iRobot Roomba Combo J9 Plus review

The iRobot Roomba Combo J9 Plus is an excellent mopping and vacuuming robot. It's just a little pricey.

Feb 11, 2024 - 10:30
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iRobot Roomba Combo J9 Plus review

One-Minute Review

iRobot’s Roomba Combo J9 Plus (stylized as Roomba Combo j9+) is almost everything you could want from an autonomous cleaning companion, and one of the best robot vacuums if your budget allows for it.

It takes everything that made the Roomba Combo J7 Plus great (we awarded that model four-and-a-half stars in our review) – such as the first of its kind retractable mop pad that folds down from the top of the robot, ensuring zero risk of it wetting your carpet, unlike bottom-mounted mops – and elevates it with improved object detection, more powerful suction, and a smart scrubbing mop (a feature that's since been added to the J7 models).

The upshot is that this sleek cleaning machine will clear pretty much all the dirt you throw at it, with iRobot saying the vacuum delivers “100% more suction power” than its previous models. At the same time, the Combo J9 Plus avoids pet waste and any objects you’ve left lying around that might cause it issues. 

During my months of using the Combo J9 Plus, it has become stuck only once (on its first-ever clean), and a quick edit of the app’s map to label that area a Keep Out zone has meant in the dozens of cleans since it has managed to vacuum and mop my home and return to its self-emptying charging dock with zero issue.

Speaking of which, the Roomba Combo J9 Plus’ base is surprisingly stylish for a bin. A wood-effect top makes it look like (and it could be used as) a small table, meaning it would be fine to have it hiding in plain sight in your living room. That said, the noise of the vacuum emptying is a little loud, plus the base needs to be near an electrical outlet, and have a decent amount of space around.

The Roomba Combo J9 Plus Base in front of a sofa

The Roomba in its base (Image credit: Future)

The only slight disappointment for a robot vacuum at this top-tier level is that the base doesn’t clean its own mop pad. The upside is the base doesn’t store any dirty water, which can become smelly if it isn't changed regularly; and changing the mop yourself is hardly a hassle.

So, the only thing really holding back the Combo J9 Plus Roomba is its $1,399.99 / £1,249 price. As such, those on a budget would do well to keep their eyes peeled at sale time. 

Roomba Combo J9 Plus: Price and availability

  • List price: $1,399.99 / £1,249

The iRobot Roomba Combo J9 Plus is available to buy online, and you can pick it up from either the official iRobot store or Amazon for $1,399.99 / £1,249. The good news for those on a budget is that we have seen it discounted during Black Friday and the January sales, for example, so be on the lookout for a deal.

For the price, you get a vacuuming and mopping robot, a self-emptying base that can refill the robot’s water, too, two mop heads, two AllergenLock bags, a spare filter, and an extra side brush for the first time you need to replace them.

If you want the self-emptying base but no mop then you can buy the Roomba J9 Plus for $899.99 / £949; or, the regular Roomba J9 with no self-emptying base or mop will cost you £699 (only available in the UK).

My advice is to get one of the Plus models with a base. Not having to remember to empty the Roomba every time is a major convenience. The Combo’s mop is certainly handy, too; but no matter what type of home you have, the base is worth the extra expense. 

Whichever model you choose, be aware that there are ongoing costs with this robot vacuum. The self-emptying base station’s vacuum bags need to be replaced when they’re full; the rollers, brush and filter will need to be switched out every so often – the app will notify you when it's time – and if you want the mop to deliver a better clean then you’ll want to use iRobot’s approved cleaning solution instead of regular water.

Value: 4/5

The Roomba Combo J9 Plus cleaning a hard floor

(Image credit: Future)

Roomba Combo J9 Plus: Design

  • Stylish self-emptying and self-charging dock
  • Mop pad that won’t drag on carpet
  • 3.4-inch / 8.7cm tall

The iRobot Roomba Combo J9 Plus shares a lot of design features with its sibling, the Combo J7 Plus, with the best of these being mop placement.

Unlike most robot vacs that raise the mop down from underneath the base, bringing a risk that the mop will brush against your rug when your robot passes onto the raised surface, the Combo J9 Plus’ mop folds down from the top of the vacuum. As such, there's zero chance it will catch on surfaces it shouldn't mop.

The only downside is that the vacuum isn’t able to clean or replace its own mop as some other robot mops. I didn't find this a major inconvenience, though. 

The Roomba Combo J9 Plus mop revealed while it's in its charging base

The Roomba Combo J9 Plus mop (Image credit: Future)

Just like previous Roombas, the Combo J9 Plus is clad in an all-black plastic casing, with a gunmetal disc sitting at the center of the matte surface on the top side. Offset towards the front of the Roomba you’ll find the singular control – a button that can pause or start the robot when you press it mid-clean, or send it home on holding it down for a few seconds.

On the front side of the Roomba you’ll find its camera, and a protective plastic bumper that has some give so that both the robot and whatever it (gently) bumps don’t become damaged. Underneath you’ll find the brush that flicks dirt into the path of the vacuum rollers, as well as two bidirectional wheels and a swivel wheel that allow it to move in all directions.

At the back, you’ll find the robot’s dust bin and water container. The robot automatically empties its dirt and refills its water at the end of each clean  – or mid-clean, if necessary – so you’ll probably never need to deal with it. That is, except to change the filter when the app notifies you to do so.

Size-wise, the Room Combo J9 Plus measures 3.4-inch / 8.7cm tall, and 13.3 x 13.3 inches / 33.8 x 33.9cm in length and width. So before picking this robot up you might want to measure your furniture to see if the Roomba can get beneath it and navigate around it.

The Roomba Combo J9 Plus base with its door open, in front of a sofa

The Roomba base when it's open (Image credit: Future)

The base station is also a fairly sizeable 15.9 x 16.1 x 12.2 inches / 40.5 x 41 x 31cm (h x w x l), and iRobot recommends you have 1.5ft / 0.5m on each side and 4ft / 1.2m in front. It isn't massive, but neither is it the smallest; and it needs to be situated near a power socket, too.

If you do have to place the base in plain sight in your living room, for example, then you’ll appreciate its stylish design and wooden-effect top; it really doesn't look like a bin at all. Do note that the robot vacuum is quite loud when it empties itself, although the sound is no louder than a regular vacuum cleaner and the process is pretty speedy.

Opening up the base reveals the large water storage tank. Those who mop frequently, and have a lot of hard floors, should expect it to last a month. I have fewer hard floors, so that one tank should last a few months. There's also a drawer containing the AllergenLock bag into which dirt is deposited. This will usually require emptying around every 60 days of cleaning – the LED on the front of the base will light up red when it needs emptying. There are also two shelves on the back of the door for storing spare Roomba parts such as the extra dirtbag, filter and brush head that are supplied with the vacuum at purchase.

 Design: 4.5/5 

Roomba Combo J9 Plus: Performance

  • “100% more suction power” than previous Roomba models
  • Smart scrub tackles tougher messes
  • Brush can flick larger debris around a bit before it’s vacuumed

The Roomba Combo J9 Plus is a cleaning powerhouse that’s able to suck up dirt and debris across a range of floor types. 

iRobot hasn’t said how powerful its J9-series models are specifically, but does state that they have “100% more suction power” than its i-Series robots. Previously iRobot said the Roomba Combo J7 Plus came with merely “standard” cleaning power, so we’ve taken this to mean the J9 models are twice as powerful as that robo vac too. 

In our tests, this boost in power saw the Roomba pick up all dirt and debris in its path. The only issue we found was that the brush can flick larger bits around, which can extend the time the robot vacuum spends cleaning. In addition, depending on the shape of your room and furniture placement, it won’t be able to get into every nook and cranny (although it does a pretty great job overall).

In addition to more powerful suction, the Roomba Combo J9 Plus and its J9 siblings arrive with Dirt Detective – some smart software that allows the robot vacuum to learn the areas of your home that get the dirtiest. With this information the vacuum will then turn on its high suction settings or scrub the floors a little harder in those areas.

Speaking of scrubbing, the Combo J9 models with a mop offer a smart scrub feature – that was also added to the Combo J7 models. Rather than simply dragging its mop over your hard floors, when the J9 Combo Plus cleaner detects a tougher stain, it will move back and forth over the area to scrub it clean. 

The Roomba Combo J9 Plus smart scrubbing the bathroom

How smart scrub works on the Roomba Combo J9 Plus (Image credit: iRobot)

Those who want their robot to always deliver the most intense clean can even program the Roomba through the app to use its most powerful suction every time and / or do two passes of every room. Just note that this may mean the robo vac needs to recharge mid-clean, though.

You might also want to invest in some iRobot-approved cleaning solution if you want the mop to give your hard floors a deeper clean.

I'll add that this robot is also very reliable from the perspective that it’s able to clean with (almost) zero human assistance. In my months of testing the Roomba Combo J9 Plus, it has become stuck precisely once – it entered a small gap to go under a unit from which it then couldn’t escape. However, by adding a Keep Out zone in the app (more on that down below) it has never become stuck there again. The only other thing I had to do was remember to open the doors before sending it on a clean, and make sure my lights were turned on the light was low, since the Roomba can’t clean in the dark.

Performance: 5/5

Roomba Combo J9 Plus: App

  • Can program, schedule, and start cleans from anywhere
  • Analyze obstacles and adjust your map as necessary
  • Keep an eye on your vacuum’s health

The iRobot app is your one-stop shop for managing everything related to your Roomba Combo J9 Plus vacuum, and it’s super easy to use. 

Setting up your vacuum is simple via the app, which takes you through the process step by step covering everything from connecting your robot, naming it, and creating your first map. 

The iRobot app showing the robot vacuum's health, its cleaning stats and the main page

(Image credit: Future)

Once your map is complete, you’ll want to do a clean or two – and my advice is to make sure you’re at home while these initial cleans take place. The robot is pretty darn smart and able to avoid obstacles, but as I mentioned above, my cleaner did become stuck on the first clean. Once I'd rescued it, the Roomba completed its task, and adding the area to the Keep Out zone via the app has meant that this hasn't happened again.

Note that this robo vac can snap pics of obstacles it comes across, which you can either mark as another Keep Out zone, as a temporary obstacle that you can make sure isn’t in the way next time, or as an imaginary obstacle that the vacuum doesn’t need to worry about. After those first two test cleans, I’ve been happy to let the Roomba Combo J9 Plus clean while I’m out – and it has always does a great job.

You can also add No Mop and Clean Zones if you want the Roomba to only vacuum a hard surface in that area, and if you want the robot to take extra care cleaning that space respectively.

Lastly in the app, scroll down to the Product Health menu and you can inspect every detail of your robot vacuum’s components. Based on the number of cleaning hours your Roomba has performed, the iRobot app will estimate how long your components have left before they need to be replaced. This is super handy for keeping your Roomba in tip-top shape.

App: 5/5 

Roomba Combo J9 Plus: Battery

  • Cleverly recharges itself when needed
  • Charge remaining only viewable in the app

In all honesty, the battery is a bit of a mystery to me since this robot vacuum handles charging itself. 

Most of the time, the Roomba Combo J9 Plus cleaned my spaces without needing to recharge its battery mid-clean. However, the one time I had it clean every room twice on Max suction settings, it did need to return to base to top up the battery. Nevertheless, it did so without any intervention from me. 

The Roomba Combo J9 Plus emptying its dirt and refilling its water at its base

How the Roomba Combo J9 Plus empties and refills itself (Image credit: iRobot)

Roomba Combo J9 Plus: Score card

Should I buy the Roomba Combo J9 Plus?

Buy it if… 

Don’t buy it if…