Reverse-cycle aircon vs gas heating: which is really cheaper to run? Reverse cycle usually wins — but it's not a reason to rip out working gas.

For most Australian households, yes. A reverse-cycle air conditioner is a heat pump that moves heat rather than burning fuel, so it runs at roughly 300 to 600 percent efficiency, while even the best gas heater tops out near 90 percent. Sustainability Victoria and ACT Climate Choices figures put reverse-cycle room heating at roughly 191 to 395 dollars a year, versus roughly 579 to 866 dollars a year for gas. The advantage narrows where gas is cheap and you are on expensive peak-only electricity with no solar, so it is cheaper for most households in most states rather than an absolute in every case. Run your own gas rate and tariff to be sure.

On Sustainability Victoria's mid-2025 figures, a 3.0-star reverse-cycle unit heating a 30 square metre room costs about 191 dollars a year, versus about 579 dollars for a gas room heater and about 860 dollars for an electric panel heater. For a whole 100 square metre home, multi-split reverse cycle is about 513 dollars and ducted reverse cycle about 721 dollars, versus about 1,540 dollars for gas ducted. ACT Climate Choices shows a similar 50 square metre pattern: about 244 to 395 dollars for reverse cycle versus about 866 dollars for a gas wall heater. These are modelled figures at assumed prices, so treat them as a guide and confirm current numbers at the source.

Yes, if you buy the right unit. ACT Climate Choices states that good reverse-cycle systems work even when it is minus 10 degrees Celsius in winter. The key is to ask whether a split system has an H2 rating, which means it will heat efficiently through a genuinely cold winter. In places like Ballarat, Canberra and Hobart, that cold-climate rating matters more than the headline star rating, because a unit's real-world efficiency does drop on the coldest nights and a cold-rated model holds its output better. The old idea that heat pumps stop working in the cold describes dated technology, not a modern cold-climate unit.

Usually not, if the gas heater still works well and has years of life left. Reverse cycle wins on running cost, but a new unit costs anywhere from roughly 600 dollars for a basic split up to around 15,000 dollars for ducted whole-home, and that upfront cost takes several years of running-cost savings to repay. Ripping out a working heater mid-life for running cost alone usually does not pay. In an existing home a working gas heater is not banned and does not have to be removed. The honest move is to switch to reverse cycle when you are buying new or when the gas heater dies, not before.

It is cheaper for most households in most states, but not a universal absolute. SolarQuotes' own per-capital gas prices show the gap swings with location: gas is around 5.6 cents per kilowatt-hour in Melbourne and 8.1 in Sydney but around 14.8 in Brisbane, while grid electricity runs 20 to 35 cents. Where you have cheap gas and an expensive peak-only electricity tariff with no solar, the running-cost advantage narrows. It rarely disappears, but the honest claim is cheaper for most households in most states, not every state. If you have solar or heat during off-peak hours, the reverse-cycle case gets stronger.

CoP, or Coefficient of Performance, is how many units of heat a reverse-cycle system delivers per unit of electricity it uses. ACT Climate Choices figures put split systems at an average CoP around 3.7, up to 6.4 for the best, and ducted systems around 3.5 to 5.0, equivalent to roughly 350 to 640 percent efficiency. It matters because a system with a CoP of 6 uses half the electricity of one with a CoP of 3 to produce the same warmth, so a higher-CoP model directly lowers your running cost. Real-world seasonal CoP drops on the coldest nights, so in cold climates choose a cold-rated unit rather than judging by one headline number.