what's the BTU rating for indirect tank

lost11

I'm a little confused as to why indirect tanks have BTU input ratings. https://www.supplyhouse.com/Indirect-Water-Heaters-1731000

mikeg2015

That way you know how much boiler capacity is will consume in those conditions and to achieve the rates output. Also gives flow rates at those ratings.

If your flow is too low you can end ok with too cold of return water for a cast iron boiler. If flow is too high you hurt efficiency with high return water temps.

You can also use those numbers so you know what the continuous rating is. So if you have a 70f temp rise then at 140,000 boiler input you get 4gpm continuous.

Zman

lost11 said:

I'm a little confused as to why indirect tanks have BTU input ratings. https://www.supplyhouse.com/Indirect-Water-Heaters-1731000

It is a general guideline based on a specific boiler size.
The continuous output will be BTU/Hr=delta t x GPM X 500, assuming the indirect coil is large enough (rated for your boiler size or larger)

JohnNY

All indirect water heater numbers are to be taken with a grain of salt in my experience. Ever try to cross reference one to another? The numbers are intentionally misleading and require great interpretation.