Review
of the best boat water heaters
Atwood, Webasto, IsoTemp, Torrid,
Superstor
Marine water heater is the electrical or propane powered appliances
that is
used in the boating
industry
for space and hot water heating where the shower, washing-up and
personal
hygiene are the main applications.
These boat appliances provide an instant and sufficient
amount
of hot water using electricity or propane gas. Great advantage
also comes from
using the engine's wasted heat energy which means that the heating unit works with no running cost.
Marine hot water heaters are designed small and lightweight and for
restricted areas. These
great performing and
economical
appliances work in the harsh and very humid environment,
subjected to the fresh and salt
aggressive water action. This is the reason why they have to be
built with
high quality materials.
How does marine water heater work and what are the features?
Most of the manufacturers are designing water heaters for boats and
yachts with a
corrosion
resistant
casing like stainless steel or aluminum and stainless
steel
or metal storage tanks (with protection) from 6
gallons as the most common size, up to 20-gallon tank.
To get maximum from the heating element, immersion heaters are usually
positioned in the lowest part of
the tank where the water is coldest and in order to heat all
the
water in
the tank. Special attention is also given to the water inlets and
outlets for a minimal mixing of cold water into the hot.
Heat source for hot water heating is provided either
from the engine cooling water, AC generator
power or
hooked to shore power. Most heating elements work on 110 V.
There are also propane hot
water heaters specially constructed for the marine environment, with no
electricity needed and dependent on the engine's performance. With
closed
combustion they are reliable units with an option
to mount them almost anywhere.
Difference between superior and lower quality marine hot water heaters
is in the selection of component parts, where high-quality models are
represented
by incoloy sheathed heating elements; while other are built
from
copper (subjected to failure if not fully immersed in water when
energized), heavy duty heat exchanger, usage time/recovery rate,
insulation...
Thermostat has to be factory calibrated and Coast Guard
approved (UL) for
spark ignition protection.
Top marine water heater manufacturers:
Atwood water heater
Torrid
Superstor
Isotemp
Webasto
Marine
Water Heater Manufacturers
Atwood marine water heater is reliable and efficient electric heating unit,
offering models equipped with high quality 1.4 kW and 1.5 kW incalloy
heating element. Heating element is designed to provide hot
water
quickly and withstand accidental operation when the tank is
empty,
usually fatal for copper heating elements.
Designed as lightweight heater, it has a casing made of
high-corrosion
resistant
aluminum so it can work in the corrosive marine environment. Only two
models EHM6 SST, 6 gallon tank size and EHM11 SST, 10.5 gallon
tank size
have casings built from stainless steel.
Specialized aluminum alloys are also used for tanks, providing
an extended tank life while reducing the total weight which is
important for boat construction.
Superior heat exchangers use double tube construction, which prevents
any possibility of engine coolant to contaminate the fresh water system
that is running through.
Atwood marine water heater models are electric, with a tank
size ranging from 4 to 20 gallon capacity and recovery rate of
7.21 gallon per hour.
Torrid marine water
heater provides 5-year warranty against tank failure,
backed-up with 2 protective elements against corrosion; heavy-duty
glass lining and oversized magnesium anode rod. Torrid boat heaters
with
these two protective elements and safety thermostat cutoff are
constructed to last longer
and easily work in high temperature environment.
High density fiberglass insulation keeps the hot water longer
in the tank and increases your hot water usage.
Super efficient heat exchanger, made of high-quality copper with a
silicon bronze casting and 1.5 kW stainless steel sheathed
heating
element will provide great 15 gallons per hour recovery with 40 F rise.
Superstor marine
water heater is the high efficiency
unit consisted of
the high efficiency extended surface heat exchanger with
finned tube,
stainless steel corrosion resistant storage tank and 1.5
kW heating element for longer performance life and dock-side power use.
2-inch, CFC-free, water-blown foam insulation is environmentally
safe and used to protect the unit from energy waste and to reduce heat
loss.
You can choose models with 6, 12 and 20 gallon capacity and recovery
rate from 22 to 39 GPH with delivery of 155 F. All models are with
5-year warranty.
Isotemp hot marine
water heaters can be found in three different groups,
based on its shape and diameter; Basic
with 6.3 to 19.7 gallon tank
size and Slim
with 4,5 and 6 gallons capacity, both cylindrical in shape.
Either installed horizontally or
vertically great performance and fast hot water delivery is achieved in
both positions.
Slim Square
with 4.2 gallon tank size is another model from IsoTemp manufacturer
that provides an easy
installation in three different
positions, in narrow and limited space where Basic and Slim are not
viable solution.
High quality material like stainless steel is not used only for casing
but
for the tank, tubes, and all elements that are in direct contact with
water.
It uses heat from the engine coolant system and a standard 750
W
or 1.2 kW immersion heating element.
Isotemp Basic models 6403 D and 6753 D models have dual heat exchanger
for even better performance.
All models come with 5-year limited warranty.
Webasto
water heaters for boats and yachts, offers four
types of
marine heaters, for space and water heating.
for longer heater life and easier service...
Install unit per local codes
Install shut-off valve and drain valve
Locate the heater near a floor for easy draining
and
flushing
Protect unit from freezing temperatures
To connect heater use unions for plumbing
Always vent air from the heater
Tank must be full of water before power is turned on
Flush water from the tank every other month to get
rid of sediments