Pool Heating in Melbourne: Heat Pump vs Solar vs Gas
Melbourne has a famously short swimming season. Without heating, most backyard pools are only comfortable for a few months over summer, and even then a cool change can drop the water temperature overnight. The right pool heating changes that, stretching your season from spring through to autumn, or even all year. Here's how heat pumps, solar and gas compare, so you can choose the right one before you build or upgrade.
Heat Pump, Solar or Gas: How They Compare
There are three main ways to heat a pool. Each works differently, costs a different amount to run and suits a different kind of pool owner.
Heat Pumps
A heat pump works like a reverse air conditioner. It draws warmth from the surrounding air and transfers it into the pool water. Because it moves heat rather than creating it, a good heat pump can deliver several units of heat for every unit of electricity it uses.
That makes heat pumps the most popular all-round choice in Melbourne. They hold a steady temperature, work regardless of cloud cover and can extend the season well into autumn. Newer inverter models run quietly and adjust their output to what the pool needs. They're slower to heat than gas, so they're best left running to maintain a temperature rather than switched on for a quick swim.
Solar Heating
Solar heating pumps pool water through collectors on your roof, where the sun warms it before it returns to the pool. Once installed, it costs almost nothing to run beyond the pool pump you already have.
The catch in Melbourne is that solar depends on the weather. It works well from late spring to early autumn, but struggles on cloudy days and through winter. It also needs enough north-facing roof space. Solar suits owners who mainly want a longer, warmer summer season at the lowest running cost.
Gas Heaters
A gas heater burns natural gas or LPG to heat the water quickly, often raising the temperature by a degree or two an hour. That speed is its main advantage: you can heat the pool for the weekend or a party without running it all week.
The downside is running cost. Gas is generally the most expensive way to keep a pool warm over a whole season, especially with LPG. Many Melbourne owners now use gas for spas, or as a top-up alongside a heat pump or solar, rather than as the main heater.
| Factor | Heat Pump | Solar | Gas |
|---|---|---|---|
| Running Cost | Low to moderate | Very low | High |
| Heating Speed | Slow and steady | Slow, weather dependent | Fast |
| Cloudy or Cold Days | Works well | Limited | Works well |
| Best For | Long seasons, steady temperature | Extending summer cheaply | Spas and quick heating |
Which Heating Suits Your Pool?
The best option depends on how you plan to use your pool.
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You want to swim from October to April. A heat pump is usually the best fit. It keeps the water comfortable through Melbourne's cooler spring and autumn days.
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You mostly want a warmer summer at the lowest cost. Solar heating is hard to beat on running costs, as long as you have suitable roof space.
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You want to swim year-round. Pair a heat pump with solar, or a heat pump with a good pool cover. Solar does the heavy lifting on sunny days and the heat pump covers the rest.
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You have a spa or swim spa. Gas makes sense here because the water volume is smaller and you often want heat quickly.
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You already have rooftop solar panels. Running a heat pump during the day can use your own solar power and bring running costs down further.
Plan Heating at Build Time
When Sienna Pools builds a concrete pool or installs a fibreglass pool, the heating, pump and plumbing can be sized and positioned together, which is simpler and cheaper than retrofitting later. We also upgrade existing pools with energy-efficient heat pumps, solar and gas heating.
How to Keep Heating Costs Down
Whichever heater you choose, how you run it makes a big difference to your bills.
Use a Pool Cover
Most of a pool's heat escapes from the surface, especially overnight. A cover is the single most effective way to hold the heat in for any heater.
Pick a Sensible Temperature
Around 26 to 28 degrees is comfortable for most families. Every extra degree costs more to maintain.
Heat for the Season
Unless you really will swim in July, running the heater from spring to autumn keeps costs in check.
Run a Heat Pump by Day
Air temperatures are higher, so it works more efficiently, and it can use your rooftop solar power if you have it.
Choose Efficient Equipment
A modern inverter heat pump and a variable speed pump use far less power than older equipment.
Get It Sized Properly
An undersized heater runs constantly and struggles to keep up. Your builder should size it to your pool's volume and how you use it.
Get More Swimming Out of Your Melbourne Pool
For most Melbourne homes, a heat pump with a pool cover is the best balance of comfort and running cost, with solar a great addition if you have the roof space.
Sienna Pools is a family business run by brothers Steve and Patrick, with over 30 years of combined experience building concrete and fibreglass pools across Melbourne. Whether you're planning a new pool or upgrading the heating on your existing one, get in touch for honest advice and a free quote.
Frequently Asked Questions
Ready to Extend Your Swimming Season?
Book a free consultation with Steve and Patrick to talk through heating for a new or existing pool, or see how we work on our building process page.
