State Water Heater Water Heater Brochure

TANKLESS MODELS GROUND

WATER TEMPERATURE FACTOR

The temperature of incoming ground

water (cold water inlet temperature)

varies greatly throughout the U.S. and

also ﬂuctuates with the changing of the

seasons. The temperature of water as it

enters the water heater will determine the

amount of “temperature rise” required

to achieve the desired hot water outlet

temperature (120°F is recommended).

The best way to measure incoming

ground water temperature is to use a

thermometer to measure cold water

temperature during the coldest

season of the year. To simplify the

process, use this map to determine

whether your installation location is

in the Southern Zone, Central Zone or

Northern Zone.

PEAK HOT WATER DEMAND

The next step is to determine how

many gallons per minute of hot

water will be required during the

busiest usage period (peak demand).

Consider all appliances and ﬁxtures

that use hot water, including lavatory

faucets, kitchen faucets, washing

machines, dishwashers, showers

and bathtubs. Be sure to determine

how many appliances and ﬁxtures

will be used at the same time (peak

demand).

Remember, these are general recommendations. Your State Water Heater Specialist can review your

family’s needs in even greater detail to make sure the model you choose will always provide enough hot

water to meet the demand.

AVERAGE GROUND WATER TEMPERATURE

SIMPLE TANKLESS SIZING

Average Ground Water

Temperature: 52°F to 61°F

Average Ground Water

Temperature: 37°F to 51°F

NORTHERN ZONE

Average Ground Water

Temperature: 62°F to 77°F

SOUTHERN ZONE

CENTRAL ZONE