Tankless Water Heater

Tankless are also available and gaining in popularity. These tankless water heaters heat the water as the water flows through the device, and do not retain any water internally except for what is in the pipe. Tankless water heaters may be installed in at faucet or bathroom that is far from the central water heater or larger models can be used to provide hot water for the entire house.

Tankless water heaters can be far more efficient than storage water heaters. In both kinds of installation, the absence of a tank saves energy as conventional water heaters have to reheat the water in the tank as it cools off. With a central water heater of any type, water is wasted waiting for water to heat up because of the cold water in the pipes between the faucet and the water heater.

Point of use tankless water heaters are located right where the water is being used, so the water is almost instantly hot, which saves water. They also save even more energy than centrally installed tankless water heaters because there is not any hot water being left in the pipes after the water is shut off. However, point of use tankless water heaters are usually used in combination with a central water heater, as the expense of buying a heater for every kitchen, laundry room, bathroom or sink, often outweighs the money saved in water and energy bills. In addition, point of use water heaters are almost always electrical, and electricity is far more expensive than propane and natural gas.

The most cost effective configuration is usually to use a central tankless water heater for the most of the house, preferably natural gas, and install a point of use tankless water heater at any distant faucets or bathrooms. However, this may vary according to how much electricity, gas and water costs in the area, the layout of the house and how much hot water is used. Only electric tankless water heaters were available at first and they are still used for almost all point of use heaters, but natural gas and propane heaters are now common.

Since the water must be heated instantly, the tankless water heaters use a lot of electricity or fuel while they are on. If a storage water heater is being replaced with a tankless one, the size of the electrical wire or gas pipeline may have to be increased to handle the load.