My Off-Grid Water Heating Solution

Off grid water heating solution & bbq

For a long time, I’ve been using my work van as a stealth camper. The two purposes of the van have lead to some creative, mostly serendipitous, solutions to the off-grid hybrid working/camping van. This latest feature to be added is how I heat my water in the van to allow for showering.

I particularly like the way this method has formed as it allows both heating as required and/or using waste heat from cooking or if having a campfire.

What I have ended up using, is a heat exchanger from an old boiler. This method is easier (no installation), actually more functional because of the way it can be heated up ie with a camping stove or with a fire inside or both! And It was also free! ;-). I have access to a lot of scrap so was able to assemble from parts.

Test Results, Analysis & Overview 😀

Test 1 – 60 liters of water with a camp stove* a little over 1 hour to heat to 40 degrees. *Coleman dual fuel camp stove which can run off petrol. start off temp 15/16 degrees. The link takes you to eBay

Test 2 – 60* liters of water with bbq charcoal. Approx an hour and a half to 42.5 * I brimmed the tank this time, so there may have been a bit extra in there. start off temp 15/16 degrees

Test 3 – 60 liters of water with bbq charcoal again. This time concentrating on the test. Actually only took 58 mins from 14degrees to 40. I have a leak which I’ve not fixed yet. Instead, I caught the water in a pan and heated up on top of the exchanger and then added back in. I am going to do this again.

Being able to heat on demand and/or whilst you’re cooking is an absolute result for me. With a properly insulated tank, the heat from the evening’s bbq can be used and then a potential quick blast in the morning with the camp stove to get back to the required temp. For more details about the portable shower system I use I will write up another post.

Is it safe?

Theoretically, and only in my opinion – yes. However, do your own research and testing. Cooper has a high melting point, just over a 1000 degrees C. Its coated in very high temp paint and water is being circulated round it constantly. In context probably safer than a camp fire or bbq.

Cooking and heating water off grid
Dual Purpose heating the water as i cook!

Another useful item to have in the work van/camper van arsenal are firelighters. But you don’t want smelly chemical ones though! you want upcycled waste ones, like the ones made by our friends at, specialists in house clearance and upcycling.

So I went through many iterations of water heating and a fair bit of money if truth be told. Here is a list of what I tried and what I wanted to try.

  • Portable Horse Shower – takes you to eBay. This was a fantastic piece of kit and would have been really useful for my work. However, I have a small van and would have required a gas cylinder too. Also, make sure you tighten all the gas fittings! :-{
  • Electric Underfloor Heating eBay – This wasn’t for heating water but thought I would add to the list. Yes, I did this! With unexpected results. (not recommended). I would do this again in my next van but for a different reason. Rather than trying to use it as a heat source, the wattage I chose was woefully inadequate. However, it was enough to dry the floor out in spots. As I use the van for work it can get wet. Saying this I would probably do a better job of fitting the floor, so technically it would not matter as much.

We will be happy to hear your thoughts

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