• The adaptors are 3D printed, won’t they melt?

Conventional 3D printed materials would not be able to withstand the heat from a diesel heater, however we use engineering grade Polycarbonate which is incredibly tough and heat resistant.

  • Will my van get hot?

The vast majority of the heat from the diesel heater is transferred to the water meaning that the resultant air is far cooler than normal. However if you are worried about your van getting hot, then we sell a diverter valve to prevent this. It allows you to duct the hot air directly to the water, and then out of your van whilst our kit is in use. Then you can switch it back so that you can use your diesel heater for it's original keep you warm! If you can't access the diverter easily, then you can always purchase a remote cable to change the valve from a distance. 

  • Does the tank need to be next to the diesel heater?

No, the tank can be as far away as you want it to be, just purchase extra lengths of silicone tube from our online shop. The heat exchangers can be placed wherever is convenient in your van, as long as they connect to the diesel heater ducting.

  • Can I add extra heat exchangers?

If you like you can add an extra heat exchanger to improve the efficiency of your system from our website, but it is the law of diminishing returns. If you purchased a smaller system then it is worth doing, but if you have purchased a bumper system then the performance gains from additional heat exchangers are minimal.

  • What is the maximum temperature my water can be heated to?

The water can be heated to 70 degrees, this is the maximum that the water tank can withstand.

  • Does the Bobil system control the diesel heater?

The controllers work independently of the heater, detecting when the heater is on to turn the pump on, and switching the pump off when the water gets to the set temperature. There are ways of hacking your heater to allow it to be switched off when the water is at the correct temperature but we would not recommend this as it involves soldering wires to the off button on the controller and wiring them through the second relay instead of the pump. Try this entirely at your own risk!

  • Does it affect the air flow and will it damage my heater?

The air flow change is minimal and it does not damage your heater. We tested this by measuring air speed at the outlet of the heater, then added a length of ducting, then added each of our three heater options to the ducting and measured the airspeed at the outlet of each of them. In our tests, simply adding a 20cm piece of ducting made a much bigger difference to the flow rate than our heat exchangers. A long ducting run would have a much greater effect on the airflow than adding the Bobil system.

  • How do I see the level of the water if the tank is insulated?

We sell a level indicator which allows you to run a clear pipe to the outside of your insulation, meaning you can always see the water level.

  • How do I get water into and out of the tank?

Please see our downloadable guide available here.

  • Is your system pressurised? 

No, pressurising this system is unsafe, please do not try it. All our tanks are vented.

  • Why don’t you use the wasted heat from the exhaust? 

See our youtube video where we tried exactly this!

  • Will this system give me legionnaires disease?

Not if you use it properly. Legionnaires disease happens when stagnant water is kept warm for a long period of time. We suggest that you either fill the tank, heat it and use it immediately, or heat it to over 60 so that the bacteria is killed. As a precaution we do not recommend that you keep the water at 40 for long periods of time.

  • Can I use this with a Propex gas system?

Yes, it will work with any system which uses 60mm or 75mm ducting, although your heating times may vary. 60mm ducting connects to our 2kW heater systems, 75mm fits to our 5kW heater system.

  • Can I use this with a calorifier?

Yes, assuming you have a twin coil calorifier you can purchase the system without a tank. We would recommend turning your heater down as running your heater on full will not translate to fast heat transfer to the water. See our youtube video where we built a calorifier and tested it!

  • Can I use a Wallis XC Duo with this system?

No, unfortunately the ducting isn’t compatible with this product.

  • Do you ship to my country?

Yes we do ship internationally. Please see our shipping costs here.

Now you've had all your questions answered, all you need to do is pick your perfect water heating solution!

60mm ducting

Check out the options for your 60mm ducting


diesel heater water heater

75mm ducting

Here are the options for your 75mm ducting


diesel heater water heater