If a Keurig coffee maker is not working properly, the company may send a replacement if contacted at 866-901-BREW. Often, the machine quits working because of a sensor in the water reservoir, and the reservoir simply needs to be removed and dropped back into place.
A Keurig coffee maker stops brewing if the machine does not sense a water reservoir, so removing the reservoir and placing it back into the machine may allow brewing to resume. Sometimes the machine resumes normal function if left unplugged for some time and then given plenty of time to warm up before brewing again. If the machine brews less than a full cup of coffee, chances are that the Keurig has a clogged water line. This issue may be easily resolved by running the machine several times without a K-cup.
Mineral deposits within the Keurig are common when hard water is used to brew coffee, making it necessary to descale the machine. To do this, pour undiluted white vinegar into the reservoir and run four cycles on the machine without K-cups. The machine should be left with vinegar in the system for four hours. After four hours, run several cycles of water through the system. Sometimes these mineral deposits simply clog the machine's needle, and can be simply unclogged by pushing a paperclip through the top of the needle.