- shane@sydneypoolandgas.com.au
- 0422 302 722
- Mon–Sat: 7AM–6PM
- NSW Licensed Gas Fitters Licence No. 498373C
Gas, heat pump or solar — what each one costs to run, how long each takes to warm a pool, and how to work the number out for your own pool. The figures below use published Sydney energy rates, and you can put your own in.
Heating cost comes down to three things: how much water you are heating, how many degrees you are lifting it, and what you pay for gas or electricity. The rest is arithmetic.
Set your pool size and how warm you want the water. The figures update as you type.
Length × width × average depth, in metres, × 1,000.
A Sydney pool sits around 19–21°C in early spring.
28°C is a comfortable swimming temperature.
| Gas heater | Heat pump | Solar | |
|---|---|---|---|
| Cost to warm it upOnce, from where it is now to the temperature you want | — | — | $0Sunshine is free — you pay only for the pump. |
| How long that takesRunning the heater continuously | —On a 200 MJ/h heater. | — | WeeksSolar lifts the temperature a degree or two at a time, on sunny days. |
| Then, to hold it therePer week, replacing the heat the pool loses | — | — | WeatherSolar holds temperature well in summer and not at all in a cold week. |
| Every extra degreeWhat one more degree costs you | — | — | $0 |
Both are printed on your bill. Gas is charged per megajoule, electricity per kilowatt-hour.
There is no single winner. Each one does one thing well and one thing badly, and which suits you depends on how you actually use the pool.
Gas heats fast. A 200 MJ/h heater — a common size for an average pool — lifts 40,000 litres by 8°C in about eight hours. You can decide on Friday that you want to swim on Saturday. It also costs the most per degree, so it suits a pool you heat when you want it rather than one you keep warm all the time.
A heat pump costs the least to run. In mild weather it delivers about five units of heat for every unit of electricity it uses, which puts it a bit over a third of gas per degree. It is slow: the same pool takes a couple of days rather than an afternoon. It suits a pool you want warm right through the season.
Solar costs almost nothing to run, because once it is installed the only thing drawing power is the pump. It heats when the sun is on the collectors, so it lengthens your swimming season rather than setting your temperature.
The two questions that decide it are how big the pool is, and whether you have a cover. A cover changes the running cost more than the choice of heater does — on the figures above it cuts the cost of holding an average pool at temperature by roughly two thirds. And if you already have solar panels on the roof, a heat pump is the one to look at, because it runs on electricity you are already making.
If the heater you have is gas, servicing and repairs are licensed gas work — here is what a service covers and what it costs.
How much water you have. Cost scales almost exactly with volume. Warming a 20,000-litre pool by 8°C on gas costs about $35; the same job on a 60,000-litre pool costs about $105. Nothing else on this page moves the number as much.
Whether you use a cover. A pool loses most of its heat by evaporation off the surface, and a cover stops most of that. On an average pool it cuts the cost of holding temperature by roughly two thirds — about $2,000 over a six-month season on gas. A cover is the cheapest thing you can do to a heated pool, and it works the same whichever heater you own.
The temperature you pick. Every degree costs about $8.54 to put into an average pool on gas, or about $3.26 on a heat pump. It then costs more again to hold, because the warmer the water is, the faster it loses heat to the air. Dropping a target from 30°C to 28°C makes a bigger difference to a bill than most people expect.
How long you run the season. Heating from September to April costs roughly twice heating over summer alone. This is where solar and heat pumps earn their money back, and where gas hurts most.
A gas pool heater burns gas to heat water directly, which is why it is quick. Residential units are sized in megajoules per hour, usually somewhere between 150 and 400 MJ/h, and a 200 MJ/h unit will lift an average pool 8°C in about eight hours.
What it is good at. Heating on demand. If you want the pool warm for the weekend and it is cold on Thursday, gas is the only one of the three that can do it. It also does not care how cold the air is, so it works in the middle of winter when a heat pump is struggling.
The honest downsides. It is the most expensive of the three to run. Holding an average pool at 28°C costs roughly $520 a month uncovered, or about $180 a month with a cover on. It needs an adequate gas supply at the equipment, and servicing and repairs are licensed gas work, so it is not a job for a general handyman.
Sydney Pool and Gas Heating is Shane and the team, and Shane is on the tools himself. Gas pool heater servicing and repairs are licensed gas work, and we hold that licence (NSW 498373C). We service and repair all major gas pool heater brands — Astral, Hayward, Hurlcon and Pentair among them — and install new units including Raypak and Rheem. Here is what a service covers and what it costs.
A pool heat pump does not make heat, it moves it — pulling warmth out of the air and putting it into the water, which is a fridge working in reverse. Moving heat is far cheaper than making it, and that is the whole story of its running cost: holding an average pool at 28°C comes out around $200 a month uncovered, or about $70 with a cover on.
Where a heat pump loses. Cold air. It is pulling heat out of the atmosphere, so the colder the morning the less there is to pull and the harder it works — the same warm-up that costs about $25 in mild weather costs closer to $35 in the cold, and takes longer to get there. It slows down precisely when you most want it. It is a heater for a pool you keep warm, not one you bring up from cold on a whim.
Solar runs pool water up through collectors on the roof and back again warmed, so the only power drawn is the pump you already run. What it asks for instead is roof area facing the right way, and patience — on a cold, overcast week it does nothing at all, and there is no dial to turn up. That is exactly why it pairs well with gas: solar carries the ordinary weeks, and gas covers the cold snap when you actually want to swim.
If you already have solar panels on the roof, a heat pump is the one to look at — it runs on electricity you are already making, which is the cheapest power you will ever put into a pool.
We work on both, so the choice is genuinely yours. We install, service and repair all major pool heat pump brands as well as gas heaters, with EvoHeat and Raypak among the inverter units we fit. If you are weighing one against the other for your own pool, it is worth a call either way: the two questions that decide it are the same ones we would ask about a gas heater — how big is the pool, and is there a cover on it?
This is the bill most people never look at. A typical 1.1 kW single-speed pool pump left running 24 hours a day costs about $280 a month in electricity. Run the same pump on a timer for eight hours a day and it costs about $95.
That is about $185 a month, for a change that takes two minutes at the timer. Most residential pools only need to turn their water over once a day, so the long hours are usually habit rather than need — though a green or heavily used pool is a different case, and a pump that is short-cycling or running hot is telling you something.
It is worth knowing before you blame the heater. If your summer electricity bill jumped and the heating was off, the pump is the first place to look.
“Shane provides a punctual professional and very reasonably priced service. I would highly recommend him for any gas related issues!” — Scott Murray
“Thank you for the very good service and professionalism at installing a pool heat pump.” — Phil Clave
What does it cost to run a pool heater each month?
For an average 40,000-litre Sydney pool held at 28°C: gas is roughly $180 a month with a cover and about $520 without one. A heat pump is roughly $70 a month covered and about $200 uncovered. Solar costs close to nothing to run. These are running costs at published Sydney energy rates, not the cost of buying or installing equipment.
Is it cheaper to leave a pool heater on all the time?
It depends which heater you have, and this is where the two part company. With gas, no — heat it when you are going to swim, because holding temperature costs money every single day. With a heat pump it is usually the opposite: it recovers slowly, so keeping it at temperature under a cover generally beats letting it drop and hauling it back up.
What is the cheapest way to heat a pool?
Solar is cheapest to run, then a heat pump, then gas. But the cheapest thing you can do to any heated pool is put a cover on it — that is roughly two thirds off the cost of holding temperature, whichever heater you own, and about $2,000 over a six-month season on gas.
What are the downsides of a gas pool heater?
Running cost, mainly — about $8.54 a degree on an average pool against about $3.26 on a heat pump. It also needs an adequate gas supply, and servicing and repairs have to be done by a licensed gas fitter. What you get for that is speed: gas will have a pool swimmable in hours rather than days, in any weather.
How much does it cost to run a pool pump 24 hours a day?
A typical 1.1 kW pump costs about $280 a month running continuously, against about $95 on an eight-hour timer. For most residential pools the timer is enough, and the difference is larger than a lot of people expect.
How long does it take to heat a pool?
To lift an average pool 8°C: about eight hours on a 200 MJ/h gas heater, a couple of days of running on a 20 kW heat pump, and weeks on solar, which adds a degree or two at a time on sunny days. A cover shortens all three, because the pool stops losing what you just put in.
Do these numbers include installing the heater?
No. Everything on this page is running cost — the gas or electricity the heater uses. What a heater costs to buy and install depends on the unit and the site, and is quoted separately.
We install, service and repair gas pool heaters and pool heat pumps across Sydney. Call 0422 302 722.
