What type of hot water heater will you need for your caravan / RV?
What are the advantages of hot water heaters and do they operate on gas and
Are all hot water heaters the same?
caravans, campervans or RVs come with a hot water system/hot
water heater. If the caravan, travel trailer, campervan or
RV does not have a hot water heater then you need to boil
the jug (electricity) or kettle (gas) for washing up and
are two main types of hot water heaters ie: storage and
continuous or tankless. Storage hot water systems hold hot
water in a tank where continuous (or instant/tankless)
systems heat the water as it passes through a heater. The
hot water heater storage tanks are available in various
RV’s have the storage type hot water heater. These storage
type hot water heaters operate on mains power or LPG gas.
If operating on gas, you must remove the gas cover or cowl
located on the outside of some of the earlier model RV’s
prior to switching the gas unit switch on.
larger motorhomes, including the coach style, have a diesel
/ electric hot water system.
Suburban, and Atwood are some of the major players in the
supply of hot water heaters for RVs.
RV Tankless Hot Water Heaters
are various makes and models of tankless hot water systems
for RV’s and they can be powered by mains electricity or
For example there is the Stiebelt Electron DHC Instant
Tankless Electric Water Heater or the RV500 Tankless LPG
Any gas water heaters should be installed by a licensed gas
installer and comply with National Gas Standards. Any
continuous gas hot water service must be externally vented
(draws air in from the outside and exhaust to the outside of
Instant Hot Water Heaters
For those of you without a RV hot water storage system one
solution is to replace your sink tap/faucet with a RV
Instant Hot Water appliance and connect it to mains
power point in your RV. It can be hard wired into the RV
but installation should be done by a licensed electrician.
Your RV must have a 15 amp circuit.
ceramic device and tap provides instant hot (and cold)
running water to your caravan, trailer, RV or motorhome.
The manufacturer states it runs on normal mains pressure
and delivers water in the temperature range of Cold – 50
degree C. For mains
pressure and pump water you will need a no return valve on
each line and the pump will need to operate at a rate of
more than 4 litres per minute.
The RV Hot Water device operates on mains power but does not
operate on 12V. The manufacturer states the current draw is
11.2 amps – 13.2 amps. The product can be run by a
generator but it will require a 2.5 kW or a 3000 watt
Another instant hot water heater is a Rezi
Electric Water Heater. The Rezi hot water
heater with the heating element power of 3.3 kW is
recommended for caravan, travel trailers and
motorhomes. Rezi’s website states that the lifespan
of the unit, provided instructions and
recommendations of the manufacturer are met, is 8
Storage Water Heaters for RVs
RV storage water heater tanks are designed to withstand
water pressures of about 45 psi so if you are using city or
town mains water you may wish to use a water pressure
limiter to protect the storage tank. Maintenance of RV
storage water heater tanks should be carried out as per the
RV water heaters with storage tanks may be run or powered by
LPG (liquefied petroleum gas) or 230/240 mains electricity
whilst others can have the option to operate on either LPG
Truma storage water heater operates on LPG or 230/240V mains
power. Truma state their water heater storage tank is made
from high quality food-proof stainless steel VA. For
maintenance they recommend using wine vinegar for de-scaling
the water heater by introducing it into the appliance via
the water supply. Allow the wine vinegar to react and then
thoroughly flush out the appliance with plenty of fresh
water. To sterilise the water, Truma recommend
‘Certisil-Argento’ and state other products, particularly
those containing chlorine are unsuitable. To avoid the
colonization of micro-organisms, heat up the Truma Boiler to
70 degrees C at regular intervals.
Truma recommend you do not use the hot storage water as
For those of you who live in colder climates where you
experience frost or freezing temperatures and your RV or
mobile home is not used during this time Truma state it is
essential that the boiler hot water heater be emptied.
Suburban Water Heaters
storage water heaters are available in various holding
capacities and combination gas/electric models are also
available. Heated water attacks metals but not porcelain so
Suburban uses porcelain lined steel water tank with an anode
rod to ‘absorb’ the electrolytic action.
Suburban also have certain model water heaters available for
motorhomes with a motor aid heat exchange that utilises heat
from the motorhome’s engine to help heat water during
Duoetto Hot Water Heaters
Duoetto manufacture a 5 litre (1 gallon) and 10 litre (2
gallon) electric water heaters. The Duoetto 10 litre (2
gallons) mini electric water heater is ideal for an RV
shower. The tank is made from high quality food grade 304
stainless steel and its size is 430mm x 220mm x 230mm
(roughly 16”x 8”x 9”). The Duoetto features a variable
thermostat 30-75 degree C on 240 V. Power consumption of
the Duoetto hot water heater is 12V -25 amps and 240V - 4.5
amps and the unit comes with automatic voltage detection for
switching from 12V to 240 volt.
These units are available through AusJ Imports and Camec.
Rods for RV water heaters
A sacrificial anode rod protects the hot water heater
holding tank from corrosion by attracting corrosive elements
in the water so they attack the rod instead of the tank.
Anode rods are used in Suburban and some Atwood storage
water heater tanks and they should be checked
after each big trip or about every 6
months. Suburban recommend replacement of the anode rod
when consumption or weight loss of the rod is greater than
75%. To remove the Suburban anode rod you will need an
For instructions on how to replace a
sacrificial anode refer
Information obtained from a USA supplier
which was posted on a forum states ‘Galvanic
(sacrificial) anodes for cathodic protection falls under
Australian Standards (AS) 2239 -2003. Under the AS
2239-2003 there is 3 anode groups – zinc alloy anodes used
in marine applications and as earthing anodes, aluminum
alloy anodes mainly used in clean seawater and general
marine use with the exception of a special chemistry for use
in potable (drinking water) and magnesium alloy anodes
generally used in freshwater (drinking water).
The Aluminium anode for use in drinking water
is made from high purity Aluminum and alloyed to a specific
chemistry, usually produced in extruded rod form in a
diameter of 17 mm , fitted with threaded steel plug.
The Australian manufactured Aluminum anodes
have the top of the steel plug colour coded blue for ease of
This anode application is mainly used in areas of "hard
"water, high in total dissolved
solids, where the TDS is in the range of
The Magnesium alloy anodes that are used for
the protection of hotwater systems are produced in two
There application for drinking water is as
1. M1 used in areas of high purity drinking
water ie Alpine.TDS levels 0-40 mg/Litre
The Australian manufactured assy is usually
21 mm dia rod. The top of the steel plug is colour code
Green for identification.
Note very few of the M1 type is sold or used
for general hotwater systems
2. M2 the main anode chemistry for use in
For use where the TDS levels are 40-600 mg/Litre.
The Australian manufactured assy is usually
21 mm dia (can be 26 mm dia for larger domestic and
industrial systems) The top of the steel plug is colour
coded Black or Orange’.
We are informed that all Suburban water
heaters come from the factory with a magnesium anode rod.
It is suggested you use an aluminum rod if
you come from an area with poor water quality as the
aluminum rods do not degrade as fast.
The use of any water softener will also degrade the
magnesium anode rod quicker.
Regular flushing of the hot water tank (and
even the fresh water tank) to remove any build up of ‘gunk’
should help the life of an anode rod and eliminate any bad
Some people we know purchase the anode rods
through an online store in the USA called rvingoutpost.com.
Anode rods are
available from RV accessory stores and eBay.