Review of the Jompy Water Heater
by John Fenna

The Jompy is a simply amazing water heater designed and patented by D Osborne of Troon, Scotland.

Originally designed for use in developing countries where drinkable water, and fuel to feed the fires to boil it to kill bugs, are both in short supply, the Jompy Water Heater is a triumph of making something simple and effective to address a real problem.

Luckily for us, it also has real applications for simple convenience in a bushcrafting situation.

In essence, the Jompy is a simple heat-exchanging coil of blackened aluminium piping with an insulated handle made up from the inlet and outlet pipes, a central “hole” to allow the fire/stove to continue cooking your food, and “pot stand” strapping holding the coils together and helping protect them from the pot above while still allowing heat to flow around the pot.


You simply connect a water supply – from a jug of water, an hydration bladder, slow running tap etc, with a length of hose (ordinary garden hose fits well) and once the water is flowing, you take your pot off the heat, put the Jompy on the heat and place the pot back, on top of the Jompy. The water running through the coils quickly heats up and with a decent cooking fire going (or stove running well) you get water at almost boiling point pouring from the outlet, almost instantly. Up to one litre of almost boiling water per 45 seconds can be produced effortlessly!

In developing countries the use of a Jompy not only helps purify water by killing disease-causing bacteria etc, but also saves on the amount of fuel consumed for cooking and boiling water and provides hot water for hygiene and general cleaning etc.

For bushcrafters it means you have almost instant hot drinks etc when you want them without having to reorganise your fire and wait until a second billycan has boiled!

The standard Jompy is about the size of a badminton racquet some 29.5cm across the coils, with a 30cm long handle that ends in the inlet and outlet pipes, which add another 10cm, and it weighs approximately 600gms.

The temperature the water comes out at can be adjusted by varying the water flow, which can be achieved by raising the water container for greater flow, or by crimping the hose. I find a small C clamp useful for controlling the flow if I want lots of water; otherwise just crimp it with your fingers to reduce the flow. The heat from your fire will also affect the water temperature; with low fires, the water will need to circulate more slowly to heat up.
You can thus produce near-boiling water for a brew or a lesser heat for a refreshing shower, as you desire, and all the while your food can be cooking away without interruption.

If you are not cooking, you can place the Jompy straight onto, or over, the fire as long as it is stable and the plastic of the insulated handle portion is not too close to the flames.

Be sure to have water flowing in the Jompy when it is on the heat or you could melt the coils!

An interesting feature of the Jompy is that as soon as you take it from the heat, the coils are cool enough to touch – so the chances of you accidentally burning yourself (or others) while making a brew are greatly reduced!

Connecting the inflow pipe to the coil that first runs around the outside of the Jompy helps ensure greatest efficiency and safety, but the system still works well if you connect it up to the other pipe.

The Jompy can even use solar power to heat the water. Hang it up in bright hot sun and let it heat up – thought perhaps not in wet Wales!

As you can see, the Jompy is a simple and effective way of getting water heated, making it ideal for groups getting together for a spot of bushcrafting, or for use on a static camp like the Bushmoot, but some may find it a little bulky and heavy for lightweight trips …

SO a solo lightweight version is under development which measures only 14cm across with a 20cm handle!

I have had a play with the prototype and found it good (while not as effective or stable as the standard Jompy) and capable of getting water noticeably warm, though passing the same water a couple of times did soon bring it up to heat for a brew. Watch out for new developments here.

The Jompy Water Heaters are simple, effective, quick (to say the least), convenient, safe and robust, and my old water heater may soon be retired from bushcraft trips!

The standard Jompy costs around £39.00.

For more details visit
Tel 01292 318194

A simple cooking fire with trivet stand

Cold water in, near boiling water out.
the Jompy in action

Jompy water heaters
Small Jompy producing hot water

Large Jompy

Near boiling water out and cooking.

Without Jompy

Water supply
Very hot water produced



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