How to Heat a Pool in Australia: Every Option Compared
Four ways to put heat in the water, one way that is usually right, and the honest reasons you might pick a different one.
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There are four real ways to heat a pool in Australia: a heat pump, a gas heater, roof mounted solar collectors, or an electric element. For the overwhelming majority of Australian backyard pools the answer is a heat pump, because it delivers around five units of heat for every one unit of electricity it draws, which no other option comes close to. Gas wins on speed, solar wins on running cost if your roof suits it, and an electric element is the one you should almost never buy.
That is the whole article in a paragraph. Here is the detail, because the right pick depends on your pool, your roof and how you actually use the thing.
Option 1: Pool heat pump
A pool heat pump is an outdoor box that pulls warmth out of the air and moves it into your pool water, and it is the default choice for Australian pools. It does not create heat, it relocates it, which is why a good one returns a COP of 5 to 6. One kilowatt of electricity in, five or six kilowatts of heat out.
Runs on 240V single phase in most sizes. Sits next to the filtration gear. Plumbs into the return line. Works from about 9kW for a plunge pool up to 35kW for a lap pool.
Best for: almost everyone. Family pools, plunge pools, spas, year round swimmers, people who care about the power bill.
The catch: it is slower than gas. A heat pump raises pool temperature by roughly half a degree to one degree per hour of running, so you warm a pool over a day or two, not over an afternoon. It also drops off in efficiency when the air gets genuinely cold, which matters more in Hobart than in Darwin.
Purchase price runs from $2,690 for the Guardian Eco Pro 9kW up to $9,451 for the Guardian Eco Pro 35kW. Our best seller sits in the middle at $3,799: the Midea M Series 20kW with WiFi. Prices current as of July 2026, AUD including GST.
Option 2: Gas pool heater
A gas pool heater burns natural gas or LPG to heat the water fast, and its only real advantage is speed. It will lift a pool several degrees in a few hours, which no heat pump will do. If you have a holiday house you use four weekends a year and want the pool hot by Saturday lunch, gas makes sense.
For everyone else it is an expensive habit. Gas heating typically costs somewhere around four to six times as much per degree as a heat pump, because burning gas is roughly 85 percent efficient at best while a heat pump is effectively 500 percent. Run a gas heater all season on a family pool and the bill gets genuinely ugly.
Best for: infrequent, on demand heating. Holiday homes, spas used occasionally, indoor pools that need heat right now.
The catch: running cost, plus you need a gas supply and enough of it. Many homes need the gas line upsized before a pool heater will run properly, and that is a plumber and a quote before you have heated a drop of water. We do not stock gas pool heaters, because we have never been able to recommend one to a homeowner heating a pool regularly.
Option 3: Solar pool heating
Solar pool heating pumps your pool water through black collectors on the roof and returns it warmed, and it has the lowest running cost of any option because the heat itself is free. You only pay to run the pump pushing water up there.
It is genuinely good when the conditions line up. You need a decent area of north facing or west facing roof, structurally sound, close enough to the pool that the plumbing run is not silly. Then you need sun, which is the problem: solar heats the pool on exactly the days you least need it and gives you nothing on a cold overcast week in June.
Best for: extending a summer season in a warm climate, on a house with the right roof, for an owner who does not mind that the water temperature follows the weather.
The catch: no control. You cannot set solar to 28 degrees and expect 28 degrees. Roof collectors also have a finite life in Australian sun, and re-roofing means pulling them off. Plenty of people end up running solar plus a heat pump, letting the sun do the easy work and the heat pump cover the gap.
If you are chasing the lowest possible running cost, a variable speed filtration pump such as the Madimack InverFlow Plus F300i is worth doing at the same time, since solar heating relies on that pump running.
Option 4: Electric element heater
An electric element heater is a resistive coil that turns one kilowatt of electricity into one kilowatt of heat, and it is the wrong answer for a swimming pool. A heat pump does the same job for about a fifth of the power. There is no scenario where an element is cheaper to run.
Elements still make sense inside a spa, where the water volume is small, you want 38 degrees on demand and the total energy involved is modest. That is why spa controllers like the SpaNet SV3 variable heat controller exist and sell well. For a 40,000 litre pool, an element is a way to donate money to your retailer.
Best for: spas and small volumes only.
The catch: the running cost, which is roughly five times a heat pump for identical heat.
The one thing that beats all four: a pool cover
A pool cover is the highest value thing you can buy for pool heating, and it is not even a heater. Most of the heat in an open pool leaves through the surface overnight by evaporation. Cover the water and you keep that heat instead of buying it again tomorrow.
A cover typically cuts heating energy by a large margin whatever heater you run, and it lets you drop a size on the heat pump you buy. Buy the cover first. Then buy the heater. Anyone who tells you otherwise is selling kilowatts.
Pool heating options compared
Straight comparison for a typical Australian backyard pool of 30,000 to 40,000 litres. Purchase figures for heat pumps are our current pricing; gas and solar figures are indicative installed market ranges, not Waternex pricing, and they vary a lot by site.
| Option | Typical purchase | Running cost | Speed | Temperature control | Verdict |
|---|---|---|---|---|---|
| Heat pump | $2,690 to $9,451 (unit) | Lowest of the powered options | Slow and steady, about 0.5 to 1 degree per hour | Full, set a temperature and hold it | The default for almost every pool |
| Gas heater | Roughly $2,500 to $5,000 plus gas work | Highest, around 4 to 6 times a heat pump | Fastest by far | Full, instant | Only for occasional on demand heating |
| Solar collectors | Roughly $3,000 to $6,000 installed | Lowest overall, you only run the pump | Weather dependent | None, the sun decides | Great with the right roof, useless in a cold snap |
| Electric element | Cheap to buy | About 5 times a heat pump | Moderate | Full | Spas only, never a pool |
| Pool cover | A few hundred dollars | Nil | Not a heater, a heat keeper | Not applicable | Buy one regardless of what else you choose |
So which one should you actually buy
Buy a heat pump, add a cover, and stop reading. That is the advice we give on the phone nine times out of ten, and it is right for a standard family pool that gets used across spring, summer and autumn.
Pick solar instead if you have the roof, live somewhere warm, and only want a longer summer rather than controlled temperature. Pick gas only if the pool sits idle for weeks and then needs to be hot on demand. Pick an element only for a spa.
Sizing is the next decision, and it matters more than brand. Work through What Size Pool Heat Pump Do I Need? before you shortlist a model.
Where our heat pump range fits
Waternex stocks pool heat pumps from 9kW to 35kW across five brands, so there is a match for every pool size and budget. A few anchor points.
| Pool | Suggested unit | Price |
|---|---|---|
| Plunge pool or spa, up to 20,000L | Guardian Eco Pro 9kW | $2,690 |
| Small family pool, 20,000 to 30,000L | SensaHeat ES 13kW | $3,200 |
| Standard family pool, 30,000 to 40,000L | Midea M Series 20kW WiFi | $3,799 |
| Standard pool, quiet inverter running | Guardian Platinum 20kW inverter | $6,290 |
| Standard pool, lowest running cost | Guardian Lux-V 20kW full DC inverter | $7,990 |
| Large or lap pool, 55,000L and up | Guardian Eco Pro 35kW | $9,451 |
Prices current as of July 2026, AUD including GST.
The Midea 20kW is the volume seller and has its own Midea 20kW guide if you want the full spec. Browse the lot in Heat Pumps for Pools & Spas or the wider Heat Pumps collection.
Frequently asked questions
What is the cheapest way to heat a pool in Australia?
Solar collectors have the lowest running cost because the heat is free, but a heat pump plus a pool cover is the cheapest way to get controlled, reliable warmth. Solar only works when the sun is out, so many Australian pool owners run solar and a heat pump together and let the heat pump fill the gaps.
Is a heat pump better than gas for heating a pool?
A heat pump is better than gas for almost every Australian pool, because it costs roughly four to six times less to run for the same heat. Gas only wins when you need the pool hot within a few hours after weeks of no use, such as at a holiday house.
How long does it take to heat a pool with a heat pump?
A correctly sized pool heat pump raises water temperature by about half a degree to one degree per hour of running, so a typical family pool takes one to two days to come up from cold. Once it reaches temperature it only idles to hold it, which is where the low running cost comes from.
Can you heat a pool with solar panels on the roof?
Yes, and there are two different methods. Solar pool heating uses black collector matting that your pool water flows through directly, while regular photovoltaic solar panels make electricity that can run a heat pump. Both work in Australia, and the photovoltaic plus heat pump combination gives you temperature control that collector matting cannot.
Do I need a pool cover if I have a pool heater?
Yes, a pool cover is worth having with every type of pool heater. Most heat escapes an open pool through evaporation off the surface overnight, so a cover keeps the heat you already paid for and lets you run a smaller heater for fewer hours.
Do pool heat pumps work in winter in Australia?
Pool heat pumps work through most Australian winters, though they lose efficiency as the air temperature drops. In Brisbane or Perth a well sized unit with a cover will hold a swimmable pool most of the year, while in Melbourne or Hobart you should expect a shorter season or size up.
Not sure which option suits your pool? Ask us
Tell us your pool volume, your postcode, whether the pool is covered and how long a season you want, and we will tell you which option makes sense and which model fits. No sales pitch, just the number.
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This guide is general information for Australian pool owners and is not a substitute for advice on your specific pool and site. Pool heat pumps are electrical appliances and must be connected by a licensed electrician. Gas heating work must be carried out by a licensed gas fitter. Confirm final sizing and installation requirements with us or your pool professional before you buy.