, now that obstacle avoidance is available on robot vacuums (e.g., the MOVA P10 Ultra), the 405 not having it is a significant barrier to recommending the product.
Roomba vs. Roborock?
Curious how Roomba compares to Roborock? Use our Robot Vacuum Comparison Tool to explore detailed specs and features—just select the Roborock and Roomba models you want to compare side by side.
The App
In some ways, the app is an upgrade from previous iRobot apps, as this new one seems to have been redesigned completely. And we applaud them for the effort since their previous app was very outdated.
This new app shows promise: it at least has real-time monitoring of the robot vacuum and more granular control over its features than before. But it still doesn’t match options from its main competitors, and the app was consistently buggy in our evaluations—something we’ve heard others mention as well.
Roomba Plus 405 Combo Review: Conclusion and Recommendation
If there’s a silver lining with this new release from iRobot, it’s that their other models (the 105, 205, and 505) all seem like completely different products. There’s a very good chance those are excellent, and we will be updating our iRobot Roomba Buyers Guide with those as we complete our reviews. But the one we evaluated first (the 405) is a letdown.
We are evaluating all the others in Roomba’s lineup and will publish those robot vacuum reviews soon. As for the 405, its current ranking is 70, with a Vacuum Wars star rating of 1.66, where the average is 2.8.
So it’s a pretty big failure. If you want to check out some products that aren’t failures, visit the Vacuum Wars Top 20 Robot Vacuums list, which is updated weekly as we assess new products.
Roomba Plus 405 Combo
iRobot Roomba Robot Vacuum Buyers Guide 2026
iRobot has rolled out a revamped Roomba lineup for 2025, introducing key changes to its long-running series. From the entry-level 105 series to the top-of-the-line 705 series, these new models showcase a range of noteworthy updates that could signal a pivotal shift for the company. This guide delves into their major enhancements and offers insights into how they’ll perform in everyday life. See the Guide
