Uniform Energy Factor refers to a water heater's efficiency when run under simulated heavy use conditions for a 24-hour period. Electric Tankless is part of the Water Heaters test program at ...

Tankless water heaters are not rated for FHR; look instead for gallons per minute. Size: If you’re replacing a current gas or electric storage-type heater, you can purchase the same size as the one ...

The fuel type affects the water heater's size, capacity, and operation costs. There are also some differences in efficiency.