: Water is heated instantly as it passes through the system, providing a "continuous" supply. II. Strategic Sizing: GPM & Temperature Rise
: Preferred by professionals for high efficiency and easier venting options. V. Key Installation Hurdles
On-demand water heaters eliminate standby energy loss by heating water only as it flows through the unit.
Unlike tanks, these units are sized by their ability to handle "peak demand"—the total hot water needed at one time. 1. Calculating Flow Rate (GPM)