Empty your coffee maker: Make sure the carafe is empty and clean, and that the grounds have been cleaned out of the chamber.
Make the cleaning solution: Fill the carafe with equal parts white vinegar and water.
Pour it into the water chamber: Fill the chamber all the way to its capacity.
Run half of a brew cycle: Start a brew cycle. Midway through the brew cycle, turn off the coffee maker and let it sit for an hour. Note: This is for especially bad buildups (if you haven’t cleaned your machine in ages). If you do this regularly, you can probably get away without the rest period.
Finish the brew cycle: After an hour, turn on the coffee maker and let the brew cycle finish.
Rinse: Pour out the vinegar-water solution and rinse the carafe.
Run a water cycle: Fill the chamber with just water and let the machine run. Repeat two more times, allowing your coffee maker to cool slightly between brews. This will get rid of any lingering vinegar smell or flavor.
Some machines have cleaning cycles. However, if not, fill the reservoir tank with the white vinegar/water mix and run the maker until the reservoir is empty. It helps to 'make' coffee at the largest possible setting.