A marine water heater is a specialized unit designed to provide hot water on boats, utilizing a combination of electric power and engine heat exchangers to efficiently heat the water. Available in various sizes, such as 6, 10, or 20 gallons, these heaters are often equipped with thermostats, pressure relief valves, and safety features like anodes to prevent corrosion.
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1-2 weeks delivery time The Isotemp 601531S000003 Slim 15L marine water heater features a 4-gallon stainless steel tank, a 230V/750W immersion heater, and an integrated mixing valve for stable outlet temperature. The heat exchanger and heating element are positioned low in the tank for uniform heating, while dedicated inlet/outlet geometry minimizes cold-water mixing for maximum usable hot-water capacity in compact onboard installations.
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$ 854.34
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1-2 weeks delivery time The Isotemp 602031S000003 Slim 20L marine water heater features a 5.3-gallon stainless-steel tank with a 230V/750W immersion heater and an integrated mixing valve. With the heating element and heat exchanger mounted low in the cylinder, the unit provides uniform heating, while optimized inlet/outlet geometry reduces cold-water mixing to deliver maximum usable hot-water volume in compact onboard installations.
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$ 918.92
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1-2 weeks delivery time The Isotemp 602431B000003 Basic 24L marine water heater features a 6.4-gallon stainless-steel tank, a 230V/750W immersion heater, and a built-in thermostat-controlled mixing valve. With the heater and heat exchanger mounted at the tank’s lowest point for uniform heating, and optimized inlet/outlet geometry to reduce cold-water mixing, it delivers high hot-water output in a compact footprint.
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$ 904.19
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1-2 weeks delivery time The Isotemp 602531S000003 Slim 25L marine water heater features a 6.5-gallon stainless-steel tank with a 230V/750W immersion heater and an integrated mixing valve. With the heating element and heat exchanger mounted at the lowest tank point and optimized inlet/outlet design to reduce cold-water mixing, it delivers maximum usable hot-water capacity in a compact Slim-series footprint.
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$ 999.53
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1-2 weeks delivery time The Isotemp 604031B000003 Basic 40L marine water heater features an 11-gallon stainless-steel tank, a 230V/750W immersion heater and an integrated mixing valve. With heating components mounted at the lowest point for uniform temperature distribution and optimized inlet/outlet geometry that reduces cold-water mixing, it delivers high hot-water output for larger onboard systems.
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$ 1,008.78
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1-2 weeks delivery time The Isotemp 605031B000003 Basic 50L marine water heater features a 13-gallon stainless-steel tank, a 230V/750W immersion heater and an integrated mixing valve. With low-mounted heating components for uniform temperature distribution and inlet/outlet geometry engineered to reduce cold-water mixing, it provides high-capacity hot-water performance for large marine installations.
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$ 1,326.98
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1-2 weeks delivery time The Isotemp 607531B000003 Basic 75L marine water heater features a large 20-gallon stainless-steel tank with a 230V/750W immersion heater and an integrated mixing valve. Low-mounted heating components ensure uniform temperature distribution, while optimized inlet/outlet geometry minimizes cold-water mixing, providing high-volume hot-water output for large vessels and long-range cruising systems.
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$ 1,798.48
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Isotemp 601631QX00000 - 230V/750W Slim Square 16L Stainless Steel Marine Heater without Mixing Valve
1-2 weeks delivery time The Isotemp 601631QX00000 Slim Square 16L marine water heater features a compact 4.2-gallon stainless-steel tank with a 230V/750W immersion heater and an engine-water heat exchanger. Designed without a mixing valve, it provides efficient hot-water production and space-saving installation for small and medium-sized vessels.
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$ 1,063.79
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Isotemp 6P1531SPA0100 - 230V/750W SPA 15L Stainless Steel Marine Heater without Safety, Mixing Valve
1-2 weeks delivery time The Isotemp 6P1531SPA0100 Spa 15L water heater features a 4-gallon stainless-steel inner tank, polypropylene outer casing and a 230V/750W immersion heater. Delivered without a safety valve or mixing valve, it provides a compact, cost-efficient hot-water solution for installations that use external protection and temperature-control components.
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$ 670.85
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Isotemp 6P2031SPA0100 - 230V/750W SPA 20L Stainless Steel Marine Heater without Safety, Mixing Valve
1-2 weeks delivery time The Isotemp 6P2031SPA0100 Spa 20L marine heater features a 5.3-gallon stainless-steel inner tank, durable polypropylene outer casing and a 230V/750W immersion heater. Delivered without a safety valve and mixing valve, it provides a compact, cost-effective heating solution for installations where external protection and temperature-control systems are already in place.
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$ 712.39
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Isotemp 6P2531SPA0100 - 230V/750W SPA 25L Stainless Steel Marine Heater without Safety, Mixing Valve
1-2 weeks delivery time The Isotemp 6P2531SPA0100 Spa 25L marine water heater features a 6.5-gallon stainless-steel inner tank, impact-resistant polypropylene casing and a 230V/750W immersion heater. Delivered without a safety valve and mixing valve, it provides a compact and cost-efficient heating solution for installations using external pressure and temperature-control components.
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$ 747.53
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Isotemp 6P3031SPA0100 - 230V/750W SPA 30L Stainless Steel Marine Heater without Safety, Mixing Valve
1-2 weeks delivery time The Isotemp 6P3031SPA0100 Spa 30L heater features an 8-gallon stainless-steel inner tank, polypropylene casing and a 230V/750W immersion heater. Delivered without a safety valve and mixing valve, it provides a durable, space-efficient and economical solution for installations using external pressure relief and temperature-control systems.
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$ 753.91
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Isotemp 6P4031SPA0100 - 230V/750W SPA 40L Stainless Steel Marine Heater without Safety, Mixing Valve
1-2 weeks delivery time The Isotemp 6P4031SPA0100 Spa 40L heater features an 11-gallon stainless-steel inner tank, polypropylene casing and a 230V/750W immersion heater. Delivered without a safety valve and mixing valve, it is intended for installations using external pressure relief and temperature-control systems, while maintaining compact 26" × 15.4" dimensions for marine spaces.
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$ 798.64
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Isotemp 6P5031SPA0100 - 230V/750W SPA 50L Stainless Steel Marine Heater without Safety, Mixing Valve
1-2 weeks delivery time The Isotemp 6P5031SPA0100 Spa 50L heater features a 13-gallon stainless-steel inner tank, polypropylene casing and a 230V/750W immersion heater. Delivered without a safety valve and mixing valve, it is designed for installations using external pressure relief and temperature-control components while maintaining a 29.3" length and 15.4" OD.
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$ 970.94
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Isotemp 6P6031SPA0100 - 230V/750W SPA 60L Stainless Steel Marine Heater without Safety, Mixing Valve
1-2 weeks delivery time The Isotemp 6P6031SPA0100 Spa 60L heater features a 16-gallon stainless-steel inner tank, a robust polypropylene casing and a 230V/750W immersion heater. Delivered without a safety valve and mixing valve, it is suitable for large onboard installations that use external pressure and temperature-control systems. Dimensions: 33.5" length, 15.4" OD.
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$ 988.41
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1-2 weeks delivery time The Isotherm SEA00041LA thermostat is a replacement control unit for Isotemp Basic and Slim-B marine water heaters. It provides stable temperature regulation and reliable switching to maintain consistent hot-water output, ensuring correct operation in onboard systems exposed to vibration, humidity, and fluctuating temperatures.
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$ 70.04
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1-2 weeks delivery time The Isotherm SEA00042LA is an overheat protection thermostat for Isotemp Slim-B and Basic marine water heaters. It provides safety shutdown in case of excessive temperature, protecting the heating element and system components. Designed for harsh onboard conditions, it ensures reliable thermal safety in hot-water installations.
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$ 56.03
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1-2 weeks delivery time The Isotemp SEE00019LA is a 230V/750W replacement heating element for Basic and Slim-04 marine water heaters. Supplied with a sealing gasket, it provides stable heat output and corrosion-resistant performance, restoring reliable hot-water operation in onboard systems.
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$ 84.05
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1-2 weeks delivery time The Isotemp SFD00003AB mixing valve kit is designed for Isotemp Basic and Slim-B water heaters from 2007 onward. It stabilizes outlet temperature, protects onboard plumbing, and ensures safe hot-water delivery using marine-grade, corrosion-resistant components.
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$ 150.59
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1-2 weeks delivery time The Raritan 1700 Series Boiler, with a capacity of 45.4 L, features horizontal mounting and operates as an electric unit with a heat exchanger. It boasts a glass-coated steel tank for high efficiency, a corrosion-resistant polymer casing, and polyurethane foam insulation to minimize heat loss. With a 5-year warranty, magnesium anode for protection against corrosion, and an adjustable thermostat ranging from 45°C to 80°C, it also includes a 75 PSI pressure relief valve and convenient side hose connections for easy installation.
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$ 3,068.97
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How does a marine water heater differ from a standard household water heater in terms of design and function?
Marine water heaters are specifically designed for use on boats and yachts, differing from household water heaters in several ways. They often incorporate stainless steel inner tanks to resist corrosion from saltwater, and they utilize both engine heat through a heat exchanger and electric power (120V or 240V) for heating. These compact units, like the 6-gallon and 10-gallon models, are built to handle the harsh marine environment and limited space onboard.
How does the heat exchanger in a marine water heater work to heat water efficiently?
A marine water heater with a heat exchanger efficiently heats water by utilizing engine coolant or another heat source that passes through a coil inside the tank. This process transfers the heat from the engine to the water, providing consistent hot water on board without relying solely on electric heating elements. The front heat exchanger design found in many models allows for faster and more efficient water heating.
How does the pressure relief valve ensure safety in a marine hot water heater system?
The pressure relief valve in a marine hot water heater ensures safety by releasing excess pressure if the water inside the tank overheats or exceeds the set pressure limits. This prevents potential damage to the heater and plumbing system, avoiding leaks or ruptures. In marine environments, where space is limited, this safety feature is crucial for maintaining safe operation of the water heater under variable conditions.