The hidden costs of robot vacuums revealed

Whether you have kids, pets, or just want a helping hand around the house, robot vacuums are useful tools for keeping your home clean. If you pay extra for a model with a self-emptying bin, you don’t even have to touch it for days, if not weeks. But there are hidden costs associated with robot vacuums that first-time buyers might not be familiar with.

Not only do you need to empty the bins every so often, you also need to buy replacement parts–especially if, like most owners, you use your robot vacuum every day. If you don’t replace its worn-out parts on a regular basis, your robot vacuum may stop working properly, resulting in less efficient cleanings and dirtier floors.

From dust filters to roller brushes, here’s a list of parts you need to replace, how frequently you need to do so, and approximately how much they cost. 

This feature is part of TechHive’s in-depth coverage of the best robot vacuums.

Note: We’ve included generic shopping links for the various replacement parts to help get you started, but make sure to match any replacement item with your robot vacuum’s make and model number before you buy.

6 robot vacuum parts you’ll need to replace

Side- or edge-sweeping brush

• How often to replace: Every 3 to 6 months or when visibly worn
• Approximate cost: $10 to $16 for a four-pack; certain models use 5-prong corner brushes that can cost up to $22 for a three-pack

The side brush (a.k.a. the “edge-sweeping” brush) on a robot vacuum is designed to sweep away dust and debris from the corners of rooms, the edges of walls, and the bases of furniture and other large obstacles.

These spindly and somewhat delicate little brushes can get pretty worn down over time, and if you use your robot vacuum often enough, they can bend and even break, thus lose their effectiveness.

But if you replace the side brush on a regular basis, it’ll keep performing like a champ (oh, and don’t forget to clean the side brush, too).

Roller brush

• How often to replace: Every 6 to 12 months or when visibly worn
• Approximate cost: $12 to $20 depending on model

Roller brushes are the primary mechanism that robot vacuums use to rustle up and remove dirt and debris from the floor. They’re especially useful for cleaning carpets or rugs, as the rotating bristles of the brush are very effective at combing out pet hair and embedded grime.

Over time, these roller brushes will get gunked up with grime and hair. Even if you do clean them regularly, the brushes do get worn down after extensive use and will be less effective at cleaning. 

So yes–you’re going to have to replace then every once in a while.

Dust filters 

• How often to replace: Every 6 months or every 50 or so rounds of cleaning
• Approximate cost: $2 to $7 depending on model

Much like filters on air purifiers, the filters on a robot vacuum trap dust, dirt, debris and other airborne particles. And just like how you should replace the filters on your air purifiers every so often, you should change the filters on your robot vacuum too.

Clogged filters can restrict airflow, making it harder for the vacuum to pick up dirt and dust. They can also lead to overheating; if a filter is blocked, a vacuum’s motor needs to work harder to compensate. Of course, filthy odors can also lead to unpleasant odors. 

Brush guard 

• How often to replace: Every 3 to 6 months or when the rubber strip on the guard becomes visibly worn
• Approximate cost: Around $8

Found on some robot vacuum models but not others, a brush guard is a rectangular piece of plastic located underneath certain robot vacuums that essentially protects and assists the main brush when cleaning. It also prevents cords from getting tangled up in the main brush enclosure.

If you don’t replace the brush guard on a regular basis, they’ll be less effective at protecting the brushes, making it that much likelier for them to get gunked up and entwined with hair, fur and debris.

Battery

• How often to replace: Every 2 or 3 years
• Approximate cost: Around $15

Robot vacuums are often left alone to work for hours on end, which can certainly do a number on their battery lives over time. As the battery gets worn out, the bot won’t be able to finish a run without having to return to its base. Each run will therefore take longer, and you’ll have to spend more time keeping your home clean.

That said, you likely won’t have to replace the battery too often; only around 2 or 3 years or if it starts to malfunction. 

Disposable dust bags (for self-emptying base stations)

• How often to replace: Every 2 to 3 months
• Approximate cost: $20 for a 3-pack

If you have a self-emptying robot vacuum, it likely came with disposable dust bags. These are definitely designed to be tossed out once they’re full up, which can take 2 to 3 months depending on how often you use your robot vacuum.

If a dust bag gets too full, it could impact the robot’s ability to automatically empty its bin; either it won’t do it at all or it won’t be able to start a run if it happens. 

Mop pads (for vacuum/mop combos)

• How often to replace: Every 3 to 6 months
• Approximate cost: $20 for a 3-pack

Some robot vacuums are vacuum/mop hybrids, which would require you to replace the mop pads (or mop heads, as pictured above) as well as the brushes.

Mop pads can get very worn down over time, and using a worn-down mop pad will result in a less efficient clean. If your vacuum mop has an auto-wash feature, however, you might be able to get away with going longer in between replacements. 

A word on replacement kits

While we’ve listed the cost of the replacement parts individually, most robot vacuum companies do offer “replenishment kits” that include replacement brushes and filters in an all-in-one package (That goes to show how often you need to replace them!). This can be cheaper than buying the items individually, but the kits themselves are a little on the expensive side.

A Roomba replacement kit with three filters, three edge-sweeping brushes and two roller brushes of a higher-end model is priced at around $62, and you’ll need at least two a year. You can also opt for third-party solutions, but be careful as they can often be of shoddy quality.