First, you have hot water right away when you want it, and in reality, you have endless-hot water. When you turn up the hot water in your shower, bathtub, sink, dishwasher, or washing machine you will get instant hot water.
Flow sensors inside the tankless hot water heater sense when it is needed and switch-on to produce on demand hot water. No longer do people have to wait for half an hour or longer to bathe. Tankless hot water heaters not only give you instant hot water, they give you more time.