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Its award-winning construction makes the Marathon® water heater the most durable Rheem® electric water heater ever made. And its industry-best warranty makes it a smart purchase you can count on for years to come.

Unmatched Durability

Our patented insulation process, seamless liner and tough outer jacket make Marathon the most durable in the business

Simple Installation & Service

Unique design allows one-person installation for fast service, lower costs and quick maintenance

Lightweight Design

Marathon’s lightweight tank is easier to maneuver and position, and features a bowl tank that drains completely

Lifetime Tank Warranty

Tank is built to last for as long as the homeowner owns their home, and backed by a lifetime warranty1


Marathon & KwikComfort Deliver a Legacy of Savings

Residential KwikComfort® Financing makes it easy and smart to enjoy hot water that lasts a lifetime. With low monthly payments, your Marathon Water Heater will only make a small impact on your monthly budget. And because it’s built to last, your Marathon will still be going strong long after it’s paid off.

Unmatched Durability

Explore the strength of Marathon’s features below:

  • Dry Fire Protection

    Advanced circuitry ensures that heating elements only turn on when surrounded by water, prolonging their life.

  • Patented Insulation Process

    2.5″ polyurethane insulation reduces heat loss for greater energy efficiency.

  • Seamless Plastic Liner

    The Marathon water heater features a seamless, blow-molded plastic inner tank, so it won’t rust or corrode.

  • Tough Outer Jacket

    Multiple layers of filament wound fiberglass give the tank unmatched strength.

Rheem Marathon Water Heaters: Built for a Lifetime [3:25]

Many Marathon Sizes to Fit Your Needs

Point-of-Use Water Heater

15- and 20-Gal. Capacities

Standard Water Heater

30-, 40- and 50-Gal. Capacities

Thermal Storage Tank

50-, 85- and 105-Gal. Capacities

Nothing Compares to Marathon

See the comparison by clicking the appropriate tab below:

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Tab Title here

Marathon Plastic Tank Competitor Stainless Steel Tank
Number of Replacement
Units Allowed
Perpetual 1 Per Customer
Warranty Restriction Due
to Water Condition
No Yes
Warranty Restriction Due
to Water Temperature
No Yes
Warranty Transferable1
Low Product Weight
Dry Fire Protection
Element Titanium Stainless Steel
Dent / Corrosion Resistant Jacket
Saltwater-Resistant Jacket

Marathon Plastic Tank Rheem Standard Electric Tank
Lifetime Savings on Water Heater
$1,1972 0
Low Product Weight
Dry Fire Protection
Element Titanium Copper
Anode Rod No Yes
Corrosion Resistant
Warranty1 Lifetime 6 Years
Lifetime5 Water Heater Needed 1 8
Dent / Corrosion Resistant Jacket
Saltwater-Resistant Jacket

Get a Rheem Marathon Today

Ready to enjoy a lifetime of hot water?