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Marathon Lifetime 75-Gallon Electric Water Heater

Model MR75245
4.6/5 from 340 ratings
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Kw
4.5
Voltage
240V
Amperage
30A
Fuel Type
Electric
Tank Type
Tank
Energy Factor
0.93

Marathon Lifetime 75-Gallon Electric Water Heater Review

The Marathon Lifetime 75-Gallon Electric is a larger-capacity variant of the standard Marathon line. Polybuthylene-tank construction with lifetime tank warranty. Sized for 5+ person households or homes with overlapping demand requiring more reservoir than the 50-gallon provides.

Specs: 75 gallons stored, two 4500W heating elements (240V), UEF 0.93, 89-gallon first-hour rating, lifetime tank warranty + 6-year parts warranty. Polybuthylene fiberglass-reinforced plastic tank (no anode rod required). About 51" tall × 28" diameter — shorter than 50-gallon but wider.

The Marathon's defining feature is the polybuthylene tank construction. Unlike glass-lined steel that fails by rust-through at year 10-15, the polybuthylene tank has no iron to oxidize. Real-world Marathons from the early 1990s are still in service 30+ years later.

The 75-gallon capacity covers households of 5+ people in primary residences. The Marathon's lifetime warranty makes it the highest 30-year ownership value in the electric tank category — buyers staying in the home long enough to need two replacements of a standard tank should have bought one Marathon instead.

About $2,499 unit, $3,000 installed. Right buyer: large family in a long-stay primary residence (15+ years), particularly in hard-water regions. Wrong buyer: short-term residences (5-7 year horizon), small households (50-gallon serves adequately), or homes where heat-pump installation is feasible (heat-pump operating cost is 75% lower).

Pros
  • No combustion, no venting required — installs anywhere with 240V electrical access
  • Strong UEF 0.93 efficiency — approximately 20% lower annual operating cost vs 0.62 standard
  • 99-year warranty — top-tier coverage for residential water heaters
  • 75-gallon capacity — right-sized for 3–4 person households with standard usage patterns
Cons
  • Resistance electric has slower recovery than gas at comparable capacity — schedule heavy use to match tank recovery

Full Specifications

Brand
Marathon
Model Number
MR75245
Kw
4.5
Voltage
240V
Amperage
30A
Fuel Type
Electric
Tank Type
Tank
Energy Factor
0.93
Warranty Years
99
Capacity Gallons
75
First Hour Delivery
99

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