The new high-efficiency Marathon Heavy-Duty Electric fromRheemis engineered to provide a low-cost water-heating solution for high-temperature applications in harsh environments. Featuring titanium elements and a seamless blow-molded polybutene storage tank that is impervious to rust and corrosion, the UL-approved Marathon HD offers a 10-year warranty on the tank and a five-year warranty on parts - the longest protections available for harsh water and environmental conditions.

Intended for heavy-duty applications that require high water temperatures, the new unit will consistently deliver water at 170°F and is available in two sizes:
  • 85 gallons, with a first-hour rating of 87 gallons per hour;
  • 105 gallons, with a first-hour rating of 101 gph.
“Other water heaters may provide high water temperatures, but usually at a sacrifice to the tank and element life,” says Rheem specialty product manager Jeffrey Haney. “Marathon HD enables the end user to meet those high-temperature needs, but at lower upfront and operating costs.”

The 85-gallon model has an Energy Factor (EF) of 0.92 and the 105-gallon unit, an EF of 0.91, for an annual operating cost of less than $515, based on Department of Energy test procedures and a national average fuel rate of 10.65¢ per kilowatt-hour. The industry-leading warranty derives from the unique, award-winning construction of the inner tank, featuring the same nonmetallic construction as the Marathon Lifetime Residential Electric Water Heater. (In 2005, the Society of Plastics Engineers presented its annual Consumer Award to the Marathon residential water heater, citing its polybutene storage tank.) The unit’s key components include:
  • Corrosion-resistant inner tank: The seamless, blow-molded polybutene inner tank is wrapped in a structural shell, consisting of multiple layers of filament-wound fiberglass. This construction enables it to resist the rust and corrosion that can curtail the operational lives of conventional storage tanks - especially in harsh water conditions. The nonmetallic tank needs no corrosion-fighting anode rod, averting any potential odor problems due to the chemical makeup of the water supply.
  • Energy-saving insulation: The durable inner tank is encased in 2.5 inches of polyurethane foam insulation, intended to minimize heat loss through the walls of the tank and cut energy consumption. A pipe wrap kit is also provided to maximize energy efficiency.
  • Titanium element: This rugged component also stands up to severe water and climate conditions, offering superior longevity over all other types of elements.
  • Protective outer tank: The tank and insulation are enclosed within a durable, dent-resistant, molded-polyethylene outer jacket. Recessed into the bottom of the jacket, a factory-installed, full-port brass drain valve is kept well out of the way of brooms, scrubbers and other cleaning equipment.
With its long-lasting titanium element, high-temperature polysulfone dip tube and full-flow drain valve for faster draining and complete sediment removal, the new Marathon HD is easy to maintain to peak performance levels. The unit also includes a factory-installed temperature and pressure relief valve and a vacuum relief valve.

Both of the Marathon HD models are less than 67 in. in height and weigh 134 lb (85-gal model) and 152 lb (105-gal model), respectively, making them easy to maneuver on the jobsite.