A problem with Cliff

No, not this Cliff.

No, not this Cliff.

Something more like these cliffs:

You see, my Roomba has what are called “Cliff Sensors”.  These are 4 little infrared sensors that point downward at the front edge of the vacuum.  These sensors will stop the Roomba from going over the edge of a staircase, so in theory they are quite vital to the proper functioning of the vacuum.


As I discovered, Roomba’s cliff sensors can not tell the difference between a sheer vertical drop and a black carpet.  My carpet is mostly black.  Oh, the joy of finding this out!

As my carpet had been getting cleaner and cleaner, I would here more and more frequently the sound of the vacuum stopping and the female voice saying “Error: six”.  At first I had thought it was saying “Error: fix” and what I would do was pick it up, clean out the bins and brushes and send it on its merry way again.

Sometimes this error message was followed by instructions to clean Roomba’s cliff sensors.  That’s when I realized it was saying “six” and not “fix”.  I looked up error six in the manual and got concerned because those fucking cliff sensors were clean as clean could be.  I was starting to worry that something was wrong with my expensive new vacuum.

It got so bad that when the carpet was totally clean, the Roomba wouldn’t work for more than a few seconds before it announced that it was shutting itself down for fear of falling off the edge of the world.

Oh noes!

After emailing iRobot with my concerns, I tried the Roomba on a different carpet and made a guess.  Turns out my guess was right.

As a Google search verified, the cliff sensors roll over and die when faced with a black carpet.  They are no match for it.  Solution?  Packing tape.  Just enough to keep those infrared sensors refracting in on themselves and fooling Roomba into believing that there is terra firma all about.

This, I suppose, makes the Roomba blind to cliffs, and now I will have to use the provided “virtual walls” and other obstacles to keep it from going down stairs.  All just the same.  After I applied the specially folded and cut tape, it runs like a champ.  I can now use it as I have read that it is supposed to be used:

  1. push “CLEAN” button
  2. watch it freak-out house pets
  3. watch it sail back into the “Dock” to recharge after a full session of cleaning

And I guess all is well, and I do say I’m impressed and made glad by my new robot.  If I run it every morning, I should never have to break out the old vacuum again for the carpet.