Electric Instant Hot Water Heater Sizing

If you want to upgrade your water heater size from 40 or 50 gallons storage water heater or replace it you won t necessarily need a big tankless water heater.

Electric instant hot water heater sizing.

The first hour rating is the number of gallons of hot water the heater can supply per hour starting with a tank full of hot water. You need a proportional amount of energy or kw to heat the flow or gpm you need for your application. How to size a tankless water heater. Just follow the three simple steps below to choose the right model and size you need.

The chart below will help you determine the correct electric tankless water heater based on flow rate gpm and temperature rise. Tankless water heater sizing calculator. The right size is a tankless water heater that can heat enough gallons of water to a specific temperature per minute to keep up with the demand. For example you might not be able to run more than one shower at a time without someone getting an arctic blast of cold water.

Tankless water heaters are intended to heat potable drinking water only and the inlet water to a tankless unit should not be pre heated. A tankless water heater creates hot water on demand. Gas tankless water heaters are able to produce a larger temperature rise per gpm than electric models. Having a water heater that is too small will result in it not being able to produce enough hot water for your household demand.

Now you need to understand what temperature rise means. The first factor in choosing a tankless water heater is calculating the size of your hot water heater. In fact it is the most important part of choosing a new unit for your home. Sizing storage and heat pump with tank water heaters.

We already covered gpm. Looking to purchase a new tankless water heater but having trouble figuring out what size or model you need. Before we get to how to use the calculator to size a tankless water heater let s talk about the factors that go into understanding what size inline water heater you need. While traditional tank water heaters are calculated by your family size a tankless water heater is calculated by the quantity and types of fixtures or appliances it will serve.

Choose the right tankless electric water heater for you. Use our handy calculator to determine your needed flow rate and temperature rise then find models that match your needs. Rheem tankless electric water heaters make it easy to enjoy instantaneous continuous hot water space saving design and significant energy cost savings.