Roomba won't charge: causes and fixes
A Roomba that won't charge usually has a dock with no power, dirty charging contacts, or a battery that needs a reset or replacement. Below are the fixes from iRobot's support pages, matched to the light or charging error you see.
Researched by Riley Hart · updated Oct 27, 2026 · How we research
Most Roombas that won't charge have a dock with no power, dirty charging contacts, or a robot that is not sitting on the contacts. Start by checking the dock light and wiping the contacts on the robot and dock with a lightly damp melamine foam or cloth. On a new Roomba 100, 200 or Max 700 series robot, iRobot says to hold POWER for 30 seconds off the dock and then dock it within 4 minutes. If the app shows a charging error number, the battery may need reseating or replacing.
| What you see | Likely cause | Fix |
|---|---|---|
| No dock light | Dock has no power: loose cord, dead outlet or damaged cord | Unplug and firmly replug the cord at both ends, test the outlet with a lamp, replace a damaged cord, or the dock if the cord is fine |
| Dock light off with robot on it | Robot not lined up with the charging contacts | Lift the robot and set it back, wiggling until it beeps; check it faces the right way; on Roomba 200 and 2000 leave about 1/2 inch between bumper and dock |
| Charges only sometimes, Error 21 or 121 | Dirty charging contacts | Unplug the dock and clean the contacts on robot and dock with lightly damp melamine foam or a lightly damp cloth |
| Green or copper colored contacts | Damaged charging contacts | Contact iRobot Customer Care; the robot or dock may need replacing |
| New robot shuts off, battery % not rising | Robot still in ship mode (100, 200, Plus 400, Plus 500, Max 700 series) | Off the dock, hold POWER at least 30 seconds, release, then dock it within 4 minutes |
| No lights on the robot | Robot asleep, or it needs a reboot | Wake it by placing it on the dock; if that fails, remove and reinstall the battery and dock again |
| Charging Error 1, 8 or 101 | Battery not detected or not talking to the robot | Confirm it is a genuine iRobot battery, then remove and reinstall it |
| Charging Error 6, 7, 106 or 107 | Battery too hot or too cold | Bring the robot to room temperature and try again |
| Charging Error 9, 11, 20 or 114 | Battery fault or failure | Reinstall the battery (for Error 20, leave it out 15 minutes first); replace the battery if the error returns, and always for Error 114 |
| Full charge but short runs | Worn battery | Run iRobot's runtime test on hard floor; replace the battery if it runs under 60 to 90 minutes, depending on series |
| Error 18, cannot find the dock | Dock badly placed, dirty docking target or wheel problem | Put the dock on a hard level floor against a wall, 4 ft from stairs; clean contacts and docking window; reboot |
From iRobot's Roomba not charging article, charging error chart, short runtime article and Error 18 article, checked October 27, 2026. Error numbers 1 to 21 show in the iRobot HOME app; 101 to 121 show in the newer Roomba Home app.
If the same code comes back after the fix, contact iRobot support first, especially under warranty. Out of warranty, compare the repair quote with a new robot's price and 3 year cost.
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Step by step checks, in order
iRobot's own not charging guide works from the outlet to the battery. Do the checks in this order, because the early ones are free and fix most cases.
Look for a dock light first. A lit dock means it has power. Some docks have no light at all: the Roomba Essential, the 200 and 2000 series, and the 100 and 1000 series with the standard dock. On an AutoEmpty dock, lift the lid and pull up the bag tag; iRobot says the light should turn red if the base has power.
- Unplug the power cord from the outlet and from the dock, then plug both ends back in firmly.
- Test the outlet with a lamp or phone charger. If it is dead, use another outlet.
- Unplug the dock and clean the charging contacts on the dock and under the robot with lightly damp melamine foam or a lightly damp cloth. iRobot says to use only those two materials.
- Clear hair from the brushes, the gray bearings and the front caster wheel, since a dragging robot can stop short of the contacts.
- Set the robot back on the dock. The dock light should come on for about 4 seconds (60 seconds on Combo 10 Max and Essential 2 docks) and the robot should beep.
- If the robot has no lights, take out the battery, put it back and dock again. iRobot says this reboots the robot and clears errors.
Read the charging error number
If the app shows a charging error, the number tells you where to look. Errors 4, 5, 21 and their 104, 105 and 121 versions point to the charging contacts, so clean them. Errors 6 and 7 mean the battery is too hot or too cold. Errors 1, 8, 9, 11 and 17 point to the battery itself, often a battery that is loose or not a genuine iRobot part.
Error 19 means charging timed out; iRobot says to reinstall the battery and clean the contacts. Error 20 means the battery is not ready to charge; leave it out for 15 minutes before putting it back. Error 114 is an internal battery failure, and iRobot's only fix is a new battery. See our full Roomba error codes page for non charging errors.
When to replace a part
Replace the dock power cord if it is cut or frayed. If the outlet works and the cord looks fine but the dock still gets no power, iRobot says the dock needs replacing and you can keep the old cord.
Replace the battery when charging errors like 9, 11 or 20 keep coming back, or when the robot runs short on a full charge. iRobot's runtime test is simple: charge fully, unplug and hide the dock, and time a run on hard floor. Minimums are 90 minutes for e series, 75 minutes for 900, i, j, s and m series, and 60 minutes for 400 to 800 series. Buy a genuine iRobot lithium ion battery, since several error codes flag batteries that may not be genuine. A new battery has to be woken up on the dock before first use.
Owner fix: iFixit's repair wiki says many owners replace the battery once it is one to two years old and runtime has dropped, and rates the swap as moderate, about 15 to 30 minutes.
When to contact iRobot support or use the warranty
Contact iRobot Customer Care if the charging contacts look green or copper colored, if the robot shows no lights after a battery reset, or if the dock light never comes on with a known good cord and outlet. Have the robot, its serial number and your proof of purchase ready for a warranty claim. If the robot is still under warranty, iRobot says to call Customer Care before buying a battery yourself.
When a new robot makes more sense
A battery is a normal wear part, so a new battery alone is usually worth it. If an older Roomba needs a new battery and a new dock at the same time, or support confirms a fault inside the robot, compare that cost with a current model in our robot vacuum rankings before you pay for repairs. Note that iRobot's service replacement robots ship without a battery, so you move your old one across.
Questions people ask
Why is my Roomba on the dock but not charging?
Usually dirty charging contacts or a robot that is not sitting squarely on them. Unplug the dock, clean the contacts on both with a lightly damp melamine foam or cloth, then reseat the robot until it beeps and the dock light shows.
How do I wake up a new Roomba that won't charge?
On 100, 200, Plus 400, Plus 500 and Max 700 series robots, iRobot says to take it off the dock, hold POWER for at least 30 seconds, release, and put it back on the dock within 4 minutes. It can take over 30 seconds to boot.
How do I know if my Roomba battery is bad?
Charging errors like 9, 11, 20 or 114 point to the battery, and so does a run that ends with a low battery error before iRobot's minimum runtime of 60 to 90 minutes on hard floor.
What does a red light on my Roomba mean when charging?
iRobot says a red light means the battery is too low to start. Leave it on a powered dock. If it never changes, follow the contact cleaning and battery reset steps.
Can I use a non iRobot battery?
iRobot's charging chart has errors for batteries that may not be genuine, and its fix is to install a genuine iRobot battery.