Reply To: How long will a hot water dispenser dispense hot water?

It depends on the wattage, and on the cleanliness of your water. The ISE is not designed as an instantaneous heater, since it has a tank. And the heating element is subject to decline with corrosion. If there is lime and magnesium in your water, the reheat time will get increasingly long. It also depends on the temperature of the incoming water and effiency of heat exchange.