Indirect Tank Sizing

Indirect water heaters are sized by the total hot water use required. If you have one very large draw like a hot tub, it may be more beneficial to size that on a separate hot water appliance. Once you determine the hot water gallons needed compare the tanks first hour rating and boiler size.

This is for residential applications only.


When you do all the math compare it to the first hour rating of the chosen indirect.

Now chose the tank size from the manufacturers indirect chart

The choice would be an MS2-030 in this example. This should work on any indirect water heater tank with an internal coil.

Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed on a per job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accepts no responsibility for improper information, application, damage to property or bodily injury from applied information found on this website as it should be reviewed by a professional.