Marathon Tankless Water Heaters

Marathon doesn't currently ship any tankless water heaters in the lineup we track. If you're shopping for tankless water heaters, see the full Tankless category for cross-brand options.

About Marathon

Marathon (Rheem) — subsidiary of Rheem. Specialty water-heater manufacturer serving the US market.

For the complete Marathon lineup across all sub-types and capacities, see the Marathon Water Heaters hub.

Other Tankless water heaters brands

If you're cross-shopping tankless water heaters beyond Marathon, the following brands also ship in this category:

• Rheem Tankless
• AO Smith Tankless
• Bradford White Tankless
• Rinnai Tankless
• Ruud Tankless
• Navien Tankless
• Noritz Tankless
• Bosch Tankless

About Tankless Water Heaters water heaters

Tankless water heaters (also called on-demand or instantaneous water heaters) heat water as it flows through the unit, eliminating the storage tank entirely. The trade-offs are clear: endless hot water, lower operating cost over a long ownership horizon, and a much smaller footprint — at the cost of higher upfront price and more demanding install requirements (gas line sizing, venting, electrical load). With roughly 1,581 monthly US searches for "tankless water heater," this is one of the most-shopped sub-types in the category.

Tankless splits into two fundamentally different products: gas tankless (condensing or non-condensing) and electric tankless. They serve different households.

Gas tanklessFor the complete tankless buyer's guide (all brands, full comparison framework), see the Tankless Water Heaters category hub.