Abstract: A combustion burner includes a housing secured to the top of a water heater, a gas tube in fluid communication with a source of gas and depending vertically from the housing and positioned within a heat exchange tube of the water heater. The An ignition assembly depends vertically from the top of the housing through the gas tube and into the heat exchange tube. An angled nozzle, extending from the housing, transports air from an air blower through the housing and into an annulus defined between the exterior of the annular chamber and the interior of the heat exchange tube. A deflector plate having a first and second series of slots and adjacent louvers effects the mixture of the gas and air in the interior of the heat exchange tube and enables the production of a long narrow flame within the heat exchange tube.

Abstract: The present invention is a commercial water heater comprising a tank dimensioned to hold a quantity of water, a blower, a heater, a heat exchanger in the water, and a control system. The heat exchanger includes a central tube running from the top of the tank to the bottom and a coil connected to and encircling the central tube. The heater is mounted inside the central tube, and the blower is mounted to the top of the tank, which together simplify manufacture and servicing. The blower is capable of delivering sufficient air for combustion at a pressure and velocity sufficient to drive the exhaust gases fifty feet beyond the water heater outlet, thus avoiding the need for a chimney. The water heater according to the present invention has an average efficiency of 93% with a 1% standby loss and is considerably cheaper to manufacture than other similarly efficient water heaters.