Last Updated: 07/09/2023
Picture above is the Australian made Genesis 11
The Hot water System for RV is probably the most used, advertised, confusing and possibly expensive item that will make it into your RV. So, it really pays to get it right the first time!
As I previously mentioned in the Log I have no LPG installation in mind for my vehicle, but if you do, then your choice is very easy:
- A Domestic LPG/NG Hot water System
- An RV LPG/NG and Electric Hot water System
My suggestion would be to go for the domestic type, that beside having spare parts and technical support at practically any plumbing supply store, it also, in my opinion, offer a better value for money out of your burnt Gas. Only downside is that you can’t however have both Gas and electrical in a Domestic Heating System.
If you are thinking to take this path, you could look at the Bosch External Hydro Power 16H.
The thing I always liked about the Bosch Hydro Power is that it required no standing pilot light or power point to operate. That makes it safer easier and cheaper (LPG) to run from the rest… However, using this system in an RV could make you run in to trouble as it need a good constant flow of water for the ignition and gas to constantly flow. In the manual it states that it need a minimum of 3.2-4 l/min. Your shower head should be rated at 9 l/min, so in theory it should be fine. In reality, it could happen that because you also have cold water in the mix, the hot water pipe may drop below the 3.2 l/min and shut off the unit. I’m not say this is what it will happen, but it could happen especially in the warmer months.
Finally, if this unit is used with bore water, the minerals that deposit inside the ignition box pipe, could again create ignitions problem. This of course can be fix with the installation of a good water filtration system that you should already have in your RV anyway. If all the above is cause of concern, then a standard Hot water system (the one’s requiring both Gas & Electricity to operate) may be a best solution.
There are plenty of brands to choose from: Bosch, Rinnai, Rheem, Thermann, Dux, Merlin…. They all operate and look very similar, so price, availability and size, may be the deciding factor in choosing one…
If you feel the need to have both Gas and electrical, (240 Volts Main), then you must pick from the RV design:
- Airxcel famous and most popular Suburban SW6DEA
- Truma AquaGo (GAS only)
- Truma Ultra Rapid (available either in Gas or Gas +Electric)
The Suburban SW6DEA
To pick one out of this list, I would compare prices and availabilities of spares. The Suburban has been around for a while and it has developed a good network around Australia as most camping/RV shop seem to carry them…
Right. Now that the Gas is out of the equation, lets concentrate on the “other” hot water system… These hot water system run on the other common fuel, Diesel 1, Diesel 2 or Arctic Diesel, (same fuel but with different freezing characteristics). This makes it appealing to a lot of people as you don’t need to get a Gas installation and Certificate and in most cases, your RV has a huge Diesel fuel tank already installed.
These Hot water System do come in two distinct separate flavours: Water only or Water & Air Systems. There is not much difference in size between the two, so in the end it comes down to personal preferences, as in, do you want all your eggs in one basket? If you think about, you will probably need hot water every day, but you don’t need hot air in your RV every day, unless is winter or you are always in a cold climate. Diesel burner are pretty good and strong, but they do, (like most burners), required maintenance. The more they work, the more they need servicing…
With this in mind and based on my previous experience, I went for two separate system for water and air, but that’s just me. I’m sure that today’s system are pretty good…
I said above that they come in two distinct flavours, but I should also mention that the most expensive systems do run on Diesel, but they can be run on Main Power as well, if required or both simultaneously.
After doing a bit of Googling, it seems that most American expensive RV use the Oasis Heating System.
This is probably the “Ferrari” of the Hot Water System made by ITR and the beautiful thing is that it comes boxed and ready to install. The brochure state is 116 kg full and 90 × 48 × 38 cm in size. It has a 3000W (2 × 1500W) heating elements and a 52 litre coolant tank. Coolant tank? Yes that’s correct. Hidden in the box is a tank containing the same coolant used by your engine. As a matter of fact, this box does contain two parts: the Diesel Burner and the exchange tank (a.k.a. Calorifier or Hydronic). Actually the Calorifier works in the opposite way as it use a small amount of coolant to heat up a large amount of water (like an instant Gas system), where in this system a large amount of coolant is used to heat up a smaller amount of water as it pass through the system. The end result is however the same…
Now the bad part of this system is that, for start is nearly a 1 metre long and therefore unless you have that specific space, it won’t fit. Then, being a US/Canada product you may find it a bit hard to get technical/parts on this side of the world.
Finally, there is the price… Once converted in AUD, you are looking around the $6.300.00 dollars. Maybe this is the reason why you won’t find many websites actually advertising the Retail price 😮 …
If you look at the feature picture of this article, you can see that I used the Australian kind of version of the Oasis.
Ok the Genesis 11 is not the same in features, but it does a similar job. It has the burner (much smaller) sitting on the side and it has a large tank for the coolant. It doesn’t have the heating element but it has two extra outlet if you with to use the system to heat up the air inside the vehicle. What I like about this system is that has a much smaller footprint than the Oasis and you can actually install the burner in a different location from the tank if you wish, then all you need is just to use longer hoses to get to the tank. For Australians RV selling at $1,880.00 dollars (or at 1/3 of the Oasis price), it does make a lot of sense.
As you can see in the picture, the Genesis gives you a preview of the components involved in making a hot water Diesel system: the Burner and the exchange tank. On the front of the tank, you can also see the temperature controller, where you can adjust the temperature by pre mixing the hot/cold water coming out of the top tee. You can also see the two extra plug where you can connect the two pipe that can carry the hot water to the radiators inside the vehicle. The burner is a 5Kw and even if they don’t mention how big the tank is, you can get an idea by the overall dimension that are 450x 350×310 mm. The tank seems a bit on the small size and that’s probably why they recommend using their system with the Bricor Shower Head (2.36 L/min). Considering that most domestic showers are rated at 9 L/min, this may doesn’t seem much but you have to remember that water in an RV is a precious commodity…
If I didn’t build my own system, I would have probably gone for the Genesis 11 as it is a good value for money compare to the rest out there…
While searching on-line, I also did find another brand called Aqua-Hot. They make five different model/size including a Gas one. Prices and specs are similar to the Oasis, so I won’t bother to review these unit as well but you can check them out HERE
Having a background in plumbing and having the time to consider all the pros and cons, led me to decide to build my own system using specific components that have already been tried and tested. I didn’t want to spend $6000+ dollars and I also didn’t want to have a shower using 2.3l/min ;-)… So I went for somewhere in the middle, something with specs closer to the Oasis but with a price closer to the Genesis 11.
My system feature a 9.1Kw burner and a 65 Litre true Calorifier (twin coil) tank and a 1.5kw heating element. I’m planning to do a review and installation pictorial of my system once Gigi reach stage 5…
Leave A Comment