Robot vacuums are great, but they can't tackle every cleaning job

A robot vacuum stopped because a cat is in its path
(Image credit: Shutterstock/Sharomka)

Taking the vacuum cleaner for a weekly tour around the home is a chore that many of us would rather avoid. We’d prefer to have someone, or something, do it for us – and increasingly it’s the latter. Robot vacuum cleaners have become increasingly popular in recent years, and having had the opportunity to test dozens of models they’ve certainly revolutionized my house-cleaning routine.

While even the best robot vacuums may not fully replace your upright, canister or stick vacuum cleaner, they can take care of vacuuming an entire floor level in one go. If you live in a flat then it’s even better news, as with just one floor plan to map out, with no stairs or split-levels, a robot vac may be able to take care of the entire clean.

Leading brands are constantly expanding their offerings and adding new smart features, and we’re spoiled for choice by the likes of Eufy, AEG, Roboroc and Shark. However, before you spend a sizable chunk of cash on a robot helper, it’s worth knowing what these things can’t hoover up, as well as what they can.

Read on to discover what dirt and spills we advise you not to let your robot vacuum loose on, and when you’re ready to buy you’ll find the best robot vacuum deals where you are below.

When I first realized robot vacuums have their limitations

As someone whose job involves testing appliances I’ve welcomed a few robot vacuum cleaners into our home, and initially I assumed that they could do it all. But I was wrong – there are some spills which are best for it to avoid.

When I’m testing a robot vacuum, one of the first things I’ll do is scatter some flour on the kitchen floor. “Why would you do that?”, you might well ask.

Well, for one thing I’m quite clumsy, and having a toddler around the house does mean that occasional little accidents are pretty much inevitable. I also like to bake when I get a spare half-hour or so, so for me, scattering flour around a tiled kitchen floor seems like a reasonable test of any vacuum’s capabilities.

a robot vacuum in front of a sofa

A robot vacuum will let you put your feet up, but they're not without their limitations (Image credit: CreativePhotography / Adobe Stock)

Unfortunately, it was a test which the first robot vacuum tested failed miserably. Not only did it skid around on the flour like Bambi on ice, it also somehow got itself covered in the stuff. While it was interesting to study the vacuum’s thought processes as it attempted to maneuver through and around the spillage, I was surprised at the extent to which it was bamboozled by even a light dusting. The brushbar and dustbox also didn’t cope well – they became clogged with flour, and it took some considerable time and effort to clean them.

You may, of course, have had better luck with your robot vacuum sucking up flour, but in the future I’ll be tackling such spills with a good old-fashioned dustpan and brush, or, if I’m feeling lazy, with our upright cleaner.

What else should a robot vacuum avoid?

While most robot vacuums feature obstacle-avoidance technology that enables them to maneuver around larger objects, they’re going to attempt to pick up any smaller objects that are in their path. Hair, coins, Lego bricks, bits of food –  a robot vac will attempt to tackle all of these and more, with varying degrees of success.

Hair – long and short, human and pet – will probably get caught around the brushbar, so unless your robot vacuum has anti-hair-wrap features, that’ll need to be detangled. And even if you can’t necessarily see something on the floor, a robot vacuum will find it – they’re clever like that – and suck it up.

It’s always a good idea to check that the coast is clear of earrings, small pieces of bric-a-brac and the like before your robot vac sets off on a clean

Anything larger than ‘regular’ dust and dirt is likely to be a problem for any robot vacuum. If it isn’t able to detect and avoid an object then that item is going to either get caught up in the brushbar, which could damage said object and/or the brushbar, or be sucked into the dustbox. It’s always a good idea to check that the coast is clear of earrings, small pieces of bric-a-brac and the like before your robot vac sets off on a clean, to ensure that you don’t lose anything of value.

Dried cereals generally won’t be an issue, but when it comes to anything runny or sticky such as banana, soft cheeses and yogurts, most robot vacuums will meet their match. Things can get very messy very quickly, so make sure that such spills aren’t in the path of your robot vac if you don’t want to be regularly cleaning it – trust me on this one.

Send for robomop

If your home is prone to liquid or glutinous spills and you still want an automated cleaner (and I don’t blame you), then it’s worth looking at a hybrid robot vacuum and mop. We’re seeing more and more of these come on the market, such as the Roborock S7 Max Ultra, which collects fine dust and larger debris, while also offering the ability to mop hard floors. Hybrid robot vacuums like this may even take care of emptying the dustbox and dirty water, then refilling the water container. Choose a really good one and your robot cleaner will clean itself, too – how good does that sound?

The Eufy RoboVac X8 vacuuming up oats from a wooden floor

Most robot vacuums will struggle with anything larger than regular dust and dirt (Image credit: TechRadar)

As with most appliances, the more functionality a hybrid cleaner offers, the higher the price tag, and you’ll need to spend around $1,000 / £800 on an all-singing, -all-dancing hybrid – but if you want to remove ‘mopping’ from your chore list then it’ll pay off in the long run (if your budget doesn’t stretch that far, check out our pick of the best cheap robot vacuum deals). As with all robot vacuums, the floorplan mapping can be hit-or-miss, so having a level ground surface with clearly demarcated transitions between different floor surfaces would make things easier for a hybrid robot model.

Checking the route that any robot vacuum will take around your home is advisable, too. It’s always better to be safe than sorry with precious small items, and I’m sure no one wants to spend an age cleaning hairs from a vacuum’s brush bar or sifting through the dust canister looking for that missing earring – after all, that rather defeats the point of having a robot helper that does the messy jobs for you.

Jennifer Oksien
Homes Editor

 Jennifer Oksien is TechRadar’s Homes Editor. Jennifer (Jenny) has over a decade of experience as a digital product writer specialising in appliances, smart tech and mattresses for some of the UKs leading retailers and magazine titles such as Real Homes, Ideal Home and Livingetc. Generally, you’ll find her watching the latest Netflix series, digging around in the garden or attempting to make a cake that is edible.