Available from National Combustion ...

Available from National Combustion Company Inc. is its Super E high-efficiency water heater.
The company says the unit is rated at 95-percent efficiency, meaning savings of thousands of dollars a year through the whole extent of the operation of conventional water heaters.
A stainless poniard storage tank with internal cupro-nickel heat exchanger, the Super E is fired by way of a power gas burner. Combustion is in such a manner complete, Natco says, that it can reach naught parts per million of CO with stack temperatures of 100 to 130 F