Raritan - Water Heaters

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Raritan - Water Heaters

World-renowned water heater specially designed for the marine environment. Provides the comfort and convenience of reliable hot water.

1700 Series Water Heater

* The tank is covered by a five-year Limited Warranty.
* Ignition-protected thermostat.
* Attractive polymer jacket resists corrosion from dampness.
* Glass-lined steel tank is more durable than stainless steel.


* Available in 6, 12 and 20 gallon models with or without engine heat exchangers.
* Available for 120V AC or 240V AC.


[email protected]

530 Orange Street
Millville, NJ 08332 USA

Phone: 856-825-4900
FAX: 856-825-4409

Website: http://www.raritaneng.com/

Water Heaters

additional info and manufacturers

Adding a water heater is neither a difficult nor an expensive operation and is well within the abilities of even the mechanically challenged. Few luxuries in boating are as pleasurable as a warm shower at the end of a long day at sea.

Unless you're the chief cook and bottle washer, that is, who uses hot water to scrub all the dishes at the end of a meal. Few other additions to the boat’s mechanical inventory will earn you the applause of your guests onboard as the installation of a marine water heater.

The only requirement is that the boat be fitted with a pressure fresh-water system with taps that will take hot and cold running water. If the boat is not equipped with a pressure-water system, one can be added at the same time as the hot water heater, vastly increasing the value and resale potential of the boat.

Connection & Location
when selecting a space

Since the electrical connection has no bearing on the location of the new water heater, the only limitations are due to the engine coolant hose runs and space inside the boat. Most engine fresh water pumps have limited capacity to move coolant long distances or to lift it very high. Consult the engine’s manual again as it may give specific instructions on the maximum length of run of hoses from the engine to the water heater and/or their maximum rise (head) above the engine block. Follow these instructions to the letter and remember: short runs are better than long ones.

You also have to work within the space around the engine. Any out-of-the-way location will work as long as the heater fits and the installation, and later maintenance, can be performed without the aid of a contortionist.

Remember when selecting a space for the new water heater that it must be firmly bolted in place. At eight-plus pounds per gallon, water is heavy. Having your water heater come loose in a seaway to bang around in the engine room would make for an unpleasant day at sea.

If the space you have chosen does not have a flat floor with access for bolts and nuts, you may have to install a shelf, bolted or fiberglassed in place, for the heater to sit on. Take this extra space into account when making your selection.

If installed athwartships, the heeling of a sailboat may alternately make the hot water flow downhill on one tack and uphill on the other. Many manufacturers note that installations on sailboats are best if the plumbing fittings are oriented fore and aft.


Marine water heaters have four main components: the tank, heat-producing coils, insulation and cover. Let’s look at them as separate pieces.

Water heater tanks are usually made of mild steel, stainless steel or aluminum, although we have seen older units made of cast iron and bronze. All these materials have some advantages and disadvantages. Steel is generally easy to attach plumbing fittings to but can and will rust over time. Aluminum heats faster, is lighter in weight and will not rust. But it will corrode galvanically around steel or bronze plumbing fittings. Stainless steel is superior for all purposes but tends to cost a great deal more.

The heating coils, whether electric or engine coolant, can be made of nearly any metal, but copper is most common for the electric coils while steel is most common for the engine coolant coils. So far, no problems. But be careful of the combinations of metals between the coils and the tank.

A copper electric coil fastened directly to an aluminum tank is an invitation to rapid corrosion of the aluminum. Likewise, an aluminum engine coolant coil fastened to a steel tank will not last long. At the very least, a good gasket between two disparate metals is imperative.

When looking at a shiny stainless steel cover that the tank is also stainless. Most imported marine water heaters on the market today have a polished stainless sheet metal cover, but the tank itself is inexpensive aluminum. This combination will work well for years but do not use bronze plumbing fittings in an aluminum tank.

The cover is there to dress the tank up cosmetically, hold and protect the insulation, and provide a mounting method. Cover materials may again be painted steel, polished stainless steel or aluminum. Many newer European models do not have a metal cover at all but rather have a tough plastic coating applied directly to the insulation to protect it.

These may look a little strange to the North American eye at first, but generally have superior rust resistance and insulation properties.

The insulation is what keeps the water hot once it has been heated and keeps the engine room cool as well. On many inexpensive marine hot water heaters, the insulation is nothing more than a piece of household fiberglass stuffed in between the tank and the cover.

This is usually inadequate to keep the water hot for very long, especially in a cold-weather boating area. As noted above, the European style made for boating in the North Sea is far superior in this regard.


Almost all marine water heaters come standard with two methods of heating the water electric element and engine heat exchanger. You may opt to connect only one or both at your discretion depending on how you use your boat. If you use your boat often you may wish to connect both heating methods. If your boat stays firmly tied in its slip, however, you may opt for the electric connections only. For long-distance cruisers and boats who rarely tie up at a dock, the electric connections can be left unmade and the cooling system of the engine can be used to heat the water.

The electrical connection to the ship's 120-volt system is a standard three-wire variety but care must be taken to ground the case, shell or cover of the water heater. Some manufacturers such as Torrid offers Custom configuration including 240V, 480V, 3 or morte Phase. As a water heater draws a fair amount of electricity when it is working, you may need to install a new circuit breaker or subpanel with the proper size current-overload protection.

Consult the water heater’s manual for the recommended size of both the circuit breaker and wire that should be used to connect the new heater.

On the engine heat exchanger side, the installation usually consists of some heater hose and a handful of fittings.

But note that the life of the water heater will be reduced unless the engine is fresh-water cooled as salt water running through the heat exchanger coils will corrode them rapidly. In this case, make sure that spare exchanger coils are available for your water heater and carry a spare. In addition, check your engine manual for the location of ports on the engine block for tapping into the coolant supply.

For warming up after a cold day of fishing or rinsing the salt out of your hair after a day of snorkeling in the tropics, nothing can take the place of hot water coming from the tap. With a few hours of measuring and planning, a day of installation and a few hundred dollars, one of life’s simple pleasures can be made available to all hands. And choosing the right water heater will deliver this immense pleasure for years to come.

Size and Orientation

Marine water heaters come in sizes from as little as five gallons up to house-sized units.

As usual, the cost rises with the number of gallons, so the trick is to choose one small enough to fit the space and budget, and yet be big enough to avoid having the water go cold in the middle of the skipper’s shower. Some intrepid cruisers can get two showers, a sink full of dishes and a load of laundry out of five gallons of hot water, other people use that amount to brush their teeth. Analyze the needs of your crew carefully before making a purchase.

In addition, some water heaters are round and vertical, a few are cylindrical and horizontal, and many are rectangular, a few are exact cubes. If you can’t fit one type in the space available, try a different shape.

The Horizontal Water Heaters such as "Torrid" (available from 6 to 80 Gallon ) are designed for areas with little headroom on your vessel. These Tanks are rated to 300 PSI and 150 PSI working pressure. The Torrid Water Heaters are Designed specifically for the marine environment,come wiht with 5 year warranty and complete maintainable anode protection system.

photo: Torrid Marine Horizontal Water Heater (www.marinewaterheaters.com)

Note: that installations on sailboats are best if the plumbing fittings are oriented fore and aft. If installed athwartships, the heeling of a sailboat may alternately make the hot water flow downhill on one tack and uphill on the other.