URNEX® DEZCAL™ descaling powder, (4) 1 oz packets, for all BUNN® brewers and water heaters. Mineral scale buildup on the heating element of all hot water, coffee and tea equipment can clog the water flow, prevent the full flavor extraction from the coffee beans or tea leaves, and can cause a machine to stop working. Odorless URNEX® descaling powder removes mineral scale buildup and rinses away thoroughly, unlike vinegar which takes longer to be effective and leaves behind an unpleasant odor and aftertaste that impacts the aroma and taste of your coffee and tea.