Http://www.mrcoffee.com/InstructionManuals.aspx. Mine says to run Mr. Coffee Cleaner or 20 oz of vinegar in the water chamber on the clean setting.
I Have A Mr. Coffee Maker With A Clean Mode And Don't Know How To Use It Could You Please Tell Me How It Works?
Fill with water but no coffee or filter. Click the mode button until
the red light next to clean is illuminated (not "brew now", "strong",
or "regular").
The water will be heated and run through the system.
Dump out the water from the carafe when the process has finished and the
red light has turned off. Rinse the carafe and the filter holder and
your ready to go. It's supposed to remove mineral build up from your
water supply, I believe. Enjoy!
Call a store who sells these coffee makers and tell them your situation. Sometimes they may let you purchase an instruction manual separately.