Robert North posted an answer for this DeLonghi Coffee Makers & Espresso Machines:
"I have the same problem. I think it's a factory defect. The descale button doesn't work,..."
Robert North posted an answer for this DeLonghi EAM3500 Espresso Machine/Coffee Maker:
"I have the same problem. The descale cycle won't start when I hold down the descale..."
Robert North posted an answer for this Cuisinart Grind and Brew 10 Cup Coffee Maker:
"Citric acid seems to be a lot better than vinegar (dilute acetic acid) for descaling. I..."