Tankless Water Heaters versus Tank Water Heaters

Tankless water heaters save money simply because for most of the day the water heater is OFF and not using any energy. Tankless water heaters also last way longer than tanks. Not because they are made of special materials, but rather because for most of the time they are OFF. Tank type water heaters go on and off all day long to keep water hot whether it is being used or not. This is very inefficient and over time it wears out the heating element. When you wake up each morning the pipe between your water heater and your shower is full of cold water. Whether you have a tank or are tankless water heater you still have to push a "slug" of cold water through that pipe before you get hot water. When you had a traditional hot water tank the cold slug of water in that pipe was back filled immediately by the waiting hot water from the tank. Once you have a tankless there is an additional amount of cold water in the tankless water heater that adds to that slug of cold water. The tankless water heater turns on immediately when it senses a hot water demand, but it does take a few seconds to push that extra amount of cold water that is in the tankless water heater's heat exchanger through your pipe. This usually amount to an additional few seconds of wait time before you get hot water out of your shower head. Once you start receiving that hot water in your shower you get to enjoy an endless amount of hot water. And you can have person after person in your household take consecutive showers without ever having to worry about running out of hot water. In contrast, tank type hot water heaters have a fixed volume and once the tank has been emptied of hot water the household has to wait for the volume of water in the tank to be reheated. This can take 1/2 hour or longer depending on the volume of the water tank. All of this explains why new "tankless" hot water heaters do not produce "instantaneous" hot water at your tap. The distance from your tankless hot water heater to your tap determines the time it will take for hot water to come out of the tao. One thing that you should notice however, is that once you have used your tankless water heater if you use it again soon thereafter you should get hot water almost immediately. This is because the pipe is now full of a hot water "slug" instead of a cold water "slug".