A caravan gas heater is still the most common way vans leave the factory warm, but “gas heater” covers two very different animals: fixed flued units you can safely run all night, and unflued portables that belong in the annexe and nowhere else. This guide sorts the two out, covers the Australian legal rules, and gives you our top picks for 2026.
Flued vs Unflued: The Difference That Matters
Before you spend a dollar, understand this, because it is the whole ballgame. Two completely different products both get called “caravan gas heaters”, and only one of them is safe to run while you sleep.
Fixed Flued Heaters (The Safe-Overnight Kind)
A fixed flued heater is built into the van. It burns LPG in a sealed combustion chamber and vents every bit of the exhaust, and all the moisture that comes with it, outside through a flue in the wall or floor. The air it puts into your living space never touches the flame. That sealed design is exactly why you can run one overnight with the van shut up against the cold. This is what brands like Truma make, and it is what turns up factory-fitted in most new Australian vans.
Unflued Portable Heaters (Annexe and Outdoors Only)
An unflued portable, the radiant or catalytic type that runs off a gas cartridge or a hose to your bottle, has no flue. Every product of combustion, including carbon monoxide and a surprising amount of water vapour, goes straight into the air around it. Run one in a closed van overnight and you are burning the oxygen you are breathing and pumping CO into the space at the same time. These heaters have a place, taking the chill off the annexe on a cold evening, but that place is never a sealed sleeping space.
Never run an unflued portable gas heater inside a closed caravan overnight. It consumes the oxygen in your living space and produces carbon monoxide, which can kill you in your sleep. Portables are for ventilated annexe or outdoor use only. Fit a carbon monoxide alarm in your van regardless of what type of heater you run.
The Legal Bit: Who Can Install a Gas Heater
A fixed LPG heater is a gas appliance plumbed into your van’s gas system, and in Australia that is regulated work. You cannot legally fit one yourself. A fixed gas heater must be installed by a licensed gas fitter, who then issues a compliance certificate. Skip that and you have voided your insurance and created a genuine safety and legal problem.
There is a second catch worth knowing before you shop. In practice, Truma is effectively the only brand certified for legal fixed LPG heater installation in Australian caravans. That is why nearly every new van rolls out with a Truma unit and why our fixed picks below are all Truma. It is not brand loyalty, it is what is certified to go in your wall.
If your van already has a factory Truma heater, a gas fitter can service and repair it Australia-wide. Keep the model number handy, it makes sourcing the right parts on the road far quicker.
What to Look For When Buying
Once you have decided between a fixed unit and a portable, these are the things that actually separate a good buy from a regret.
- Flued or unflued: the first and biggest decision. Flued for overnight in-van heat, unflued only for the annexe. Do not blur the line.
- Heat output (kW): 2 to 2.8kW warms most single-axle vans. Step up to 3.7 or 5kW for large tandem-axle vans or serious cold. Portables are rated in BTU: 7,000 BTU is plenty for an annexe.
- Power draw: fixed gas heaters need 12V for the fan and control board, but sip it. A VarioHeat pulls just 0.65 to 2.75A, so your battery and solar barely notice, which is a real edge over a 2,000W electric heater off-grid.
- Gas consumption: roughly 100 to 220 g/hr for a fixed unit. A 9kg bottle runs a long time, but plan bottle swaps into remote legs where LPG gets scarce.
- Noise: the VarioHeat is whisper quiet, the older S-series has a bit more fan hum. You sleep next to this, so it counts.
- Child safety: radiant panel heaters like the S-series get hot on the front face. Families with toddlers should factor that in or choose a convection-style VarioHeat.
- Moisture: even a flued gas heater adds slightly more cabin moisture than diesel. Not a dealbreaker, but crack a vent if condensation is an issue.
- Certified install: budget $300 to $600 for a licensed gas fitter on top of the unit price. It is not optional.
Our Top Picks for 2026
We have split the picks the way you should think about them: fixed flued units first, the ones that live in your van and heat it overnight, then the annexe-only portables. Prices are the unit only unless noted, so add certified install for the fixed heaters.
✔ Pros
- Flued, so safe to run overnight
- Whisper quiet and fast to warm up
- Very low 12V draw, off-grid friendly
- The certified, widely-supported standard
✗ Cons
- Certified gas-fitter install required
- Tied to your LPG bottle supply
- Adds a little more cabin moisture than diesel
✔ Pros
- Flued, certified and long proven
- 5kW option for big vans
- Optional fan kits for better circulation
- Flame-effect panel many owners like
✗ Cons
- Bulkier and older than the VarioHeat
- Radiant front gets hot, watch it with toddlers
- Certified gas-fitter install required
✔ Pros
- Cabin heat and hot water in one unit
- Saves precious space in a full-time van
- Flued, certified and Truma-supported
- 4E has the grunt for large vans
✗ Cons
- The most expensive option here
- Certified gas-fitter install required
- Overkill if you only want cabin heat
✔ Pros
- Cheap and genuinely portable
- Runs off a cartridge or your bottle
- Good safety kit: ODS, anti-tilt, guard
- No install, no wiring
✗ Cons
- Unflued, so annexe and outdoor use only
- Never safe in a closed van overnight
- Adds moisture and CO to the air around it
✔ Pros
- The cheapest annexe heater here
- Simple, portable, no install
- Fine for an open annexe on a cold night
✗ Cons
- Unflued, so annexe and outdoor use only
- Never safe in a closed van overnight
- Basic build for the money
Quick Comparison Table
Here is how the picks stack up side by side. Note the split between the flued units you can run overnight and the unflued portables you cannot.
| Heater | Price | Type | Output | Overnight? | Best For |
|---|---|---|---|---|---|
| Truma VarioHeat Eco/Comfort Pick | ~$1,819+ | Fixed, flued | 2.8 to 3.7kW | Yes | Most vans |
| Truma S3004 / S5004 | ~$1,200 to $2,000 | Fixed, flued | 3.4 to 5kW | Yes | Larger vans, radiant |
| Truma Combi 2E / 4E | ~$2,654 to $3,224 | Fixed, flued | 2 to 4kW + water | Yes | Heat + hot water |
| Companion Portable Propane Annexe | ~$259 | Portable, unflued | 7,000 BTU | No | Annexe / outdoor |
| Gasmate Portable Camping Budget | ~$199 | Portable, unflued | Radiant | No | Budget annexe |
Frequently Asked Questions
Can I run a gas heater in my caravan overnight?
Only a fixed, flued unit like a Truma. Because the combustion is sealed and the exhaust vents outside, it is safe to run with the van shut up. Never run an unflued portable overnight in a closed van, it produces carbon monoxide and consumes your oxygen.
Do I need a licensed gas fitter to install one?
For any fixed LPG heater, yes. It is plumbed into your van’s gas system and must be installed by a licensed gas fitter who issues a compliance certificate. Portables need no install, but they are outdoor and annexe use only.
Why is nearly everything Truma?
Truma is effectively the only brand certified for legal fixed LPG heater installation in Australian caravans, which is why it comes factory-fitted in most new vans and why our fixed picks are all Truma. It is a certification reality, not a preference.
Gas or diesel for a caravan heater?
Gas is common, quiet and cheap to fit if the van is already plumbed for it. Diesel gives drier heat, is cheaper to run off-grid and frees you from bottle swaps in remote country. It comes down to your setup and where you travel, which we break down in the guides below.
- Fixed flued heaters are safe to run overnight; unflued portables are annexe and outdoor use only, never in a closed van.
- The Truma VarioHeat is the best fixed gas heater for most vans, with the Combi worth it if you also want hot water.
- A fixed LPG heater must be installed by a licensed gas fitter, and in practice Truma is the only certified brand.
- The Companion and Gasmate portables are cheap annexe warmers, but respect the outdoor-only rule without exception.
- Fit a carbon monoxide alarm in your van no matter which type of heater you run.
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