This is the question that decides which heater most people should buy, because the upfront price is only half the story. A gas heater is cheaper to install but expensive to run. A heat pump is dearer to install but cheap to run. Over a few seasons the running cost usually matters more than the install gap. This page breaks down exactly why the heat pump wins on running cost, where gas still earns its place, and how much a pool blanket changes the maths. For install pricing see heat pump pool heater cost and gas pool heater install cost.
The short answer
The heat pump is cheaper to run, and it is not close. Across a Gold Coast swim season a heat pump typically costs a fraction of what a gas heater costs to run for the same pool kept at the same temperature. The reason comes down to one idea, a heat pump moves heat, a gas heater makes it.
Why the heat pump is so much cheaper
A gas heater burns fuel and turns that fuel energy directly into heat. It is efficient at doing that, but you only ever get out what you put in, you are paying for every unit of heat with a unit of burned gas.
A heat pump does something cleverer. It runs a refrigerant circuit, the same idea as a reverse-cycle air conditioner, and uses a relatively small amount of electricity to harvest heat that already exists in the surrounding air and pump it into the pool. For every unit of electricity it draws, it delivers several units of heat into the water, typically in the range of four to six times more than you would get by turning that same electricity straight into heat with an element. You are not paying for the heat itself, only for the electricity to move it. That multiplier is the entire reason the running cost is low.
Running cost across a Gold Coast season
Exact dollars depend on your pool size, how warm you keep it, how long your season is, whether you run a blanket, and your energy rates, so get these as a guide rather than a promise. For a typical residential Gold Coast pool maintained through the swim season:
- Heat pump: the cheapest to run by a clear margin, often only a couple of hundred dollars in electricity across the season, and far less again if you run a blanket or feed it from solar PV during the day
- Gas heater on natural gas: the most expensive to run, typically several hundred dollars across a season and more if you heat hard or push into the colder weeks
- Gas heater on LPG: dearer again than natural gas, because LPG costs more per unit of energy, this hits acreage and hinterland homes without mains gas
- Solar pool heating: cheapest of all to run, essentially just the cost of running the pump, but the heat is sun-dependent rather than on demand
The gap between the heat pump and gas widens the more you use the pool. For an occasional weekend heat-up a couple of times a year the running cost difference is small in absolute dollars. For a household that keeps the pool warm all season, the heat pump can save a meaningful amount every year, which is what pays back its higher install cost.
So why would anyone choose gas?
Because running cost is not the only thing that matters. Gas has two genuine advantages a heat pump cannot match.
Speed
Gas heats fast. A correctly sized gas heater can lift a pool to swim temperature in a day or so from cold. A heat pump moves heat gently and steadily, so it takes several days to do the same job from a cold start. If you want to decide on Friday that the pool will be warm for the weekend, gas delivers and a heat pump does not.
Weather independence
Gas does not care what the air temperature is, it burns the same on a cold, still winter morning as on a warm afternoon. A heat pump leans on the warmth in the air, so on the coldest, stillest days it works harder and slower. Across most of the Gold Coast season that is a minor effect, but it is real in deep winter.
So the pattern is clear. Gas suits stop-start, on-demand use, the family that heats for the school holidays and wants it hot now. The heat pump suits maintained, regular use, the household swimming through the season that keeps the pool at temperature and wants the lowest possible running cost. Pick the heater to match how you actually use the pool, not the headline price.
The pool blanket is the real lever
Whichever heater you choose, the single biggest thing you can do to cut running cost is fit a pool blanket. Most of a pool's heat escapes off the surface overnight through evaporation, and a blanket shuts that down. It cuts the running cost of every heating type substantially, often enough to roughly halve what you spend keeping the pool warm. It also lets you run a smaller, cheaper heater for the same result. We recommend a blanket as standard alongside any heater. A heater with no blanket, gas or heat pump, is the most expensive way to keep a pool warm, because it spends all night fighting heat loss you could have prevented for the cost of a cover.
Solar feeds the heat pump for almost nothing
If you have rooftop solar PV, the running-cost case for a heat pump gets stronger again. Run the heat pump through the middle of the day on the power your own panels are generating and you are heating the pool on electricity that would otherwise have exported for a low feed-in tariff. For a lot of Gold Coast homes with solar, that drops the heat pump's effective running cost close to zero in the sunny months. Gas cannot do this, it burns the same fuel whether the sun is out or not.
Lifetime cost, the way to actually compare them
The right way to compare is not install price and not running cost alone, it is both together over the years you will own the heater. A gas heater starts cheaper but the higher running cost accumulates every season. A heat pump starts dearer but the low running cost means the lines cross after a few seasons of regular use, and from there the heat pump is ahead and keeps pulling away. If you swim a lot, the heat pump usually wins on total cost. If you heat rarely, the install saving on gas may never get overtaken because you are not running it enough for the running-cost gap to matter. How heavily you use the pool is the deciding number.
What about solar as the cheapest runner?
Solar pool heating is the cheapest of all to run because the sun is free, the only running cost is the pump pushing water up to the roof collector. The trade-off is that it heats only when the sun is out and it is a season-extender rather than an on-demand or all-weather heater. Plenty of Gold Coast homes pair solar with a small heat pump or gas heater so they get near-free heating most of the time and a top-up when the weather turns. We cover the detail on the is solar pool heating worth it page.
Our honest take for the Gold Coast
For most households that genuinely use the pool through the season, the heat pump is the right answer on running cost, and a blanket plus a properly sized unit is the combination we fit most. For occasional, fast, heat-it-now use, gas still earns its place despite the higher running cost. For the lowest possible running cost and a longer comfortable season, solar is hard to beat if you can live with sun-dependence. We are happy to model all three against your actual pool and usage so you are choosing on real numbers, not a sales pitch, and our gas fitting team installs all of them. For the wider picture read our guide to pool heating on the Gold Coast, and when you want a quote, get in touch.