Cost to run ducted heating: gas vs electric

How gas ducted heating and electric reverse-cycle ducted systems compare on running cost in Australia, and how to keep winter heating bills under control.

By EnergySorted Editorial Team · Updated 27 July 2026 · 6 min read

Two very different ways to heat a house

Ducted heating warms the whole home through vents fed by a central unit, and in Australia that unit is usually either a gas furnace or an electric reverse-cycle (heat pump) system. They feel similar from the vent, but their running costs work in completely different ways because one burns fuel and the other moves heat.

A gas ducted furnace turns most of the gas it burns into warm air. A modern condensing unit is quite efficient, an older one much less so. You pay for gas in megajoules, plus a daily supply charge for the connection. An electric reverse-cycle ducted system is a heat pump: for each unit of electricity it draws, it delivers roughly three units of heat, which is why its running cost can undercut gas even though electricity costs more per unit of energy.

Comparing the running cost fairly

The fair comparison is cost per unit of useful heat delivered into the house, not the sticker rate of each fuel. Gas might look cheap per megajoule, but a furnace loses some of that energy up the flue, while a heat pump multiplies each kilowatt-hour of electricity into several times as much warmth. For many homes those two effects roughly cancel out, and the winner depends on local rates and the age of the equipment. Our broader look at gas versus electricity running costs works through the same maths across the whole home.

As a rough guide, an efficient reverse-cycle ducted system delivering heat with a coefficient of performance around 3 draws maybe 2 to 4 kW to heat a house, or around 70 cents to $1.40 an hour at 35c/kWh. Gas ducted heating for the same house often lands in a similar or slightly higher hourly range once you include the daily supply charge, though older gas furnaces and cheap gas rates can shift it either way.

The honest answer is that there is no universal winner. If you already own working gas ducted heating, the running-cost saving from switching to electric has to pay back a big installation cost. If you are replacing an old system anyway, an efficient reverse-cycle system is usually the cheaper long-term choice, and it doubles as summer cooling.

Seasonal and regional notes

Heat pumps lose some efficiency in very cold weather because there is less heat in the outside air to move, so in an alpine or frosty inland climate a gas furnace can close the gap on the coldest mornings. In milder coastal climates the heat pump keeps its efficiency advantage almost year round.

Gas ducted heating dominates the winter quarter of the bill in cold-climate cities like Melbourne, Canberra and Hobart. A home that runs it hard can use several times more gas in July than in a mild month, which is why the winter bill can be a shock even when the annual average looks reasonable. Watching that seasonal spike, and knowing what drives winter heating costs, is the key to keeping it in check.

How to cut ducted heating costs

Zone the system so you only heat rooms in use rather than the whole house. This is the single biggest saving on ducted heating.
Set the thermostat around 18-20°C; every degree higher meaningfully increases fuel or electricity use.
Seal draughts and close doors to unheated zones so warm air is not leaking away.
Use a timer so the house is warm for waking and evenings, not heating an empty home all day.
If you run an electric reverse-cycle system and have a time-of-use tariff, pre-heat late in the off-peak window rather than during the evening peak.
Service the unit before winter. A clean filter and tuned burner or coil keep it running at rated efficiency.

Where EnergySorted fits

Whether you heat with gas or electricity, the running cost is the usage multiplied by your rate, and the rate is the part you can change today. EnergySorted compares your real usage across every electricity and gas plan without taking retailer commissions, so the ranking reflects what you would actually pay through a cold winter rather than a marketing figure.

If you are weighing up a switch from gas to electric heating, the comparison also helps you see the electricity side clearly, including whether an off-peak or time-of-use plan suits a heat pump you run on a timer. The Bill Health Score then keeps an eye on whether your plan stays competitive as retailers quietly move you off introductory rates.

Frequently asked questions

Is gas or electric ducted heating cheaper to run?

It depends on your rates and equipment. An efficient reverse-cycle (heat pump) system delivers about three units of heat per unit of electricity, which often matches or beats gas ducted heating on running cost despite electricity costing more per unit of energy. There is no universal winner. It comes down to local rates and the age of your system.

How much does ducted heating cost per hour?

An efficient electric reverse-cycle ducted system typically draws 2 to 4 kW to heat a house, or roughly 70 cents to $1.40 an hour at 35c/kWh. Gas ducted heating for the same home often lands in a similar range once the daily supply charge is included.

Should I switch from gas ducted heating to a heat pump?

If your gas system still works, the running-cost saving has to pay back the installation cost, so the case is weaker. If you are replacing an old system anyway, an efficient reverse-cycle system is usually cheaper to run long term and adds summer cooling. Cost it on your real usage before deciding.

Why is my ducted heating bill so high in winter?

Ducted heating warms the entire house at once, so it is the largest seasonal load in most cold-climate homes. Running it across the whole house all day is the main cause of a winter bill spike. Zoning to occupied rooms and using a timer are the biggest fixes.

Does the energy plan I am on affect my heating costs?

Yes. Two identical homes running the same heater can pay very different amounts because one is on a stale, overpriced plan. Comparing your real usage across available gas and electricity plans, as EnergySorted does, shows whether your rate is inflating the winter bill.

How can a heat pump deliver more heat than the electricity it uses?

It does not create heat, it moves it. A reverse-cycle system uses electricity to pump warmth from the outside air into your home, so one unit of electricity can shift roughly three units of heat. That is why the same trick makes a reverse-cycle unit far cheaper than a plug-in electric heater.

Does zoning ducted heating really save money?

Yes, and it is the single biggest lever on a ducted system. Heating only the rooms you are using, rather than the whole house, cuts the volume of air the unit has to warm. Closing doors and vents to unused zones and running the system on a timer together make the largest difference to a winter bill.

What thermostat temperature is best for ducted heating?

Around 18 to 20°C is the recommended range for living areas. Every degree higher noticeably increases the fuel or electricity the system uses, so nudging the thermostat down a degree or two and putting on a jumper is a genuine saving over a long winter.

Is gas ducted heating being phased out?

Some states are steering new homes away from gas connections, and electric reverse-cycle systems are increasingly the default for new builds and replacements. If your existing gas system works, there is no need to rush, but when it is time to replace, cost an efficient heat pump against gas on your real usage before committing.

Would solar or a battery help offset electric ducted heating?

Solar helps most with daytime heating, when your panels can power a heat pump directly. Winter mornings and evenings still draw from the grid unless you store energy, so it is worth reading whether a home battery stacks up before counting on it to cover heating.

General information only, current at the time of writing. Not financial advice. Rebate schemes and rules change; always confirm details with your retailer or state government energy site.