Your tank water carries stuff a filter can't stop. UV-C does.
This is the plain-English guide to UV-C water sterilisers for caravans — what they actually do, how UV-C LED works, what specs matter, and how to fit one to your van. If you're comparing units and don't want to wade through marketing copy, start here.
What a UV-C water steriliser actually does
UV-C is a short-wavelength ultraviolet light. It doesn't filter anything. It doesn't add anything to your water. It shines through the water and wrecks the DNA of anything living in it — bacteria, viruses, Giardia, Cryptosporidium.
An organism whose DNA is wrecked can't reproduce. Can't reproduce means can't make you sick.
That's the whole trick. No chemicals. No taste change. No holding tank. Water goes in. Water comes out. Between those two points, the bugs are done.
Why filters alone aren't enough
Filters catch things that are too big to fit through them. Sediment, chlorine, rust, taste — all handled. Our own Pro Flow 12 filters down to 0.5 micron, which is very good.
But most bacteria are smaller than 0.5 micron. Viruses are smaller again — 0.02 to 0.3 micron. They walk straight through a 0.5-micron filter without breaking stride.
Then there's biofilm. Your fresh water tank sits in the heat. Slime grows on the inside walls. Even if your filter caught everything at the inlet, the tank itself becomes a bacteria factory. Every glass poured after that runs past the biofilm on its way to the tap.
Filter alone? You're catching sediment while missing the bugs. UV-C solves that.
How UV-C LED works — the 30-second version
UV-C sits between 200 and 280 nanometres on the light spectrum. The sweet spot for killing bugs is around 254–265 nm. That's the wavelength that damages the genetic material of anything living in the water.
An LED UV-C steriliser fires that wavelength directly into a chamber the water flows through. Contact happens in fractions of a second. The unit doesn't need to hold water. It doesn't need to warm up. It doesn't add anything.
Water in. Light on. Bugs done. Water out.
UV-C LED vs mercury lamp — why LED wins in a van
Most UV sterilisers in the world still use low-pressure mercury vapour lamps. They work at home. They're a bad fit for a caravan.
Five reasons LED wins in a van:
- Instant on. Full germicidal output in under a second. A mercury lamp takes 30–60 seconds to warm up. That's 30–60 seconds of untreated water going through your tap every time you flick the pump.
- No mercury. A glass tube full of mercury vapour rattling around on corrugations is not what you want under your sink.
- Low draw. LEDs run on DC. No inverter, no 240V step-up. Just wire it into the caravan loom you already have.
- Longer life. UV-C LEDs run for many thousands of operating hours. No lamps to swap out. Fewer consumables. Less to break.
- Compact. No lamp housing means the whole unit fits in tight installs — under-sink, in a cupboard, wherever you've got 20cm of hose run.
The short version: mercury lamps were designed for houses that don't move. LEDs were designed for everything else.
The 6 specs that actually matter
There are a lot of UV-C units on the market and most product pages hide the same specs behind different words. When you're comparing, look for these six:
1. UV-C LED, not mercury lamp. Non-negotiable for a caravan. If the seller doesn't say LED, assume it's a mercury unit.
2. Runs on 12V or 24V. Most caravans run 12V, but a lot of larger rigs, some motorhomes and off-grid setups run 24V. A unit that handles both without an inverter is the flexible choice. Ours is 24V native with a built-in booster for 12V systems — wire it into either. If a unit only takes 240V, it's built for houses.
3. Flow rate matched to your use. A caravan tap runs at 6–8 litres per minute at most. A unit rated to 8 LPM is plenty. Bigger units cost more and draw more power for zero benefit.
4. Standard fittings. 12mm push-fit is the caravan standard. If the unit needs custom adapters or threaded fittings you don't have, factor that into the cost.
5. Sealed housing. Caravans vibrate. Water splashes. Anything sitting under the sink needs sealed connections and a housing that survives moisture. O-ring seals, not glued joints.
6. Replacement parts available in Australia. A cheap unit imported through eBay with no local support becomes a paperweight when something fails. Buy from a seller who stocks parts.
If a product page can't answer those six clearly, that's information.
Where UV-C sits in your water setup
UV-C isn't a filter replacement. It's a partner.
The order matters. UV-C light has to shine through the water to reach the bugs. Cloudy water blocks the light. Any sediment or organic gunk in the water becomes a shadow that pathogens hide behind.
So the setup goes:
Tank → Filter → UV-C → Tap.
Stage 1 (filter) makes the water clear. Stage 2 (UV-C) makes the water safe. Skip stage 1 and your UV dose drops. Skip stage 2 and the bugs pass through.
You can install UV-C without a filter and it'll do something — but you'll get the full benefit only when both stages are running. If you're building a proper system, spec them together.
Common questions caravanners ask
Does UV-C change the taste of my water?
No. It doesn't add anything. Water in, water out — just without the bugs.
Do I still need a filter if I have UV-C?
Yes. UV-C doesn't touch sediment, chlorine, or metals. And the UV works better when the water's already clear.
Will UV-C work on tank water that's been sitting for weeks?
Yes — this is exactly what UV-C is best at. Stored water grows biofilm and bacteria. UV-C sorts it out at the point of use.
What about bore water?
UV-C handles the biology. Bore water often carries iron, minerals, or hardness too — you'll want a filter in front of the UV to catch the sediment, and a heavier-duty setup if the bore water is particularly hard.
Will it run off my 12V system, or do I need 24V?
Either works. Our unit is 24V native and ships with a booster included, so you can wire it straight into a 12V caravan loom or a 24V setup without an inverter. Only draws power while water's flowing — real-world load on your battery bank is minimal.
How often do I have to replace anything?
Nothing scheduled. UV-C LEDs run for many thousands of hours. Occasional wipe-down of the sleeve is the only maintenance.
Can I install it myself?
Yes. 12mm push-fit plumbing, standard 12V or 24V wiring, two mounting clamps. If you've fitted a water filter before, this is the same job.
The Vankor UV-C LED Water Steriliser
We built the Vankor UV-C LED Water Steriliser for the caravan we'd want to be in. Instant-on LED. Runs on 12V or 24V — 24V native, with a booster included so it wires straight into any 12V caravan loom. Up to 8 LPM. 12mm push-fit fittings. Mounting clamps and power supply included. No mercury, no consumables, no warm-up.
$260 AUD, free shipping across Australia. Small-batch release — intro pricing while the first run lasts.
Pairs with our Pro Flow 12 High-Flow Water Filter for the complete tank-to-tap system. Filter first. UV-C second. Drink.
Both units are stocked in Australia. Both have parts you can actually get when you need them.
Two ways to get started:
→ Vankor UV-C LED Water Steriliser — $260. Second stage, kills bugs a filter can't catch.
→ The complete Vankor water filtration range — filter, UV-C, cartridges, and the bundle if you want the full system in one order.
Vankor builds gear for Australian caravan, camping and off-grid life. Fit once, forget about it. Made to a standard we'd stake our own trip on.