I have a gas water heater that has an exhaust of 475 degrees Fahrenheit. I would like to know, what formula can I use to determine the amount of BTU's that the water heater produces (or wastes) per hour of use. I only have the temperature of the exhaust (475 Deg. F) and the diameter of the flue which is 3". I would appreciate any help or guidance. Thank you.(adsbygoogle = window.adsbygoogle || []).push({});

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# How do I calculate BTU?

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