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iRobot Roomba 870
Robot Vacuum Review

By Derek Hales | Updated August 6, 2018

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The Roomba 870 robot vacuum cleaner provides automatic vacuum cleaning that can be manually started at the touch of a button or scheduled at specific days and times. The 870 was one of the first Roomba’s to include iRobot’s AeroForce cleaning, which improved cleaning by 50% (according to iRobot.com).

Continue reading below to discover if the Roomba 870 is the best robot vacuum cleaner for you.

irobot roomba 870 review

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Detailed Score

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Pros

  • AeroForce improves airflow and cleaning
  • Setup schedule to run at specifics days / times

Cons

  • No smartphone control
  • Model is a few years old

Bottom Line

  • This is a great choice if you want the advanced Roomba 800 / 900 model features, but don’t care about the smartphone / app control.
  • This vacuum is a good value, especially if you can find it in the medium price tier, otherwise a new Roomba 890 is probably a better choice.

Score

%

  • Design 93%
  • Performance 90%
  • Quality 93%
  • Usability 92%
  • Value 89%

Design

Aesthetically, the Roomba 870 robot vacuum cleaner has the typical Roomba circular style. The exterior light gray ring gives way to darker and darker shades transitioning to the black central panel, which surrounds the primary silver control button.

Design Features

  1. Sensor
  2. Handle
  3. Power / Clean
  4. Settings
  5. Filter Release
Roomba 870 robot vacuum features

How It Cleans

Like most Roomba models, the Roomba 870 works by driving around your home, gently bumping into furniture, walls, and other obstacles. Over time, it learns what home looks like, which helps reduce the number of bumps.

Additionally, the 870 Roomba, along with other more advanced Roomba models, is able to sense dirt and other heightened soil levels immediately around it. This allows the Roomba to focus cleaning on areas where it is most needed.

The Roomba 870 was one of the first Roomba models to include iRobot’s AeroForce cleaning system. This new system created an increase of airflow, resulting in improved cleaning and less maintenance. Roomba has maintained and improved its AeroForce system and the third generation is presently included within the Roomba 890, 960, and 980 models.

Cleaning Features

  1. Front Wheel
  2. Spinning Brush
  3. Wheels
  4. Debris Extractors
  5. Dust Bin
Roomba 870 robot vacuum cleaning features

The Roomba 870 is the first robot vacuum cleaner I purchased. My wife and I purchased it shortly after getting married with our wedding gift cards. As of fall 2017, we’ve owned the Roomba 870 for three and a half years.

When we were researching and trying to decide on the best Roomba model for us, the AeroForce technology was a major driving factor. Not to say the other Roomba models are bad at cleaning, but it definitely felt like there was a significant enough performance difference (up to 50% according to Roomba, see tests below for more info) that we were willing to spend the extra money.

Size & Dimensions

The Roomba 870 is approximately 3.6” tall. This allows the Roomba to drive under beds, tables, and other furniture, cleaning areas that otherwise would be ignored or hard to reach.

irobot roomba 870 size and dimensions

iRobot Roomba 870 size and dimensions

This Roomba is built like a tank. It has a decent heaviness at 8.4 pounds and the external bumper ring is quite resilient. The first few times you use your Roomba you’ll want to keep an eye on it, watching for places in your home it might get stuck.

During the first few weeks that we had the 870 Roomba, it attempted to clean under a taller gel-type kitchen mat. The mat was pliable enough that the Roomba was able to wedge itself between the mat and the counter, resulting in a number of deep scratches along the surface. These scratches were purely cosmetic- however, I certainly would have preferred if they did not happen. So keep an eye out for areas where the Roomba might get stuck.

Accessories & Parts

The Roomba 870 vacuum cleaner includes the typical accessories you would expect:

  • Virtual wall barrier x 2
  • Charging station
  • Battery
  • HEPA filter
  • Side brush
irobot roomba 870 accessories

iRobot Roomba 870 accessories

The virtual wall barrier is used to prevent the Roomba robot vacuum cleaner from going into a particular room or space. I have mine setup around my desktop computer, to keep Roomba away from the cords. The Roomba 870 comes with two virtual walls, but if you need extra you can always add as many as you need.

You should note, that you don’t need to place these barriers on most stairs. Most Roombas can see when it’s about to drive off a staircase and will stop itself. However, if you’re worried that it might not identify your stairs or there are other ledges that a Roomba might drive off, you can always use the virtual wall there for extra safety.

Lastly, let’s talk about the cleaning accessories. The Roomba 870 robot vacuum includes three basic components, the rotating brush, HEPA filter, and debris extractor (the rubber spinning tubes on the base). Over time, you’ll need to replace these, as they can get damaged or just wear out. However, they are all quite inexpensive to replace (around $30 for 1-3 years of accessories, depending on how often you vacuum).

If you suffer from allergies you should make a point to replace the HEPA filters more regularly. The rotating brush should be replaced when it becomes flimsy from use or otherwise doesn’t appear to be cleaning properly. If the brush gets caught on something it can quickly wear itself out, so you may want to watch your Roomba the first few times it cleans your home.

I made the mistake of not doing this. My Roomba 870 got stuck in a bathroom rug and wrapped the rotating brush into the rug strings. As a result, the brush had to be replaced immediately. Fortunately, they are quite inexpensive to replace.

Cleaning Tests

The following vacuum cleaning tests are designed to show how the iRobot Roomba 870  performs on a variety of surfaces picking up a variety of debris. For these tests we look at hard floors, low pile carpets, and high pile carpets. For each floor surface type we test the vacuum cleaner against rice, dry cereal, kitty litter, and sugar.

Hardwood Floor

Each of the following substances were spread out across our hardwood flooring testing lane. After spreading out each debris type, we proceeded to complete the vacuum test. This test consisted of forward and backward passes through the various debris types.

To measure the amount of debris picked up by the vacuum, we first measure the dust bin before running the vacuum. Next, we vacuum up the mess and take a new measurement of the dust bin, which in turn gives us the total amount, in ounces, of debris picked up by the vacuum.

Bear in mind, some of the debris may have been picked up but did not make it all the way into the dust bin. For example, there may be pieces of debris stuck in the brushes or hoses leading to the dust bin.

  • Hardwood – Rice 96%
  • Hardwood – Cereal 89%
  • Hardwood – Kitty Litter 98%
  • Hardwood – Sugar 94%

iRobot Roomba 870 robot vacuum cleaner hardwood floor cleaning tests

Low Pile Carpet

The low pile carpet test is virtually identical to the hardwood floor test, except the debris is spread out across low pile carpet. Measurements are recorded in the same way and the same number of passes are made through the debris fields.

  • Low Carpet – Rice 98%
  • Low Carpet – Cereal 18%
  • Low Carpet – Kitty Litter 99%
  • Low Carpet – Sugar 57%

iRobot Roomba 870 robot vacuum cleaner low pile carpet cleaning tests

High Pile Carpet

The high pile carpet test is virtually identical to the hardwood floor and low carpet test, except the debris is spread out across high pile carpet. Measurements are recorded in the same way and the same number of passes are made through the debris fields.

  • High Carpet – Rice 85%
  • High Carpet – Cereal 82%
  • High Carpet – Kitty Litter 82%
  • High Carpet – Sugar 94%

iRobot Roomba 870 robot vacuum cleaner high pile carpet cleaning tests

Usability

Overall, the setup and usability is straightforward and painless. Simply plug in the charging station and place the Roomba 870 on the charging pad. Once it’s on the charging pad, the battery will light up, letting you know the charging pieces have made contact with each other. Or, if you prefer, you can simply press the “Dock” button on the top of the Roomba.

Roomba 870 Battery

With a full charge the Roomba 870 can vacuum for up to 90 minutes

You can run the Roomba manually any time you desire by simply pressing the Clean button (press it twice if the Roomba is asleep). Or you can also setup a weekly schedule for your Roomba to run on. In the case of the schedule, you can set a specific time each day for the Roomba to run on, running it up to once a day each day of the week.

Maneuverability

As with most robot vacuum cleaners the Roomba 870 offers great maneuverability. The robot vacuum cleaner is able to clean in any direction. The 3.6” height profile means it is also small enough that it can clean under beds, dressers, and other furniture.

The circular shape of the Roomba 870 does make it more difficult to clean corners. However, the spinning brush provides a slight extension beyond the circular structure of the Roomba to clean corners.

Roomba 870 cleaning paths

Cleaning paths of the Roomba 870 over a 10 minute period

Maintenance

The following table indicates the frequency at which you will likely want to replace the various maintenance components of the vacuum. The following replacement frequencies are what the manufacturer recommends. However, your individual experiences may vary.

Accessory / PartReplacement FrequencyReplacement Cost
Dust BinEmpty After Each UseCheck Price
HEPA filter2 monthsCheck Price
Spinning brush6 - 12 monthsCheck Price
Front wheel12 monthsCheck Price
Debris extractor12 - 24 monthsCheck Price
Battery24 - 48 monthsCheck Price
Maintenance on the Roomba is fairly simple. The most common maintenance task is simply emptying the bagless dust bin. Depending on how dirty your home gets you will most likely want to empty the bin every 1-2 vacuumings.

The spinning brush is the item you will most likely item you will need to replace to ensure proper functioning. Over time the brushes will get looser, resulting in a decline in cleaning performance. You could simply change them every few months if you prefer. However, I think it’s more prudent to simply replace as needed. Even if you don’t replace them, you’ll want to watch to ensure the spinning brush doesn’t get clogged and stop spinning. Long hair or other tangly debris can prevent the brush from spinning at its full capacity.

If the brush does stop spinning due to hair or other debris, you can remove it with a small screw driver, dislodge the debris, and then screw the brush back into place.

irobot roomba 870 how to spinning brush

How to remove the spinning brush on the Roomba 870

The internal HEPA filter should be cleaned every few vacuumings. iRobot recommends cleaning by simply bumping it against the trash can, which works reasonably well in most cases. In my experience I also dislodged debris with my finger, hot water, and compressed air. Eventually, you will want to replace the filter (especially if you suffer from allergies). As with the spinning brush, it is best to replace if you feel like performance is being negatively impacted.

irobot roomba 870 how to filter

How to remove the filter on the Roomba 870

Next, we have the debris extractors. These are the spinning rubber cylinders on the base of the Roomba. As with the spinning brush, these are most likely to be clogged with long hair or other tangly debris. You should check your Roomba for these types of debris to ensure the debris extractors can still spin. Over time, you may want to replace the debris extractors, however, they seem to have the longest life span of any of the replacement components.

irobot roomba 870 extractors

How to remove the debris extractors on the Roomba 870

In my experience over a 3.5 year period of ownership,  I replaced the spinning brushes approximately 3-4 times, I replaced the HEPA filter about once a year, and I had not yet had to replace the debris extractor (though it’s looking like it needs to be replaced soon).

Lastly, we have the front wheel. Driving around full time can be hard work on the Roomba, so you may want to replace the front caster wheel every 12 months, especially if it appears to be worn down.

iRobot recommends replacing most of these components much more frequently (see table above). While you’re still under warranty that may be a good idea.

Noise

All vacuum cleaner reviews on Modern Castle are put through our standard noise test. For this test, we use a sound meter to measure noise in terms of decibel level.

For this test, we look at how loud the vacuum is at full power while also at about 3′ away from the user. We use this length to symbolize “arm’s reach”, which is generally the distance users interact with and hear vacuums at. While robot vacuums are a little unconventional in their cleaning methods, and the vacuum may be much greater than 3′ away from users,  to be consistent, we will continue to use this distance for all vacuums in the standard noise test.

irobot roomba 870 decibel test

At 3 feet away, the Roomba 870 emits 61 dB of sound.

Battery

The Roomba 870 robot vacuum cleaner comes equipped with iRobot’s XLife Extended Life battery. This battery is 3,000 mAh and lasted 2.5 years.

Regarding its longevity, I would say that 2.5 years is a reasonably good lifespan. During the first year especially my wife and I ran the Roomba 3 times a week. Over time, we ran it less, but still on average once or twice a week.

The Roomba takes anywhere from a few hours to charge up to 16 hours- depending on how low the battery is. If it is completely dead, the time it takes to charge can vary, especially taking into account how long it has been dead for. For regular use a few times a week my Roomba generally took a few hours to re-charge.

With a full charge, the Roomba can vacuum for 1-1.5 hours, depending on the number of obstacles and floor type. The Roomba can usually vacuum areas of around 1,000 square feet without issues. If you have a large house you may need to run the Roomba 2-3 times in order to clean all spaces. Again, the cleaning time varies based on size, number of rooms, room layouts, obstacles, and the level of dirt.

BatteryDetails
Size3,000 mAh
Charging Time2-3 hours
Run Time1-1.5 hours
Run Length1,000 square feet
Replacement CostCheck Price
When my original Roomba battery died, I decided to go with a generic battery instead of replacing with a new Roomba XLife battery. It was about one quarter of the price of the replacement official Roomba battery and also has about 15% more capacity at 3,500 mAh. I’ve been using this battery for about a year and so far it has worked wonderfully.

Regarding replacing the battery, it is unclear if that would void the warranty, but it does seem like it might. Roomba’s warranty states that the following is not covered:

“…use of spare parts or other replacement items (including consumables) which are not provided or recommended by us;”

However, the warranty is only 1 year, so if you’re outside of the 1 year period you could choose to go with a generic battery without as much risk.

irobot roomba 870 how to battery

How to remove the battery on the Roomba 870

Value

Overall, I would say that the Roomba 870 robot vacuum is a solid value for users who prioritize convenience, yet still want a quality clean. This robot vacuum is a pricey unit, as many of them are, but the performance, cleaning power, and general low maintenance make the Roomba 870 a nice value.

While it lacks some of the fancy bells and whistles of newer Roomba models, like Wifi-enabled or smart phone controls, these factors do not impact the quality of clean this vacuum provides, and may not be a deal-breaker for some users.

Specifications

Below is a complete list of important specifications and features included on the iRobot Roomba 870 robot vacuum cleaner.

Specifications 
TypeRobot
ManufactureriRobot
ModelRoomba 870
Length (inches)13.9
Width (inches)13.9
Height (inches)3.6
Weight (pounds)8.4
Floor TypeAll (indoor)
Battery3,000 mAh
CordlessYes
BaglessYes
Returns30 days via Amazon. Varies by retailer
Warranty1-Year limited
PriceCheck Price

Who Should Buy the iRobot Roomba 870 robot vacuum?

The Roomba 870 strikes a nice balance of performance vs. money. It’s not as complex as the Roomba 900 series, but that also means it is less expensive and you don’t have to pay for features that may not matter to you. Cleaning performance is quite solid across the board, maintenance is reasonable, and the convenience of simple scheduling rounds out a great robot vacuum.

I would recommend the Roomba 870 robot vacuum cleaner if you’re looking for the following features in a vacuum:

  • The convenience of a robot vacuum – A robot vacuum offers more convenience than any other type of vacuum. With the Roomba 870 you can simply hit the start button a couple times a week or schedule it and never worry about it again.
  • Minimal maintenance – There is not significant maintenance with the 870 Roomba. You’ll want to periodically clean out the dust bin, in addition to changing / replacing filters and brushes periodically. Beyond that, there is no major maintenance.
  • High performance, high value – The Roomba 870 includes AeroForce cleaning and mapping of your home over time. Both of these features give it a major step up over previous Roomba models. This provides a nice mix of strong performance and excellent value for the money.
  • You don’t need WiFi or app control – The 870 launched prior to Roomba’s expansion into WiFi and app enabled vacuum control. So if you go with the 870 you’ll want to be okay with the fact you cannot control the vacuum from your phone.

For more information on the Roomba 870 see Amazon.com.

Last Updated - August 6, 2018

The following logs all major updates and changes made to this page.

  • August 6, 2018 – Updated the review score as part of our site-wide 1.0 scoring overhaul. Score decreased from 93% to 91%.
Strong Cleaning, Solid Value
  • 93%
    Design - 93%
  • 90%
    Performance - 90%
  • 93%
    Quality - 93%
  • 92%
    Usability - 92%
  • 89%
    Value - 89%
91%

Summary

The Roomba 870 is a few years old, but continues to be a strong robot vacuum cleaner. While it does lack WiFi connectivity, the Roomba 870 is packed with features including scheduling, automatic recharging, AeroForce cleaning (5x air flow), HEPA filter, and more. If you can find the Roomba 870 on sale, it’s a worth checking out, otherwise, you’re probably better off with the Roomba 890.

Derek Hales

Derek Hales

Editor-in-Chief

Derek Hales is the Editor-in-Chief and Founder of ModernCastle.com. He is a passionate perfectionist when it comes to testing and reviewing products for the home. When he is not testing new products, Derek enjoys golf, tennis, and PC gaming. Derek lives in Phoenix, Arizona, with his wife, Samantha, and poodle, Tibbers.