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iRobot Roomba Combo j9+ Review – the King of Clean?

Welcome to Vacuum Wars and to our review of the iRobot Roomba Combo j9+. It’s iRobot’s new top-of-the-line robot vacuum mop combo with a brand new Clean Base design and a lot of upgraded specs and features. 

Great Vacuuming. Great Mopping.

Product Name: iRobot Roomba Combo j9+



If you’re looking for the cleanest possible floors, the Roomba Combo j9+ should be on your short list. It did very well in our vacuuming and mopping tests and has the features you’d expect in a 2-in-1 robot vacuum in this price range.


  • Vacuuming
  • Mopping
  • App Features
  • Clean Base Auto-Fill Dock


  • Lacks Mop Pad Washing
  • Premium Price

We bought one and put it through all kinds of tests over the past few weeks, and in this review, we’ll go over all the pros and cons of this 2-in-1 robotic vacuum and mop. 



Let us start off with what we consider the main thing, which is the robot’s vacuuming ability. The Roomba Combo j9+ uses iRobot’s dual brush design in combination with a single side brush to vacuum both hard floors and carpets. This is the same brush design used by most Roombas and it has proven to be a good one.

Unboxing our iRobot Roomba Combo j9 Plus
Unboxing revealed there really isn’t any assembly to speak of with the Combo j9+. © Vacuum Wars

In the various pickup tests we did, we found the Combo j9+ to be as good or better than any robot vacuum on the market. It did great sweeping up fine to extra-large debris off the surfaces of hard floors and carpets. 

With dried-on stains, it performed extremely well. Even in our mopping torture tests with dried-on grape juice, it was very impressive.

But the interesting thing here is the Roomba’s newly upgraded power. iRobot says that the j9+ has 100% more suction than the Roomba I-series, and we were able to confirm that in our suction and airflow tests. This extra power really seemed to make a practical difference with its real-world vacuuming ability. 

Carpet and Hard Floor Pickup Tests - iRobot Roomba Combo j9 Plus
The Combo j9+ did great on carpet and hard flooring with all sizes of debris. © Vacuum Wars

For example, with our carpet deep clean test, where we see how good it is at picking up deeply embedded sand, it scored the second-best score we’ve ever seen. It was also better than the i-Series and the previous j-Series Roombas with things like the crevice pickup test. 

In the new promotional material, iRobot claims that the j9 is the “number one cleaning system” based on certain IEC dust pickup tests for both hard floors and carpet, and after testing the j9+ all week, we believe it.

In the box

  • Roomba Combo j9 Robot Vacuum & Mop
  • Clean Base Automatic Dirt Disposal
  • Extra Filter
  • Extra Side Brush
  • Mopping Pad
  • Extra Dirt Disposal Bag
  • Power cord
  • Manual and warranty

Mopping System

We were almost equally impressed with its new mopping system. The Roomba Combo j9+ has iRobot’s Auto-Retract Mopping System. When the robot is vacuuming hard floors, it can lower its mop pad with its two stainless steel arms and vacuum and mop floors at the exact same time

Testing Mopping System in Rooms with Carpet and Hrd Flooring - iRobot Roomba Combo j9 Plus
The Roomba Combo j9+ can vacuum and mop in a single cleaning run courtesy of iRobot’s Auto-Retract Mopping System. © Vacuum Wars

But when it senses carpets, which it does automatically, it will raise up the mop pad and rest it on the top of the robot, preventing carpets from getting wet. iRobot has coined this capability Dry Rug Intelligence.

iRobot Roomba Combo j9 Plus Mopping Test
The Combo j9+ scored very well in all of our mopping tests. © Vacuum Wars

iRobot has been a vocal critic of competing robot vacuums which have auto-lifting pads saying those robots only lift their pads up a few millimeters and are therefore prone to getting carpets wet. They say their system is the only way to ensure that carpets stay dry. 

RELATED: In our recent Eufy X9 Pro review we noted it had the most mop-lift we’ve seen at 12mm.

And, the j9+’s auto-retract mopping system worked great in our tests. It’s hard to overemphasize what a game changer it is that 2-in-1 robot vacuum cleaner and mop combos can now vacuum and mop the floors in the same run, where it used to take two runs to accomplish the same thing.

Robot Vacuum Resources

Mopping Performance 

One of the main reasons we’re excited about the Roomba Combo j9+ is its mopping ability. In our tests, it did noticeably better than other robot vacuum mop combos in key areas

With dried-on stains, it performed extremely well. Even in our mopping torture tests with dried-on grape juice, it was very impressive. It was especially good with handling wet stains, too. 

Mopping Test - Dried-on Stains - Smart Scrub - iRobot Roomba Combo j9 Plus
Testing the new Smart Scrub mopping feature. © Vacuum Wars

Most of the robots we test, especially those with spinning mop pads, essentially just spread large wet stains around. But the Roomba Combo j9+ seemed to handle this much better. 

It also has a new mopping feature called Smart Scrub. When enabled, it mops in a pattern which is essentially two times as effective. We tried this out with dried-on stains and we were really surprised at how well it did.

Tip: Own a Combo j7+? The new Smart Scrub mopping feature has also been rolled out for that Roomba model, too!

Obstacle Avoidance

Another big pro is its obstacle avoidance system. The Combo i9+ uses front-mounted sensors to detect and avoid common household objects, preventing it from getting stuck or making messes. 

Obstacle Avoidance Testing - Roomba Combo j9 Plus
The Combo j9+ performed well in our obstacle avoidance tests. © Vacuum Wars

This feature is only available on more expensive robot vacuums like this one. In our obstacle avoidance test, the j9+ scored about the same as its main competitors. It wasn’t perfect, but certainly much better than not having obstacle avoidance. 

Clean Base Auto-Fill Dock

One of the best new features, exclusive to the Combo j9+, is the Clean Base Auto-Fill Dock. In addition to charging the robot and automatically emptying its dustbin into a disposable bag, this new dock can also automatically refill the robot’s water tank.

iRobot Roomba Combo j9 Plus purchased for this review
The iRobot Roomba Combo j9+ we purchased for this review on its Clean Base Auto-Fill Dock. © Vacuum Wars

iRobot says its dust bags can hold 60 days’ worth of debris and the water reservoir can hold 30 days of water. We think the new bin design looks cool too, with its faux wood top. It also has extra pads and bags available in its convenient storage compartment.

App Features

The final pro we’ll mention is its app. iRobot has always had easy-to-use apps with a lot of features. It has things you’d regularly use like map storage, scheduling and Keep Out Zones (no-go zones) for directing the robot away from certain areas. 

Recording Suction and Airflow - iRobot Roomba Combo j9 Plus
Measuring and recording suction and airflow. © Vacuum Wars

There’s also the opposite of Keep Out Zones called Clean Zones. With Clean Zones you can note areas on the map that are more prone to being dirty for a more targeted cleaning. iRobot’s examples for potential Clean Zones are a couch or kitchen table. 

There’s also a brand new feature called Dirt Detective, which “learns from past cleaning missions to automatically prioritize dirtier rooms and adjust settings like suction, cleaning passes and scrubbing.” (iRobot

The app also offers power and water level customization options, bin behavior options, and more. It’s also compatible with Alexa, Siri and Google Assistant. Basically anything you would want to find in an App for a robotic vacuum cleaner is there.


Lacks Mop Pad Cleaning

Moving on to the cons, iRobot opted not to have its Roomba’s new docking station design wash the robot’s mop pads automatically. Some competitors have started to do this, and we’re seeing more and more include the feature on premium robots lately. 

Mopping Pad - iRobot Roomba Combo j9 Plus
After mopping, the j9+’s mopping pad needs to be washed manually. © Vacuum Wars

So, with the Combo j9+ you still need to wash its mop pads after each run manually. While auto mop pad washing would have been a nice addition, iRobot noted that adding mop pad washing can cause sanitary problems. 

If you add mop pad washing to an auto-empty bin system, it can create messes where the water and debris mix in the tray. It also means you have a large dirty water reservoir to deal with, which can emit odors. So, one could view the Roomba Combo j9+ as a more sanitary option than its competitors if you’re a glass-half-full kind of person. 

The navigation on the Combo j9+ was good, mapping and vacuuming the house in efficient rows. However, it was slightly less efficient than some competitors, taking about 10 minutes longer on average to clean our test area. We didn’t find this to be a big deal by any means, but are noting it. It took about 25 minutes to make an initial map with its fast mapping system, which is longer than some competitors.


Overall, we were very impressed with the Roomba Combo j9+. Its pickup, extra power, dual brushes, and unique pressurized mopping system make it an easy choice if your primary concern is having the cleanest possible floors. 

And, beyond its cleaning performance it boasts all the advanced features you’d expect from a top-of-the-line robot vacuum, like obstacle avoidance and an auto-empty bin.


Roomba Combo j9+ Specs

FeatureRoomba Combo j9+
TypeRobot Vacuum & Mop
Obstacle AvoidanceYes
Suction2x i-Series
Mop SystemStowable Single Mop Pad
Robot Water TankElectronic
Mop Pad WashingNo
Alexa CompatibleYes
Google Assistant CompatibleYes
Siri ShortcutsYes
BatteryLithium Ion
Robot Dimensions3.4” x 13.7” x 13.7”
Docking Station Dimensions15.8” x 16.4” x 16.3”
Where to BuyAmazon
Specs from the iRobot website and Roomba Combo j9+ manual.

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