THE QUESTION IS NOT WELL ANSWERED WHEN THE COFFEE MAKES IT WORK WHEN ALL THE WATER PASSES.
WHEN I BUY IT IT SEEMS THAT IT WAS MADE IN 30 MINUTES BUT NOW IT LONGS LONGER. DUE TO THE PIPE WHERE THE WATER PASSES THE HEAT THAT IS HEATED BY A RESISTANCE AND IS EXPULSING SQUARES OF THE SAME IS STILL HALF COVERED.
You just asked how long it takes to make a liter of coffee since you had made a descalsification? I would do it by disassembling the coffee maker at the bottom, disconnecting the resistance sleeves and passing a wire or something similar until it is completely clean.