✅ How to Ensure Hot Water While Motorhoming?
Motorhoming – or simply traveling with a motorhome – is synonymous with freedom, independence, and a connection to nature. However, to fully enjoy comfort on the road, a functional and well-planned water supply is essential. The water system in a motorhome – though smaller and simpler than in a house – requires knowledge, care, and regular maintenance. Below, you’ll find the most important information you should know when planning the water supply in your motorhome. It turns out that the makeshift heating of hot water in a motorhome is not as problematic as one might think.
Motorhomes are equipped with special freshwater tanks that can be filled at service stations, campsites, or via a garden hose from a home water supply. However, the quality of the sourced water can vary, which is why more and more people use pre-filters to trap larger impurities. Motorhoming isn’t for everyone, and one of the hurdles is the limited comfort – particularly regarding access to unlimited water. The source of the water plays a big role – it’s not always of high quality, and groundwater (e.g., from a spring) is often hard, which determines the equipment we use to treat it.
We can also enjoy this while motorhoming, though, of course, you’ll have to forgo long showers like at home. There are methods for heating water in motorhomes that utilize heat from the engine, auxiliary heater, or Webasto systems, but more on that later.
The basic device is an electric heating element with appropriate power, though its drawback is that you need to be near a 230V power source.
Another solution is gas or gas-electric water heaters. They offer independence from electricity when running on gas – or from gas if they have a built-in heating element. Their downside is their size; it’s another sizable device that you have to carry, which can become cumbersome on long trips.
Another option is a water heat exchanger for motorhomes and its integration into the motorhome’s system. A heat exchanger connected to the heating circuit (e.g., to the auxiliary heater, engine, or Webasto system) is a highly energy-efficient solution – because the heat energy generated by the engine would otherwise go unused. While driving or when the heater is running, the heat is transferred via a plate heat exchanger to the water tank, providing hot water without additional fuel consumption. It’s a very compact device that doesn’t add significant weight, and its cost isn’t excessively high.
✅ Heat exchangers should primarily be chosen so that they’re not too small. Experience shows that models with a plate area of less than 0.5 m² are unsuitable because heat recovery would be too weak and water heating too slow. This doesn’t provide enough comfort. Choosing an oversized heat exchanger doesn’t cause problems, aside from being slightly more expensive and heavier.
✅ Heat exchangers for motorhomes should have a minimum plate area of 0.6 m² (often referred to as heat transfer area), optimally around 1 m² (if maximum comfort is desired). In practice, the price difference between them isn’t very large – and it’s enough to know that the total plate area is crucial for making the right choice.
✅ Regarding connection sizes – overly large connections usually aren’t necessary. Such a water system doesn’t have extremely high flow rates, and in most cases, 3/4" connections are entirely sufficient.
Some motorhoming enthusiasts see this as a drawback, while others enjoy small tasks upon arriving at their destination. A plate heat exchanger that has been operating for several days or weeks with water of not always known quality should be cleaned to ensure healthy, bacteria-free water. If no special cleaning agents are available, gently flushing it with citric acid (available in almost any grocery store) will suffice. This usually takes just a few minutes – prolonged cleaning isn’t advisable, as the acid could eventually react with the heat exchanger’s solder materials.
We’ve dedicated a separate article to flushing the heat exchanger in a motorhome – we invite you to read it if you’re interested.
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