What is more efficient to bring water to a boil? 1. Using the low setting on heat 2. Going full blast to get it to boil as fast as possible For a vehicle, developing velocity is more economical with slow accelaration, but would it be the same with boiling water? Does it take less BTU to crank the heat slowly until it reaches a boil or put it on high right away? This question relates to a 50 000 BTU gaz burner to heat 40 liters of water for canning pickles.