Ans. To descale a hot water dispenser, follow these steps: 1. Fill the dispenser to the max level and then empty it in a cup. 2. Add citric acid to the hot water cup. 3. Now fill the dispenser with this hot water. 4. Drip all the water into the cup. 5. Discard this water. And repeat steps 2, 3 and 4 until the water level is at the minimum mark. 6. Open the lid and empty the remaining water from the reservoir of the dispenser. 7. Rinse the water dispenser by filling it with clean water. 8. Fill your dispenser with fresh water to the max level and your water dispenser is new as before. Do dispenser cleaning once in a month. Especially if you live where hard water comes to your home.