A tankless gas water heater is an appliance for providing hot water on demand. By only heating water when it’s needed, tankless gas water heaters save homes money by avoiding the need to continuously keep a tank of water heated.
In a standard tank system, a large volume of water is kept continuously heated and ready for use. If no hot water is needed, the energy used to keep the water hot is wasted. In a tankless system, water is heated only when required, using energy more efficiently. A tankless gas water heater heats water by using a heat exchanger to heat the water as it passes through. When a hot water tap is opened, it triggers the heat exchanger to fire a gas burner and begin heating the water.
Tankless water heater systems are generally designed to service either a single location or an entire house. Single location systems are smaller and usually electrically powered because they can be located close to where they are needed. A gas tankless water system would be used to provide hot water for the whole house due to the greater energy requirement of heating water to circulate throughout the structure.
Although a tankless gas water heater is more expensive to install than a standard tank system, it can provide a nearly endless supply of hot water, while making more efficient use of energy.