Question: how many btu does it take to boil a gallon of water?
Answer: What is a BTU? A BTU (British Thermal Unit) describes the amount of energy to raise 1 lb of water 1 degree Fahrenheit in one hour. Water equals 8.3 lbs per gallon. To boil one gallon of water starting 70°F in 1 hour you will need 8.3 x (212-70) = 1,178.6 BTUs.