When a robot vacuum like the Roomba from iRobot is working effectively, it’s an incredibly convenient little piece of technology that lets you keep your home clean without even having to think about it. When there’s something going wrong, though, like the Roomba’s red light flashing while it’s charging, it can be frustrating to figure out how to fix it.
The good news is, this is a relatively simple problem to diagnose and fix if you know how to go about it. The iRobot help site isn’t always the best at telling you what you need to do to fix problems, we scoured the web for experts to tell us exactly what to do in this annoying situation.
It depends on what series of Roomba you own. If you have a 500- or 600-series Roomba, check to see if the yellow light is also flashing. If so, the red light isn’t an issue; it just means the Roomba’s battery was very low and is going through a more intensive charging cycle. This cycle will last longer than the usual charge. Leave it be for a few hours; it should be ready to go once the cycle’s finished.
If you have a higher-series Roomba, a Roomba flashing red light is a sign of a problem. The number of times that the battery indicator flashes will tell you exactly where the issue is taking place, which can make it a lot easier to diagnose and fix the problem. iRobot has a chart on its support site that explains this system in detail.
Roombas will also flash red light if the battery is too low when you try to start a cleaning cycle. If it’s doing this while it’s sitting on the charger, it may not be recognizing the charger for some reason. Make sure the Home Base is plugged in and powered and that the Roomba is successfully locking into place on it. If it won’t lock in, double-check the base of the Roomba and its port on the Home Base to make sure there aren’t any obstructions in the way before pursuing repairs.
You may not have paid much attention to the Roomba while it was charging successfully, so when something goes wrong you might not be completely sure what it’s supposed to look like when it’s working right.
There are subtle differences in the design of the Roomba and the Home Base charging station between different models. Make sure you’re looking for the right indications for your model when you’re trying to assess where any problems are coming from.
First, look at the home base. When you first plug it in, the power light should blink green every few seconds. After that, it may keep blinking or it may stop, depending on the model. If you’re not sure that the home base is working, just unplug it and plug it back in, then look for that blinking light. Different models will also display differently while the Roomba is charging. On some, the indicator light will stay illuminated a solid green throughout the charge cycle; on others, it will turn off after a few seconds to save energy.
On 500- and 600-series Roombas, the “Clean” light should pulse yellow during the charging cycle. Like with the home bases, it may pulse for the entire cycle or may turn off after about a minute. These Roombas also have a special heavy-duty charge cycle they go into when they sense the battery has been completely discharged. If it goes into this “refresh” cycle, you’ll see the “Clean” light quickly flashing both red and yellow.
You can interpret the indicators basically the same way on a 700- or 800-series Roomba, with one significant difference. When the vacuum is in refresh charge mode it will only flash yellow, not red. The 800- and 900-series also gives you indicator icons that will flash to give you more information about your vacuum’s status. The battery icon flashes yellow when it’s charging, and flashes red when there’s a charging issue.
It’s relatively easy to check whether or not your Roomba is holding a charge. Most Roombas will need about two hours on the Home Base to reach their full capacity. Leave the Roomba on its base, then come back and try to use the vacuum. If it still gives you low or dead battery warnings, it’s time to move on to troubleshooting.
There are a few possible reasons why your Roomba isn’t holding a charge:
Batteries can wear out over time, and this means they’ll hold less of a charge, and eventually will stop holding a charge entirely. If you’ve had your Roomba for a long time, you may simply need a new battery. This is especially likely to be the problem if you’ve noticed your Roomba’s cleaning time per charge going down over the past few months. You can buy a replacement battery for about seventy bucks—much less than getting a whole new vacuum. Just make sure you get the right type of battery for your Roomba model.
The Roomba has self-protecting fail-safes built-in. If the battery is overheating, it will stop charging so as to avoid causing battery failure. Remove your Roomba from the Home Base, turn it off, and carefully feel the battery. If it’s warm to the touch, remove it from the vacuum and set it aside for a little while. If this problem recurs the next time you try to charge the vacuum, you should buy a new battery.
This is less common than a battery that’s too hot, but can also prevent the battery from holding a charge and lead to charging error messages. This is most likely to occur if you’ve had a battery or vacuum in storage or if it was exposed to the elements—say if it took a recent trip in the trunk of your car in the winter. Leave the battery in a room-temperature environment for a few hours, then try charging it again and see if it holds a charge. Brief exposure to cold shouldn’t impact the long-term performance of the battery.
If the circuitry inside the vacuum is damaged, it can sometimes think the battery is dead even when it has a full charge. Unfortunately, there is no at-home fix for this particular issue. If you suspect the circuitry inside your Roomba is defective, you’ll either need to have it repaired or buy a new vacuum.
If the red light is flashing on your Roomba, it doesn’t necessarily mean you have a problem. Double-check what the different indicator lights mean on your particular model then move on from there. Hopefully, this little guide is helpful in getting your Roomba back in working order!