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Why most heating-and-cooling advice gets it wrong
Most guides treat heating and cooling as two separate problems with two separate answers: a heater for winter, an aircon for summer. That framing is how households end up paying twice, running gas ducted heating and a split system side by side, when one reverse-cycle unit was designed to do both jobs.
The bigger blind spot is the gas connection itself. The conversation stops at "which heater is cheaper to run" and never reaches the daily gas supply charge, a fixed cost you pay every day of the year just to keep the gas on. If gas is only earning its keep for a few months of heating, you're paying that charge through every summer day too.
How the costs actually work
There are two costs in play: what you spend making warmth and coolth, and what you spend just having the connections.
One unit, both jobs
A reverse-cycle air conditioner cools by moving heat out in summer and heats by moving heat in during winter. The same hardware, flipped. So a single unit replaces both a dedicated heater and a cooler, with one purchase, one install and one thing to service. On running cost it beats gas for heating and matches any aircon for cooling.
The standing-cost trap
Every energy connection carries a daily supply charge whether you use it or not. Keep both electricity and gas connected and you pay two standing charges all year. If gas exists in the house only to run winter heating, its supply charge (often around $1 to $1.30 a day) is dead money for the eight or nine months you aren't heating. Going all-electric with one reverse-cycle system removes that second standing charge entirely.
Two systems vs one: the yearly cost
This calculator compares a year of gas heating plus separate aircon cooling (and the gas supply charge that rides along) against a single reverse-cycle unit doing both. Every figure also appears in the worked example below.
Two systems vs one, per year
Heating + cooling + standing charges. Edit any input.
Two-system case: gas heating at 80% efficiency (4 c/MJ) + your cooling cost + a full year of gas supply charge. One-system case: reverse-cycle heating (COP 4) + the same cooling, no gas connection. Rates are editable defaults, not your plan.
Worked example (the calculator's default). 3 kW heat, 6 h/day, 100 winter days, $200 summer cooling, gas supply $1.10/day, electricity 30 c/kWh:
| Setup | What's in it | Cost for the year |
|---|---|---|
| Two systems | Gas heat ~$324 + cooling $200 + gas supply ~$401 | ~$925 |
| One reverse-cycle | RC heat ~$135 + cooling $200, no gas | ~$335 |
About $590 a year saved, and roughly $400 of that is just the gas supply charge you stop paying.
How Aussies overpay without realising it
Paying a daily gas supply charge all year to run heating for three months is the quiet, recurring waste in this setup.
The split system already heats. Buying a separate heater duplicates a job the aircon does more cheaply.
Two systems mean two things to maintain and replace. One unit halves that ongoing cost and hassle.
Whichever system you use, conditioning empty rooms wastes money. Target the rooms you're actually in.
The insider insight: the standing charge is the real saving
Everyone focuses on which heater is cheaper to run. The bigger money is usually hiding in the standing charges. A daily gas supply charge of around a dollar doesn't feel like much, but it's about $400 a year you pay just to keep gas connected, regardless of how little you burn. If gas only exists in your home to run winter heating, that's the single most wasteful line on the bill.
This is why the "go all-electric" move can save more than the running-cost difference alone suggests. Switching heating to a reverse-cycle unit you already own is good; using that switch to drop the gas connection entirely is where the real money is. The household that thinks in standing charges, not just usage rates, finds savings the usage-only comparison never shows.
What you should actually do
| Do this | Why it works |
|---|---|
| Use one reverse-cycle unit for both seasons | Heats more cheaply than gas, cools like any aircon, one thing to run and service. |
| If gas only heats your home, consider dropping it | Removes the daily gas supply charge, roughly $400 a year of dead money. |
| Check what else is on gas first | A gas cooktop or instant hot water may be worth keeping; weigh it before disconnecting. |
| Heat and cool the rooms you use | Targeting occupied rooms cuts running cost whichever system you keep. |
| In VIC, NSW, SA, QLD, ACT: compare plans against the DMO/VDO | Going all-electric on the right plan compounds the saving. |
In Western Australia (Synergy) and the Northern Territory (Power and Water) there's no retailer to switch to. For the running-cost detail see our home heating guide and air conditioning guide.
Why this matters right now
As gas prices and supply charges climb, the case for one all-electric reverse-cycle system gets stronger every year. For homes already running an aircon, the cheapest heating and cooling setup is often the one that drops a connection rather than adds a device.
The takeaway: let one system do both jobs, and count the standing charges. The saving from ditching a gas connection you barely use can dwarf the difference between heaters.
Frequently asked questions
Current figures — last updated 2026-06-13
All values in AUD and Australian units. Volatile figures change; check your own plan before relying on them.
| Reverse-cycle heating efficiency (COP) | 3–5 units of heat per unit of power |
|---|---|
| Typical gas daily supply charge | ~$1.00–$1.30/day (~$365–$475/year) [verify: your plan] |
| Gas heater efficiency | ~80% |
| Typical electricity rate | ~25–35 c/kWh [verify: your plan] |
| Typical gas usage rate | ~3–5 c/MJ [verify: your plan] |
| Reference price (NSW, SA, SE QLD / VIC) | AER DMO / ESC VDO [verify: current value] |
Sources: energy.gov.au, Australian Energy Regulator (DMO), ESC Victoria (VDO), retailer Basic Plan Information Documents, manufacturer specifications.