Charging Error 121: All Roomba® Models

Charging error 121 indicates the robot is on the dock, but it is losing charge instead of staying charged up. The most common cause is that the dock contacts need maintenance.

To resolve this issue, please start by cleaning the charging contacts:

1. Unplug the dock and wait 60 seconds.
2. Remove the robot from the charging station and place the robot upside down on a flat surface.
3. Grab a lightly dampened melamine foam, such as a Magic Eraser, or a lightly dampened cloth.
4. Clean the metal charging contacts on your robot and dock. They should have a visible shine.

Click here to see the charging contacts for Roomba® 100/1000 Series:

Vac/Combo Robot Charging Contacts	Dock Charging Contacts	AutoEmpty™ Dock Charging Contacts

 

Click here to see the charging contacts for Roomba® 200/2000 Series:

Vac/Combo Robot Charging Contacts	Dock Charging Contacts

 

Click here to see the charging contacts for Roomba® Plus 400 & Plus 500 Series:

Combo Robot Charging Contacts	AutoWash™ Dock Charging Contacts

 

Click here to see the charging contacts for Roomba® Max 705 Vac:

Vac Robot Charging Contacts	AutoEmpty™ Dock Charging Contacts

 

Click here to see the charging contacts for Roomba® Max 705 Combo:

Vac Robot Charging Contacts	AutoEmpty™ Dock Charging Contacts

 

Note: Damaged contacts could also prevent your robot from charging. If the contacts are green or copper colored, they are damaged and the robot or the dock with the damaged contacts needs to be replaced.

Make sure power is going to the dock by checking the power cord connections, both on the wall and on the dock. Unplug both connections and plug them back in.

If the issue persists, the most likely cause is that the battery has not been properly installed, so power is not reaching the battery. Please remove and reinstall the battery from the robot to clear the charging error 121.

If the error persists after following all the steps outlined above, contact iRobot Customer Care for additional assistance.

For expedited service, please have the following ready:

• Your robot charged and with you
• Your robot's Serial Number
• For warranty claims: Proof of purchase (receipt or invoice for purchase from an authorized retailer)