a direct contact water heater is provided having an upright , closed cylindrical tank formed from an outer tank shell . the outer tank shell has a top , a bottom and an external sidewall extending between the top and bottom to define an interior of the tank . a combustion chamber is centrally located within the interior of the tank . combustible fuel is introduced downward from a combustion means into the combustion chamber and is ignited in the presence of air within the combustion chamber to create products of combustion . a plurality of spray nozzles are connected to a water supply to be heated . the spray nozzles are evenly spaced around and along the length of the combustion chamber for directing water from the water supply into the combustion chamber so that more uniform contact of the water is achieved with the products of combustion to facilitate heating of the water .