Consumer Reports: Beware of robotic vacuum cleaners

Holiday shopping is right around the corner and robotic vacuum cleaners are expected to be on many wish lists. But beware while those smart vacs are good at picking up dirt, they can be bad about navigating themselves.

This spring, Deputy Brian Rogers of the Washington County Sheriff's Office in Oregon responded to a call of a burglar rustling around in the bathroom of a home.

"And it sounded, initially it sounded like the subject in the bathroom was trying to get out the back window," he said.

There was an intruder in the bathroom wiping the dust from the floor.

"It was very clean, it did a very thorough job. It was stuck in there for a while so it appeared to be pretty clean," said Dep. Rogers.

So how do you keep your robotic vacuum from wandering into uncharted territory? Consumer Reports testers have some advice.

"Some robotic vacuums come with magnetic strips that you place along the doorways to keep the robot from crossing. Others come with a device like this that creates a virtual boundary using infrared beams to keep the robot in or out," said Alex Nasrallah.

More and more models come with an app that lets you create boundaries with a swipe of your finger.

CR tested robotic vacuums' ability to pass over rug fringe without getting tangled and found thick bathroom mats should be avoided. And there are some other ways to keep robots from roaming.

"The dock should be butted against the wall, with a couple of feet of open space around it. And if your dock were to move, the robot may have difficulty finding it, and could wander around your house until its battery dies," said Nasrallah.

And even pros can find a glitch by happenstance.

"We had one test model that would be missing from its dock every morning, and I would have to search throughout the lab to try and find it. It turns out that the robot was unintentionally set to go out and clean every morning at 4 o'clock. And all it took were a couple of clicks on the remote. So that's something to watch out for," said Nasrallah.

Consumer Reports said the first time you use a robotic vacuum, watch it as it roams around your house. It's the best way to notice obstacles like cords it might get caught in, or low dining chairs or coffee tables that it might have trouble navigating.