You are currently viewing Choosing the right size when purchasing a tankless water heater

Calculate Temperature Rise

Temperature rise is the difference between the winter, or coldest, groundwater temperature in your area and the preferred set temperature of your tankless water heater.

Consult a map of the average winter groundwater temperatures to find the temperature in your area. Or, at the coldest time of year in your area, you can measure your water temperature with a thermometer as it comes straight out of the ground (usually, at an exterior faucet).

Determine Peak Hot Water Demand

Peak hot water demand is the maximum amount of hot water that your home may require. It’s not intended to be a realistic number; it’s designed to make sure that your water heater can reach theoretical peak demand.”

Read about choosing the right tankless water heater here.

When calculating how much hot water is used at any one point, you must add up the usage across those fixtures based on gallons per minute. Consider the peak times when hot water is used for your bathroom(s), kitchen, and other appliances like dishwasher or washer. Armed with that information you’ll be able to determine an appropriately sized tankless water heater.

Apple Valley Eagan Appliance offers installation and service to a variety of water heaters. Call us at 952-953-0080 to find out more or ask any questions you may have.