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Will Robot Vacuums Fall Down Stairs?

Robot vacuums are convenient little devices. Power it on, and the disc-shaped device automatically starts vacuuming your floors, be it carpeted or hardwood. One advantage of this is that you don’t have to stay in the room with it (or even in the house for that matter). While robot vacuums are great, they’re not the best at navigating stairs, which, as we’ve explained before, is one reason why they can’t replace a traditional vacuum. If you’re wondering if it’s OK for you to operate your robot vacuum around stairs, then you’re in luck:

Robot vacuums typically don’t fall down stairs because they’re designed to use downard facing sensors to detect and avoid stairs. If you’re worried about your robot vacuum falling down the stairs, you can use a virtual wall to block it’s path, or add a physical barrier to prevent it from approaching the stair edge.

To put it simply, robot vacuums usually don’t fall down the stairs for a simple reason: the designers add sensors and programming to avoid this problem specifically. And as robot vacuums become more and more advanced, they tend to get better at navigating their environment, especially around risky areas like ledges or stairs. Either way, it’s worth your time to learn about how they work, and as an added bonus, we’ll explore whether it’s possible for you to force it down the stairs so that you can get some cleaning on those surfaces too.

How Robot Vacuums Sense and Avoid Stairs

Robot vacuums come equipped with handy cliff sensors that prevent the automated vacuum from going near ledges and stairs. They do this by transmitting data to the small microprocessor inside the device, which uses the information to alter its cleaning path. Four small infrared sensors on the front and underneath the vacuum prevent the device from bumping into objects as its crossing the floor. What’s more, if it thinks there may be stairs, the vacuum will stop and “think” about it–process it’s sensor data–to be doubly sure it’s not about to take a tumble down stairs.

Most robotic vacuums, like the Roomba 980 (from Amazon), also come with a protective front bumper, and maybe even a more extensive sensor suite than the competition. But all robot vacuums will come with several cliff sensors which are on the bottom of the device and pointed downwards. When the device is powered on, the sensors continuously transmit data to the processor, and this data includes how close the device is to the floor. When the sensors detect a gap between the vacuum and the floor, it automatically replots its path. This is one of the reasons a robot vacuum doesn’t move too fast: so it has time to detect cliffs before barreling over them

What is a Robot Vacuum’s Cleaning Path?

The sensors are responsible for plotting the small vacuum’s cleaning path. It usually starts with the device moving in a spiral path away from the docking station. From there, the robot vacuum moves in a straight line until it bumps into an object and it will then sweep around the edges of the object and continue on its path. It will repeat this process until it is back to the starting point or the batteries need a recharge. As they work, more advanced models may even build a map of the room, though “dumber” models simply operate for an excess amount of time to guarantee the room has been covered. All strategies include programming for handling stairs and avoid damage from falls.

Are Cliff Sensors Reliable?

Cliff sensors are reliable but they do require occasional cleaning for a simple reason: the sensors are close to the ground and will collect dust over time. This is problematic because when the sensors are dirty, they have problems transmitting and receiving data to and from the microprocessor. Thankfully, cleaning the sensors is a breeze; just gently wipe them off with a clean cloth.

How often the cliff sensors need dusting depends on a few factors that include frequency of use and the condition of your floors. The color of your floor or carpeting can also affect the sensors’ reliability. For example, dark and grey colors can confuse the cliff sensors. The darker colors can make the sensors believe the automatic vacuum is near the stairs resulting in a charge of course. That said, the manufacturer will have tested the robot vacuum on dozens of floor types during development.

How this affects its functioning is that some sections of your floor may not be vacuumed if it’s dark in color. What you don’t want to do is cover the sensors to force a robot vacuum to continue cleaning dark flooring. It will prevent the vacuum from stopping, and this is a problem if your home has stairs. If the sensors are not transmitting data, your small cleaning device will fall down the steps. If you cover these sensors, or if they’re covered with dust, more expensive and clever models will stop working and send you an alert indicating the sensors are blocked.

Forcing a Robot Vacuum to Avoid Stairs

Robotic vacuum cleaner going over stairs

There is a way you can force your robot vacuum to avoid stairs without blocking the sensors. You can spend a little extra money and purchase a stationary device called the Virtual Wall, like this one from Amazon. The free-standing device creates an invisible 10-foot barrier the automated vacuum won’t cross. Placing the Virtual Wall near the stairs will keep the vacuum from going down them.

Not everyone wants to purchase another device and there is a cost-free way to keep the vacuum away from stairs. The front sensors and bumper automatically turn the vacuum away when it bumps into an object. This means you can place a stack of books or other non-breakable objects by the stairs. When the vacuum bumps into the object, it will automatically turn away. So, you do have a couple of options, both high tech and low tech, to force the robot to avoid the stairs if you’re worried.

Managing Robot Vacuums in Houses with Stairs

Living in a two-story home doesn’t mean that it’s impossible to manage a robot vacuum around stairs. Along with using a Virtual Wall or stationary objects to block its path, there are other options to protect it. You can always physically move the robot vacuum up and down the stairs. The vacuum is small, and lightweight, so you won’t have any problems carrying it. You can do this without buying anything extra, but that may mean taking a few trips up and down the stairs to empty the device when full, and to recharge it. If you’re not running the vacuums a lot, this may be no big deal for you.

If you upgrade to two docking stations, one upstairs and one on the lower level, your vacuum will always be charged and ready for use. It also means you don’t have to carry it to the original starting place. The other option is purchasing a second robot vacuum which is the most convenient and expensive option, however, with two automated vacuums, both levels of your house will be a breeze to clean; just remember to block off the stairs on the upper floor if you have any concerns about the upstairs robot falling!

Is a Robot Vacuum Right for your Home?

When you’re looking at robot vacuums and trying to decide if it will make cleaning your floors easier, think about the rooms in your home. It doesn’t matter if you have stairs, there are several ways you can keep the vacuum from falling. These vacuums are designed to avoid bumping into objects, but if your rooms are cluttered there will be problems. Hair tyes, wires, and other small objects can get wound up in the vacuums internals if you don’t do a little pre-cleaning ahead of time.

Instead of vacuuming, the device will spend most of its time avoiding the items in its way. Not only does this reduce battery life, but the vacuum also isn’t picking up dirt and debris. Sometimes it’s impossible to pick everything up off of the floor. In this case, you’ll want to look at higher-priced models because they come with powerful sensors that instruct the device to keep vacuuming around the objects.


Robot vacuums are designed to not fall down stairs but there are exceptions to the rule, including when the cliff sensors get dirty, which makes it so there is trouble sending and receiving information from the microprocessor. The color of your flooring also makes a difference. Some sensors have problems telling the difference between the flooring and stairs.

Even with light-colored flooring and clean sensors, you may still worry about the small vacuum falling down the stairs. You can always observe it to convince yourself it can manage the stairs safely, or you can address the problem directly by getting a Virtual Wall device or create one with solid objects in your home. The best advice is to watch the vacuum on upper levels to ensure your robot vacuum isn’t broken or damaged, at least the first few times you use it, until you’re sure you can trust the device to not fall down the stairs.