What Size Tankless Water Heater Do I Need

You currently have a 30 40 50 or even 80 gallon water heater and want to replace it with a tankless water heater.

What size tankless water heater do i need. Instead they heat it as it s needed. What size tankless water heater do i need to replace a 50 gallon water heater. Tankless units work by using built in coils to heat water when you need it meaning you ll always have hot water on demand. A tankless water heater albeit more expensive upfront will provide you with hot water no matter what.

If you do the math for 50 temperature rise you need approximately 25 000 btu s per hour per gpm of water required which doesn t take heater efficiency into account but gives a good idea of the size of high efficiency heater needed. Tankless water heaters are rated by the maximum temperature rise possible at a given flow rate. Flow rate is the key spec when sizing a tankless water heater o brian says. This makes these types of water heaters more efficient than traditional storage tank water heaters which could end up reducing your energy bills.

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. 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. Tankless water heaters do not store hot water. 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.

Below we ve highlighted what size water heater you would need in our example of 6 5 gpm at a 63 f temperature rise. How to size a tankless water heater. Example 1 here is how this situation goes. If you haven t yet considered what type of water heater might be best for your home learn more about selecting a new water heater.

Sizing tankless or demand type water heaters. The first factor in choosing a tankless water heater is calculating the size of your hot water heater. Therefore to size a demand water heater you need to. Once you have your total flow rate and the required temperature rise you can find the right size tankless water heater for your home.

Therefore to size a demand water heater you need to determine the flow rate and the temperature rise you ll need for its application whole house or a remote application such as just a bathroom in your home. Tankless water heaters are much smaller than units with a storage tank allowing them to be wall mounted. Electric units have measurements in the 10 inch high to 7 inch wide range while gas fired.