Frying apparatus for frying food, such as French fries, vegetables, bakery goods, meat fish, poultry and the like, in a heated fluid contained in a fry pot. The fluid is heated by a combustion burner that has a heat exchanger removably disposed in the heating fluid. When removed from the fluid, the heat exchanger and the fry pot can be easily cleaned. The air and/or gas is injected into the combustion chamber so as to provide an air gas ratio that supports clean combustion. A control monitors various temperatures and other parameters at various locations of the frying apparatus to control the efficiency of the frying apparatus to approximate a predetermined efficiency by altering the air/gas ratio.