Snow is loaded into a water-filled melting tank incorporating a gas or oil fired burner system. The burner fires downward, directing heat and hot combustion gases along a stainless steel tube which is submersed below the water line. The gases exhaust directly into the water, exchange their heat, and rise up a weir tube in the form of millions of bubbles. This turbulent action creates an airlift which carries warm water up to the weir tube. At the top water is sprayed over the snow to promote further melting. The operating concept provides excellent mixing and agitation, and maximum thermal efficiencies of close to 100% are achieved.