Pull off the drip tray and the little baffle that catches splashes. You know, that plastic grate you never look at. Wash those pieces in hot, soapy water and set them aside. They’re small and easy to forget, but they’re basically petri dishes in disguise.
Now, look at the main reservoir—the empty tank where the big bottle usually sits. If you see crusty white stuff (that’s calcium), congratulations! You’re about to clean the heck out of it. Don’t be embarrassed; it’s just hard water doing its thing.