Hot Water Button 3 IN 1 Water Dispenser. The water dispenser can make hot, cold, warm water. Heating is rapid, automatic temperature control. Heating time: 6 minutes. Heating maximum temperature: 90℃. Cold Water Button Cooling time: 40 minutes. The yellow light(COLD) on means it's in preocess of cooling. Getting cold water until the yellow light gets off. (Cooling time: 40 minutes, cooling minimum temperature: ±10℃) When the temp is above about 10℃(there's a eletronic element testing the temp), the yellow light automatically gets on and it's in cooling again.