How to Select a Water Heater


It is important to replace your existing water heater with one that is compatible with your home. There are several criteria you should consider before selecting a water heater. Use this guide to decide which storage-tank water heater would be best for your home.

Fuel Type

Gas water heaters: Gas water heaters use a burner at the bottom of the tank to heat water. They require ventilation to direct exhaust gases out of your home.

  • Natural Gas vs. Liquid Propane - Natural gas is far more common than liquid propane. Natural gas is delivered to your home through underground piping, while liquid propane is stored in a tank and typically used in areas without natural gas.
  • Ventilation - Most gas water heaters use a vertical vent or chimney. If your water heater has a horizontal vent outside, you will need a specialized direct vent or power vent model.
Electric water heaters: Electric water heaters use electrical heating elements instead of a gas burner and do not require ventilation.
Location and Size
Location - Replacement water heaters need to fit in the same spot in your home. If not, installation will require significant and often expensive changes to plumbing and gas or electrical wiring. Take note if your current water heater is in a tight space like a closet or attic, or if it is in an open space like a basement.
Dimensions - Before buying, measure the height and width of your current water heater. Keep in mind water heaters come in tall and short sizes and vary in width.
Capacity - Most homes have 40- or 50-gallon capacity water heaters, although capacity ranges from 30 to 80 gallons.
Other considerations
Amount of Hot Water - The “first hour delivery" rating measures the amount of hot water the water heater can provide in its first hour of use. If your home runs short of hot water, consider a water heater with a greater tank capacity and a higher recovery rate.
Warranty - Water heaters come with different warranty options as well as a variety of extended protection agreements.
Energy Efficiency - ENERGY STAR® water heaters save money over time and may be eligible for state tax credits and local utility rebates. To qualify as Energy Star, gas water heaters must meet a minimum .67 energy factor and electric water heaters must be heat pump hybrids. Energy factor is a measure of water heater efficiency, and considers the amount of heat lost to surrounding air (standby energy loss), how effectively heat transfers from the energy source to the water (recovery efficiency), and the amount of heat lost as water circulates through the tank (cycling loss).