Pool heating attracts more confident misinformation than most household equipment, partly because the technology is genuinely counterintuitive and partly because there are four competing products and everyone is selling one of them.
Here are the claims that come up most often about a heat pump pool heater, and what is actually true.
"It cannot produce more energy than it uses"
Correct, and it does not.
This is the objection that sounds like a physics violation, and the scepticism is reasonable until you understand what the machine does.
A heat pump does not generate heat. It moves heat that already exists in the surrounding air into your pool water. The electricity you buy does not become the heat, it powers the fan and compressor that relocate it.
So a unit delivering four or five times more heat energy than the electricity it consumes is not creating energy. It is collecting diffuse, low grade warmth from a large volume of air, concentrating it, and depositing it in your pool.
No conservation law is troubled. It is a removals business, not a manufacturing one.
"They do not work in cold weather"
Partly true, and the way it is usually stated is misleading.
Output falls as ambient air temperature falls, because there is less available heat to collect. That much is correct and it is the fundamental trade off against gas.
What is not correct is the implication that they stop working in Australian conditions. Every unit has a minimum operating temperature, and in most of populated Australia that threshold is well below what winter delivers.
The real issue is specification. A unit sized against summer conditions will disappoint in July. A unit sized against genuinely cool ambient conditions, paired with a cover, will hold temperature.
The honest version: they work in cold weather at reduced output, and whether that is enough depends entirely on whether anyone accounted for it at sizing.
"They are slow, so they are not really practical"
True on the first half, misleading on the second.
A heat pump is slow from cold. A pool is an enormous mass of water and moving heat into it gradually takes time. If your requirement is a warm pool by Saturday having decided on Friday, this is the wrong technology and gas is genuinely better.
But that is not how most people use a pool. Most households want the water to be reliably right when they feel like swimming, which means holding a temperature rather than sprinting to one. Heat pumps are extremely good at holding.
The honest version: slow to arrive, cheap to stay. Match that to your actual pattern rather than your imagined one.
"Inverter means it is efficient"
Not necessarily, and this is the claim most worth interrogating.
The word covers at least three technologies:
On off units have one speed, maximum. They overshoot the setpoint, stop, drift down, and restart.
Stepped inverters have a handful of fixed speeds and cycle between them.
Full inverters vary compressor speed continuously across the range.
The reason it matters is counterintuitive: heat pumps are most efficient running slowly. At reduced compressor speed the refrigerant spends longer in contact with the heat exchangers, so you extract more heat per unit of electricity at part load than at full output.
Since holding a pool at temperature is a low demand job most of the time, a unit that can sit at low output spends most of its life in its efficient band. One that only has full power cannot.
The honest version: ask whether compressor speed is continuously variable or stepped. See the Evo Force-i Pro.
"A bigger unit will heat it faster and better"
Half true and it leads people astray.
A larger unit does have more output. It also costs more, and with on off technology an oversized unit short cycles, starting and stopping repeatedly, which is inefficient and hard on a compressor.
More importantly, oversizing does not fix the actual problem in most disappointing installations, which is heat loss rather than heat input. A pool losing heat rapidly overnight because it is uncovered will not be rescued by a bigger machine.
The honest version: correct sizing beats maximum sizing, and a cover beats both.
"The running cost figures are marketing"
Sometimes, and the way to tell is specific.
Efficiency figures are real but enormously condition dependent. A peak coefficient of performance is measured at the machine's single most favourable operating point, which bears little relationship to a cool April morning.
The tell is whether conditions are stated. A single number with no conditions is not useful. A performance curve across a range of ambient temperatures is.
The honest version: the technology genuinely multiplies energy. The specific number quoted may be measured somewhere you will never operate.
"You have to switch it off to save money"
Backwards, and it is the most common operating error.
A pool is a large thermal mass. Reheating from cold takes substantial energy. Holding a temperature costs comparatively little because you are only replacing ongoing losses.
Households that switch off between swims and reheat repeatedly spend more than households that set a temperature and leave it.
The honest version: hold the setpoint. Drop it for extended absences rather than switching off entirely.
"They are noisy"
There is a fan and a compressor, so there is sound. Whether it is a problem depends on placement and technology.
A full inverter running gently at part load is considerably quieter than a fixed speed unit that is either at full noise or silent. Positioning matters more than the decibel figure: under a bedroom window is a decision you will revisit regardless of the unit.
The honest version: not silent, generally unobtrusive when correctly placed, and quieter at part load.
Frequently asked questions
Can a heat pump cool my pool?
Reversible models can, which in tropical and subtropical Australia is a genuine feature rather than a novelty.
Do they work at night?
Yes. Unlike solar they depend on ambient air temperature, not sunlight, which is one of their main advantages.
How long do they last?
Long term equipment given clear airflow and balanced water chemistry. Units that run steadily at part load cycle less, which reduces mechanical wear.
Are they better than gas?
Different. Gas wins on speed and weather independence. Heat pumps win decisively on cost per hour of swimming across a long season.
What is the single biggest factor in whether I am happy with one?
Correct sizing, followed by using a cover.
Judge it on your own pattern
Most disagreement about heat pumps comes from people comparing them against a use case they were never designed for.
Browse the full pool heater range, or request a free personalised pool heat report.
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