Gas heaters: Running costs, specs and price compared

Anula Wiwatowska
May 30, 2024
Icon Time To Read8 min read
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Gas heaters have long been praised as cost effective ways to heat your home, but that isn't neccessarily the case. Gas' rising prices may actually make these heaters pricier in the long run, especially if you're in a cooler climate.

In this guide we look at both indoor and outdoor gas heaters, compare popular models, and help you figure out how to find the best one for you. Or even decide if it is a good option for you at all.

Indoor gas heaters compared

Each brand tends to have similar heaters across their range but with different power levels. We've pulled together some of the most accessible options across Australia to give you an idea of how these major manufacturers compare.
Brand
Brand
Gas usage
Coverage
Flued
Price range
Rating
Retailers
Omega Altise 25MJOmega Altise 25MJ Gas Convection Heater - White25MJ/h97m2 con
RRP
$1249
4 out of 5 stars
4
Omega Altise 15MJOmega Altise 15MJ Portable Gas Convection Heater - Graphite15MJ/h59m2 con
RRP
$1049
3.8 out of 5 stars
3.75
Bromi Stratos 5Bromic Stratos Brahma 5 Indoor 4.3kW Gas Heater - White18.5MJ/h43m2 pro
RRP
$2499
3.8 out of 5 stars
3.75
Bromi Stratos 7Bromic Stratos Brahma 5 Indoor 4.3kW Gas Heater - White27.5MJ/h63m2 pro
RRP
$2899
3.8 out of 5 stars
3.75
Rinnai Avenger 25rinnai avenger25MJ/h97m2 con
RRP
$1799
3.5 out of 5 stars
3.5

What we look for in an indoor gas heater

Price Tag
Price

No matter what product we assess, we always consider pricing. We weight up the total value of the product by looking at how the price, features, and coverage balance against each other. The more you get, for the smaller price tag, the better for our score and your wallet.

Bullhorn
Ongoing running costs

For a long time gas heaters were thought of to be cheaper than electrical heaters. With growing gas prices, this isn't neccessarily the case anymore. You'll need to consider the Megajoules per hour (MJ/h) usage of the heater, and compare that to your gas rate to see how much it is likely to cost you.

Info Box
Coverage in climate zones

Unlike electric heaters that give a one-size-fits-all coverage number, indoor gas heater efficiency can vary by climate zone. The same heater will cover less area in a temperate zone than it will in a subtropical zone, so it is important to check how these stack up.

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Flued or unflued

Flued gas heaters run used gas outside, while unflued heaters keep that gas in the room. While there are benefits to both, flued heaters are safer and legal to use in more places. There generally is a higher cost involved with flued heaters though, not only for the unit themselves, but the building works involved.

Indoor gas heaters

Under the right circumstances indoor gas heaters can be an effective, and affordable way to heat your home, but there are some caveats.

Considering that gas is a limited energy source the prices have been rising in recent years, so the running costs have changed a lot. We'll get into that more later on, but on average a good electric or oil heater is probably going to be cheaper to run than a natural gas heater over winter.

They also perform differently depending on your climate zone, being the least effective in cool area like Victoria and Tasmania - where you need them the most. A 25MJ gas heater can handle 97m2 in Queensland, but only 53m2 down south.

Then we get into the health risks associated with indoor gas heaters. Due to the emissions associated with these devices there are carbon monoxide and nitrous oxide risks which can lead to health problems. These are fewer on flued gas heaters that pump the gas outside, but these are also more expensive to buy and install. Unflued heaters on the other hand are illegal to use in bedrooms, bathrooms and other small rooms, so your options are limited.

There is plenty to consider when it comes to deciding on whether an indoor gas heater is right for you. If it looks like it will work for your household then we've compared some of the more popular brands below.

Omega Altise 25MJ Gas Convection Heater - White
Features
  • MJ/h usage: 25MJ/h
  • Coverage: 90m2
  • Flued: No
  • The Omega Atlise gas heater has excellent coverage for its gas usage, and a relatively low price for the category. Able to cover up to 97m2 in warmer temperate zones and 90m2 on average, it packs a punch for its 25MJ/h usage. With a 7 year warranty, the Atlise 25MJ seems well suited to stick around.

    Notably it is an unflued heater so you'll need to make sure you have a well ventilated area to use it in.

    Omega Altise 15MJ Portable Gas Convection Heater - Graphite
    Features
  • MJ/h usage: 15MJ/h
  • Coverage: 59m2
  • Flued: No
  • Similar to its bigger brother, the Atlise 15MJ has excellent performance for its power. With gas usage ranging from 9-15MJ it is a more economic option for smaller spaces. Since this model is also unflued it is portable so can be moved around the house as needed.

    Bromic Stratos Brahma 5 Indoor 4.3kW Gas Heater - White
    Features
  • MJ/h usage: 18.5MJ/h
  • Coverage: 43m2
  • Flued: Yes
  • As a flued device, the Bromic Stratos 5 is a more expensive from the get-go. Its gas usage is also quite high for its average coverage of 43m2, which can lead to a hefty bill at the end of the season.

    You do get the luxury of not having to worry as much about the health implications of gas, but clearly you need to pay a pretty penny for it. Bromic heaters all come with a two year warranty.

    Bromic Stratos Brahma 7 Indoor 6.3kW Gas Heater - White
    Features
  • MJ/h usage: 27.5MJ/h
  • Coverage: 63m2
  • Flued: Yes
  • A step up from the Bromic 5, the Bromic 7 is both more expensive and more powerful. Rated to 63m2, and using between 19.3-27.5MJ/h, it is still less fuel efficient than the Omegas.

    All Bromic heaters have a thermostat and a remote control which gives you more control of your environment.

    Rinnai Avenger 25 Unflued Gas Convector Heater with 3m Hose - White
    Features
  • MJ/h usage: 25MJ/h
  • Coverage: 97m2
  • Flued: No
  • Covering 85m2 on average, the Rinnai Avenger 25 is an unflued and portable gas heater. Equipped with Economy mode which only uses 8.5MJ/h, it has the widest gas usage range out of the heaters we have compared. If you run it on low, it can be quite affordable.

    With a 5 year warranty, child lock, and dual timers, it gives you a lot for a slightly higher than average price.

    How much does it cost to run an indoor gas heater?

    And are they energy efficient?

    Gas prices have gone up so the cost of running a natural gas heater has gone up with it.  While these used to be pitched as an a cheap option for keeping your house warm, that simply isn't the case anymore for a lot of Australia. According to current usage costs, a 25MJ heater would cost over $750 to run 8 hours per day over winter.

    Energy Made Easy released data showing that the average cost per MJ in Australia ia $0.0411. This price itself is about 10c cheaper than the average kW of electricity cost across the country, but because gas requires heavier consumption the price adds up. A low gas usage heater using 6MJ/h is about the same price to run as a mid-powered 1800W electric heater. While 1800W is a pretty standard setting for electric heaters, it is hard to come by a gas heater that goes down that low. 

    In cooler climates how much space those MJ can actually heat up changes as well. 25MJ in snowy regions can generally handle around 70m2, while in the north the same heater can warm up 125m2. Depending on the Megajoule (MJ) usage of the heater, and the climate zone where you live, it may be cheaper to opt for an electric heater instead.

    Heater
    Megajoule range
    Cost per hour
    Omega Altise 25MJ13 - 25MJ/h$0.53 - $1.03
    Omega Altise 15MJ9 - 15MJ/h$0.37 - $0.62
    Bromic Stratos 513.4 - 18.5MJ/h$0.55 - $0.76
    Bromic Stratos 719.7 - 27.5MJ/h$0.81 - $1.13
    Rinnai Avenger 258.5 - 25MJ/h$0.35 - $1.03

    Outdoor gas heaters compared

    Outdoor gas heaters are are relativey similar across the board. You'll mostly want to look at gas usage, and figure out whether you'd rather have heat above you, or at chest height. Here are how some popular Bunnings gas heaters compare.
    Brand
    Heater type
    Gas usage
    Price range
    Rating
    Retailers
    Mimosa Lava Matte Black Outdoor Gas Patio HeaterLPG gas38.5MJ/h
    $189
    3.3 out of 5 stars
    3.25
    Enders 76cm Sliver Fancy Patio HeaterLPG gas28MJ/h
    $189
    3.3 out of 5 stars
    3.25
    Mimosa Stainless Steel Outdoor Area Gas HeaterLPG gas37.7MJ/h
    $229
    3 out of 5 stars
    3
    Mimosa Matte Black Outdoor Area Gas HeaterLPG gas37.7MJ/h
    $229
    3 out of 5 stars
    3

    What we look for in an outdoor gas heater

    Price Tag
    Price

    No one wants to throw money at something that isn't worth it. We look at the price to feature ratio of outdoor gas heaters to help calculate the score.

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    Ongoing running costs

    Even if you grab a bargain at the checkout, the ongoing running costs of an outdoor heater could burn you. We look at the gas usage and weigh it agains the cost of LPG to give you a good indication of how much you'll really need to invest for an outdoor gas heater.

    Info Box
    Heating efficiency

    While the outdoors is hard to control we consider the overall heating efficiency of these gas heaters. If you only have a small space to cover then you may be able to get away with a cheaper option without sacrificing warmth.

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    Durability

    If it is in the elements, it needs to be protected from them. We rate stainless steel outdoor heaters highest since the alloy is more corrossion resistant. Mild steel has been popping up quite a bit in matte black heaters especially - this type of metal is less resiliant to the outdoors so it is worth taking that into account.

    Outdoor gas heaters

    When I say outdoor gas heater you know exactly what I'm talking about. A tall mushroom, or a low cylinder, with an ignition button that is notoriously finnicky. These styles are relatively similar across brands with similar coverage and gas usage across the board.

    There isn't too much to disect here so we compared some of the most popular gas heaters at Bunnings below.

    Mimosa Lava Matte Black Outdoor Gas Patio Heater
    Mimosa Lava Matte Black Outdoor Gas Patio Heater
    3.3 out of 5 stars
    3.25
    RRP
    $189
    Features
  • Power usage: 38.5 MJ/h
  • Build: Mild steel
  • Safety: Tip-over and flame failure protect
  • Coated with a brushed, mild steel the Lva Matte Black from Mimosa is everything you think of when you think about an outdoor heater. It covers up to 17m2 and uses a whopping 38.5MJ/h of gas.

    Since it is made of mild steel it may hold up worse over time than comparable stainless steel models.

    Enders 73cm Silver fancy patio heater
    Enders 76cm Sliver Fancy Patio Heater
    3.3 out of 5 stars
    3.25
    RRP
    $189
    Features
  • Power usage: 28MJ/h
  • Build: Stainless steel
  • Safety: Tip-over protect
  • Rather than just standing tall, the Enders patio heater can retract down to give chest-level heat as well. This novelty aside, Enders doesn't provide coverage information so we can't be sure exactly how much space this can warm up. Since it uses 28MJ/h, which is less than the Mimosa above, we can assume it is a bit less than 17m2.

    Mimosa Stainless Steel Outdoor Area Heater
    Features
  • Power usage: 37.7MJ/h
  • Build: Stainless steel or mild steel for matte black
  • Safety: Tip-over and flame failure protect
  • Available in either stainless steel, or matte black in mild steel, this pedestal area heater is the other gas heater you would think of. Sitting at chest height this may be better for wide open spaces. Even though these devices are a little bit more expensive than the mushroom heaters, they also use less gas so you should be able to get more time out of the same gas cyclinder.

    How much does it cost to run an outdoor gas heater?

    And are they worth the money?

    Unlike indoor heaters, outdoor ones aren't really meant to run for a long time and that is excellent for your back pocket. Your usual outdoor gas heater is an absolute guzzler, so couple that with the cost of an 8.5kg gas cylinder and you're looking at some high price tags.

    Gas is measured in Megajoules per hour (MJ/h), but LPG gas cylinders are measured in kg so it is already confused to start. A leading LPG supplier ELGAS says that an 8.5kg tank holds the equivelant of 417MJ which is around 17 litres of gas. With the price of a swap-and-go sitting around $31.50 per cylinder, we calculated that an hour of outdoor gas heater use will cost more than $2. For comparison a 25MJ indoor heater will set you back $1.03 per hour.

    Heater
    Power range
    Cost per hour
    Mimosa Lava Matte Black Outdoor Gas Patio Heater38.5 MJ/h$2.91
    Enders 73cm Silver fancy paito heater28 MJ/h$2.12
    Mimosa Matte Black Outdoor Area Gas Heater37.7 MJ/h$2.85
    Anula Wiwatowska
    Written by
    Anula Wiwatowska
    Anula is the Content and Social Media Editor within the Reviews.org extended universe. Working in the tech space since 2020, she covers phone and internet plans, gadgets, smart devices, and the intersection of technology and culture. Anula was a finalist for Best Feature Writer at the 2022 Consensus Awards, and an eight time finalist across categories at the IT Journalism Awards. Her work contributed to WhistleOut's Best Consumer Coverage win in 2023.