... I've also had to take apart the gear boxes a few times, and clean them out. It seems like I'm constantly fixing them now. 2 of my units were refurbs, while 1 was bought brand new. The one I bought brand-new has required the most work to keep running, but it's also the oldest. it goes to show that buying refurbed is a good idea. I like my Roombas, but I really wish they had a better design for the bumper sensors.
I've never had my bump sensor fail, but i have to spend 10 minutes pulling (long) hair out of the rotating parts every week. It's definitely not a simple empty the bin / clean the brush maintenance every week. Recently I had to disassemble parts with a screwdriver to find out why it would stop running after a minute or so. Some plastic gears were jammed.
I just looked at their website, and this comment under the Series 500 cleaning module fits my problem exactly:
I want to personally thank the person that wrote the review of buying the 700 module instead of this one. I had given up on this roomba for the same reasons people were reporting (i.e. pet and human hair would gunk up the gears and get them stuck). With this module I would spend more time cleaning the stupid brushes than the time it spent cleaning. Not very efficient.
I decided to give the 700 module and the aero bin a shot and now the thing works like it is supposed to (i.e. vacuuming).
I guess I should try the 700 series module, as well. :thumbsdown: for $50 maintenance item.
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My impression is that you need to spend $50-$100 on parts every 2-3 years to keep these things running. It looks like I need to spend $85 on upgrades to fix their Series 500 design problems. Hopefully I don't have to replace the battery soon...