How Water Heaters are Rated
Hot water

Looking at buying a new water heater?

If you are looking at buying a new water heater,  the best way to compare models is by looking at the Energy Factor (EF) rating.

If you look for a yellow tag on the side of the water heater, standard tank-type electric water heaters have Energy Factors of between 0.90 and 0.95. The new crop of heat pump water heaters have EFs of 2.0 to 2.5, making them roughly two to three times more efficient at heating water.

Also several of these models meet ENERGY STAR requirements and may also qualify for a federal tax credit.