Tankless Gas Water Heater Sizes

Use our handy calculator to determine your needed flow rate and temperature rise then find models that match your needs.

Tankless gas water heater sizes.

How to determine the required size of a tankless hot water heater. Determine your water flow rates. Simply locate the appropriate water heater sizes on ecomfort using your information. You ll need to raise the incoming water temperature from 40 degrees to 105.

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. Rinnai super high efficiency plus 9 8 gpm indoor natural gas tankless water heater. Determine the mounting space. Looking to purchase a new tankless water heater but having trouble figuring out what size or model you need.

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. Like a hot water tank for 5 people will require at least a 60 gallon tank. So you ll need a tankless water heater that can produce at least a 60 degree rise in temperature at 5 2 gallons per minute. Since tankless water heaters supply endless hot water you don t have to worry about capacity but instead think in terms of water flow rate.

Just follow the three simple steps below to choose the right model and size you need. Tankless water heaters are much smaller than units with a storage tank allowing them to be wall mounted. Rinnai tankless water heaters are designed to provide maximum performance and efficiency using either a 3 4 or 1 2 gas line as long as sufficient gas flow is available. Gallons per minute gpm is the key when it comes to sizing tankless water heaters.

Measure your cold water temperature. You ll need to be able to heat at least 5 2 gallons of water. Below we ve highlighted what size water heater you would need in our example of 6 5 gpm at a 63 f temperature rise.