Gas runs half your caravan. Your cooktop, your hot water, your three-way fridge, sometimes your space heater and even your barbecue all pull from the same bottles sitting in the front boot. Get the setup wrong and you’re either running dry in the middle of a paddock or, worse, dealing with a leak you didn’t know about. Get it right and you’ll go weeks between refills without a second thought.
This guide covers what to buy: the bottles themselves, the regulators that step the pressure down safely, and the fittings that tie it all together. We’ll tell you what’s worth spending on and what’s overpriced.
What size gas bottles you actually need
Most caravans come from the factory with two 4.5kg bottles or a single 9kg. The size you run comes down to how much gas you burn and how often you want to refill.
A typical couple cooking with gas, running a gas hot water service and occasionally a three-way fridge on gas will burn through roughly 4.5kg every 10 to 14 days. Run two 4.5kg bottles on a changeover and you’ve got three to four weeks before both are empty. That’s the sweet spot for most rigs.
Two 9kg bottles double your range but add weight and take up more room in the boot. A full 9kg steel bottle weighs about 16kg. Two of them is 32kg sitting on your drawbar, which eats into your ball weight. If you’re already close to your limits, that matters.
4.5kg bottles are far easier to refill in remote areas. Plenty of small-town servos and stations swap 9kg bottles but won’t refill your own, and 4.5kg refills are handled by more places than you’d expect.
Which sizes suit which travellers
- Solo travellers and couples: 2 x 4.5kg is plenty. Light, easy to lift, weeks of range.
- Families: 2 x 9kg if you’re cooking big meals and running gas hot water daily.
- Off-grid free campers: 2 x 9kg, because you’ll be a long way from the next refill.
- Anyone weight-conscious: stick with 4.5kg or look at composite bottles.
Steel vs composite bottles
Steel bottles are the default. They’re cheap, tough, available at every servo and Bunnings in the country, and they last decades. The downsides are weight and rust. A neglected steel bottle sitting in a wet boot will corrode, and once the paint’s gone the rust follows.
Composite bottles (like the Viking or Safefill range) are lighter by around 40 per cent, won’t rust, and are translucent so you can see the gas level. They cost two to three times more up front and, critically, not everywhere will refill or swap them. That last point kills them for a lot of remote travel.
Our take: for a big lap, run steel. The refill and swap network is what makes it work. Composite is a nice luxury if you’re weight-sensitive and sticking to the coast and major highways, but it becomes a liability once you’re inland.
Every gas bottle in Australia must be re-tested and stamped every 10 years. Check the date stamp on the collar before you buy secondhand or before a swap. An out-of-date bottle can be legally refused for refilling, and it’s illegal to fill.
Regulators: single stage, changeover, and safety
The regulator drops the high pressure from the bottle down to the low pressure your appliances need (2.75 kPa in Australia). This is the part of the system most people ignore until it fails, usually on a Sunday afternoon miles from a caravan spares shop.
Single vs automatic changeover
A single-stage regulator connects to one bottle. When it runs dry, you manually switch to the other. Cheap and simple, but you’ll always run out at the worst moment.
An automatic changeover regulator connects to both bottles at once and switches over automatically when the first runs empty. A little indicator turns from green to red so you know to refill the spent bottle at your convenience. This is the upgrade worth making. You never lose gas mid-cook and you never run both dry at once.
With an automatic changeover, when the indicator shows red, reset the selector to the freshly filled bottle so the system draws from full again. If you forget, you’ll drain both without warning.
Compliance and the POL vs Type 21 change
Australia has phased in Type 21 (also called quick-connect or LCC27) bottle valves to replace the old POL fittings. New bottles increasingly come with Type 21 valves, which are safer and hand-tightened. If you’re buying new bottles and a new regulator, make sure they match. Adaptors exist to bridge old and new, but running matched fittings is cleaner and safer.
Hoses, fittings and adaptors
Gas hoses perish. UV, heat and age all break down the rubber, and a cracked hose is a leak waiting to happen. Replace pigtail hoses (the flexible ones from bottle to regulator) every few years regardless of how they look. They’re cheap and it’s not worth the risk.
Worth carrying as spares:
- A spare pigtail hose matched to your regulator type
- A POL-to-Type 21 adaptor, so you can connect to either valve type at a swap
- A bayonet fitting and hose for running an external barbecue off your caravan gas
- A small tube of leak detection fluid (or use soapy water)
Any permanent gas work on a caravan (fixed lines, appliance connections) must legally be done by a licensed gasfitter and certified. You can connect and disconnect your own bottles and pigtails, but don’t modify the fixed system yourself.
Our top gas gear picks
✔ Pros
- Never run fully dry unexpectedly
- Refill spent bottle at your leisure
- Works with both bottle sizes
✗ Cons
- Costs more than a single-stage reg
- Needs correct pigtails for your valve type
✔ Pros
- Cheap and universally available
- Swap or refill anywhere
- Long service life
✗ Cons
- Heavy compared to composite
- Will rust if neglected
Handy extras worth carrying
Refilling, swapping and testing on the road
You’ve got two options on the road: swap-and-go or refill. Swap is faster and available at most servos, Bunnings and hardware stores for 9kg bottles, usually $25 to $30 a swap. The catch is you hand over your good bottle and might get a scruffy one back, and you pay a fixed price even if your bottle wasn’t empty.
Refilling gets you full value and keeps your own bottle, but not every servo does it. Look for signs saying “gas refills” or ask at the counter. Refills are typically cheaper per kilo than swaps and are how you keep composite bottles topped up.
Test every connection with soapy water after connecting a bottle. Brush it over the fittings and watch for bubbles. If it bubbles, you’ve got a leak. It takes 30 seconds and it’s the single best habit you can build.
Keep an eye on your bottle levels before you head somewhere remote. Pour warm water down the side of a steel bottle and feel for the cold line: that’s roughly where the gas level sits. Simple, and it works when you don’t have a gauge.
- Run two steel bottles on an automatic changeover regulator: it’s the setup that never leaves you without gas.
- 4.5kg bottles are lighter and easier to refill remotely; 9kg gives more range for families and off-gridders.
- Steel beats composite for a big lap because the refill and swap network is everywhere.
- Replace pigtail hoses every few years and leak-test every connection with soapy water.
- Check the 10-year test stamp before buying or swapping any bottle.
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