Everything You Need to Know About Motorhome Water Heating

Not all caravans, campervans, or RVs are made equal. Only some models come with a hot water system. If your motorhome does not have a hot water heater, then you will need to deal with the hassle of using an electric jug or an old-fashioned kettle for washing up and showering.

There are a lot of options when choosing hot water heater storage tanks because they are available in various sizes. Hot water heaters can either be storage and continuous or tankless systems. Storage hot water systems hold hot water in a tank where continuous (or tankless) systems heat the water as it passes through a heater.

The most common way of storing hot water in RVs is by the storage system. These heat water by means of electricity or LPG gas. On the other hand, larger motorhomes like the coach style have a diesel/electric hot water system. Trauma, Suburban, and Atwood are some of the major brands that supply hot water heaters for RVs.

What Are the Benefits of Having Continuous or Tankless Water Heaters?

Tankless Water Heating For Trailers

As mentioned earlier, there are various brands and models of tankless hot water systems for RVs and they can be powered through electricity or gas. Standard storage tanks hold either 23 or 38 litres of water.

That amount of water may be enough for one to three persons, but a family or group of 4 might find it lacking. A normal 38-litre storage heater also takes about an hour to heat up compared to the instant heating of tankless water heaters. Hence, they are named continuous because you will never run out of water.

Another benefit is that you don’t run out of LPG or propane as quickly as when you’re using storage heaters. This is because storage heaters maintain the water temperature for a longer time while tankless heaters do this on-demand (whenever you turn on the faucet). You would also have a constant flow of hot water by merely turning the faucet on.

As the water begins to flow, the sensor tells the burner to increase the water’s temperature. This makes tankless water heaters more energy efficient and “greener”. Aside from helping to save the environment, you can also save a lot of money by using them. Since there’s no need to store water, the storage tank is also not needed. This is the main benefit of going with tankless heaters because you can save a lot of weight in your motorhome.

If you opt to use a tankless heater that use gas, it should be installed by a licensed gas installer and comply with National Gas Standards. Any continuous gas hot water service must also be externally vented.

What Is an RV Instant Hot Water Heater?

Rezi Electric Water Heater

The RV Instant Hot Water connects to the power outlet in your RV. This can be a viable solution for those of you that don’t have a built-in water heating system. It can also be wired directly into the RV, but it should be installed by a licenced electrician. Your RV must also have a 15-amp circuit.

The ceramic-built device and tap provides instant hot (and) cold water to your motorhome. The manufacturer states that it runs on normal mains pressure and delivers water in the maximum of 50oC. For mains pressure and pump water, however, you will need a no-return valve on each line. The pump must also operate at a rate of more than 4 litres per minute.

The RV Instant 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 3 kW inverter.

Another instant hot water heater model is the Rezi Electric Water Heater. This water heater has a heating element power of 3.3 kW and it is suited for use in caravans, camper trailers, and motorhomes. The brand’s website also states that the unit has a lifespan of 8 years, provided that their instructions and recommendations are followed.

What Is An RV Storage Water Heater?

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 manufacturer’s instructions.

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 or electricity.

What Brands of Water Heater Should I Buy? How Do I Maintain It?

Based on my experience and from what I’ve heard from other peers, there are three brands that make the best RV water heaters in Australia. These are Truma, Suburban, and Duoetto. I can recommend these brands’ water heaters because:

  • Truma Boiler: this has a storage tank and operates on LPG or electric power. The water storage tank made by Truma is made from high quality and food-proof stainless-steel VA. For maintenance, they recommend using wine vinegar for de-scaling the water heater. First, you will need to introduce it into the appliance via the water supply. Then, you should allow the wine vinegar to react and then thoroughly flush out the appliance with plenty of fresh water.To sterilise the water, Truma recommends ‘Certisil-Argento’. Using other products is not suitable because these might contain chlorine. Heating up the tank to 70oC regularly can stop the formation of colonies by microorganisms. For those of you who live in colder climates where you experience frost or freezing temperatures, it is essential that the boiler hot water heater be emptied when not in use.
  • Suburban Water Heaters: their water heaters come in various holding capacities and gas or electric models are also available. Suburban’s water heaters are made of porcelain-lined steel which is more effective than those made of metal (because heated water attacks them). Its water heaters also come 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 operation.
  • Duoetto Hot Water Heaters: Duoetto manufactures 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 which can go from 30-75oC on 240 V.The 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 240V. These units are available through AusJ Imports and Camec.
  • Webasto: they have a diesel-powered DualTop compact unit which combines domestic hot water with interior cabin heating for motorhomes. The brand also makes heaters with a heating power ranging from 0.2 kW-9.2 kW, depending on the model. Their heating system is fuelled directly from the vehicle’s fuel tank. The RHA 102 & 103 models feature digital control.The DualTop hot water heater and interior heating unit can be installed underfloor thereby freeing up internal space within the motorhome.
  • Eberspacher: this brand has produced a diesel-powered water heating system for the motorhome market. Like the Webasto heaters, this can be installed underfloor or in the engine compartment.Hydronic D4W System provides a heating system with an automatic sensing and temperature control for the vehicle’s interior while also storing sufficient hot water. The heating system is diesel-powered and is taken directly from the vehicle’s fuel tank. The 10-litre hot water storage tank features a thermostatic mixer valve that automatically blends hot and cold water thereby increasing the amount of available hot water.
  • Oasis Modular Heating System: is tailored for the Class A motorhome or luxury coach. It is a diesel-powered “hydronic system” which has two components, the heating component and the Oasis Distribution Model.The second component comprises an engine interface heat exchanger, a domestic water heat exchanger with an anti-scald valve. The valve also comes with circulation pumps and a winter/summer solenoid. The brand also produces two models, the CH35 and CH50. These models have 35,000 BTU and 50,000/BTU/ph, respectively.

Related Questions

Are Anode Rods for RV Water Heaters Any Good?

Anode rods protect the hot water heater tank from corrosion by attracting corrosive elements from the water by causing them to attack the rod instead of the tank. Anode rods are used in some brands like Suburban and Atwood storage water heater tank.

The rods need to be checked after each big trip or about every six months if you use it sparingly. In contrast, Suburban recommends the replacement of the rods when it reaches a weight loss greater than 75%.

How Do I Replace an Anode Ray?

The information written below was 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 aluminum 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 identification. This anode application is mainly used in areas of “hard “water, high in total dissolved solids, where the TDS is in the range of 600-2500 mg/litre.

The Magnesium alloy anodes that are used for the protection of hot water systems are produced in two specifications. The application for drinking water is as follows:

  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 hot water systems
  2. M2 the main anode chemistry for use in hot water systems. 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 that 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 buildup of gunk. This can extend the life of an anode rod and eliminate any bad smells. Additionally, some people we know purchase the anode rods through an online store in the USA called rvingoutpost.com. Anode rods are also available from RV accessory stores and eBay.

Can I Do Gas-free Cooking on Motorhomes?

Yes. With the introduction of the Webasto Diesel Cooker X100, you won’t need to rely on LPG gas for cooking. It is powered by diesel and it is integrated into the cooker which heats a Ceran® glass top cooking surface which is suitable for two small saucepans.

The exhaust is also vented to the outside of the motorhome. Webasto has stated that it has a low current and fuel consumption with high cooking power of up to 1800 watts.

Wallas also produces diesel-fuelled ceramic cooktops mainly for marine application. However, some RV owners have adopted their use and installed them in motorhomes. The fuel for these diesel operated cooktops can be taken from the motorhome’s diesel tank.

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James Mitchell

Hi, I’m Jimmy Mitchell and I love exploring this great country with my wife and two boys. I have a 2015 Sterling LX that is the Mitchell Family camping machine. Lets Getaway is the website where I share things about my trailer as I learn them, and help other camper owners to enjoy their RV even more.

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