How we rate heat pump hot water.
A heat pump water heater should save as much energy as possible, keep working on frosty mornings, last, and not disturb you or the neighbours. We start from the government's own savings figures for every model, then add the warranty, cold-weather limit, noise and refrigerant from the manufacturer's documents.
Method version 2.2, 7 October 2026. Product data checked 16 September 2026.
- series on the approved list
- 33
- home series ranked
- 30
- approved models covered
- 301
- criteria, each with a published rule
- 5
What makes up the score.
Each criterion turns one published value into a score from 0 to 10. The weights add up to 100%.
Energy savings (official)
30%STCs are calculated by the government from tested performance under the Australian Standard: the more energy a heat pump saves against an electric tank, the more it earns. It's the one efficiency figure every brand is measured the same way on.
The rule
STCs for a Zone 3 installation on the Clean Energy Regulator register, best model in the series: 26 scores 0, 34 scores 10.
- Lowest
- 28
- Typical
- 32
- Highest
- 34
Across the 30 ranked home series that state it.
Warranty
25%Tanks and heat pump units are covered for different terms. Both matter: a tank leak or a dead compressor is the expensive failure.
The rule
Average of the cylinder and the refrigeration-system parts warranty, in years: 3 scores 0, 10 or more scores 10.
- Lowest
- 5
- Typical
- 6
- Highest
- 10
Across the 30 ranked home series that state it.
Cold-weather operation
15%Below its limit, a heat pump hands over to the electric element and costs as much to run as an old tank.
The rule
Lowest outdoor temperature the heat pump runs at without the element: 0°C scores 0, -10°C or colder scores 10.
- Lowest
- -15
- Typical
- -7
- Highest
- -5
Across the 29 ranked home series that state it.
Quietness
15%Heat pumps often sit near bedrooms or a neighbour's window.
The rule
Sound pressure at 1 metre: 55 dB(A) scores 0, 37 dB(A) scores 10. Figures quoted at 2 metres have 6 dB added.
- Lowest
- 37
- Typical
- 47
- Highest
- 54
Across the 29 ranked home series that state it.
Refrigerant
15%Natural refrigerants have almost no climate impact and are what new systems are moving to; older synthetic ones are being phased down.
The rule
Natural refrigerants R744 (CO2) and R290 score 10; R513a 5; R32 4; R134a 2.
How we read the documents.
The details that decide whether a number is fair to compare.
- Energy savings (official)
- Every heat pump on the Clean Energy Regulator register is modelled under the Australian Standard, and earns small-scale technology certificates (STCs) in proportion to the energy it saves against an electric tank. We use the Zone 3 figure for the best model in each series. Unlike manufacturers' COP figures, every brand is measured the same way.
- Cold-weather operation
- The lowest outdoor temperature at which the heat pump itself runs, as printed on the datasheet. Below it, the electric element takes over and running costs jump.
- Noise
- Sound pressure at 1 metre. Where a maker quotes 2 metres, we add 6 dB so every brand is compared at the same distance.
- Warranty
- The average of the cylinder and the refrigeration-system parts warranty. Labour cover and pro-rata years are shown but not scored.
Before anything is scored
- Currently on the Clean Energy Regulator register of air source heat pumps, so it earns STCs
- Manufacturer datasheet or brochure on file for the series
Not in the score, and why
- Manufacturer COP figures, because brands test them at different conditions; we show them, but score the government-modelled savings instead
- Price and installation
- Recovery rate and tank size, which depend on your household rather than the product's quality
A worked example.
Reclaim Energy CO2 Split (REHP-CO2-160GL / REHP-CO2-160GL-V2 / REHP-CO2-160SS-WIL …), exactly as the site scores it. Each value is from its documents, the score applies the rule, and points are score × weight.
- Energy savings (official)327.5 × 30%2.25
- Warranty1010.0 × 25%2.50
- Cold-weather operation-1010.0 × 15%1.50
- Quietness3710.0 × 15%1.50
- RefrigerantR74410.0 × 15%1.50
- EnergyUpgrade Score9.3
How heat pump hot water brands are rated.
A brand rating adds what a datasheet can't show: what owners say, how the brand's products have held up, what installers and the market say, and whether you can reach it in Australia.
Product scores
40%Average datasheet score of the brand's two best home series in the category, the ones an installer would actually quote. Older ranges still on the approved list don't drag a brand down.
Owner reviews
20%What owners say across the brand's products in this category: SolarQuotes owner reviews for panels, inverters and batteries, and ProductReview.com.au plus SolarQuotes for heat pumps. Reviews are averaged by count, and every brand is pulled towards 4.0 stars as if it had 30 more reviews at that level, so a handful of perfect reviews can't beat thousands of good ones. 3.0 stars or lower scores 0, 5.0 scores 10. Listings for a range the brand no longer sells are shown but not counted, and a listing about the company in general counts half.
Track record
15%Panels: Kiwa PVEL Top Performer status, 2 points for each of the 2024, 2025 and 2026 scorecards plus up to 4 for total editions (10 or more scores 4). Inverters and batteries: up to 7 points for years selling in Australia (8 or more scores 7) and 3 for a stock-exchange listing. Heat pumps, which should last 10 to 15 years: up to 7 points for years trading in Australia (20 or more scores 7) and 3 for a listing. ACCC recalls of that kind of product take points off: 3 for one covering a range we list, 2 for another, doubled when the brand offers no remedy. A brand in liquidation scores 0.
Installer and market standing
15%Average of two independent results, each using the better of this year's result and last year's (last year's counts 80%). The SolarQuotes Installers' Choice vote: 1st scores 10, 2nd 8, 3rd 7, 4th or 5th 6. SunWiz awards from Clean Energy Regulator installation data: No. 1 for homes scores 10, No. 1 in another segment or 2nd–3rd 8, top 5 or fastest growing 6. For panels, BloombergNEF Tier 1 status scores 6 when there's no SunWiz award. For heat pumps, which have no installation-data award, the second result is popularity from the number of owner reviews: 10 reviews scores 2, 100 scores 5, 1,000 scores 8.
Australian support
10%Published Australian office 4 points, local support phone 3, local service email 2, more than one office 1.
What the score bands mean
- 9.0Excellent8.5 and above
- 8.0Very good7.5 to 8.4
- 7.0Good6.5 to 7.4
- 5.0FairBelow 6.5
Data confidence
- High
- Australian datasheet, verified against the approved list, states at least 85% of what we weigh, and every scored value appears in the PDF.
- Medium
- A global edition of the datasheet, a small gap in the data, or a value we couldn't find printed in the sheet we hold.
- Low
- The datasheet doesn't clearly match every model in the series, or leaves out more than a third of what we weigh. Low-confidence series can't be a pick.
Questions about the heat pump method.
Why not use the manufacturer's COP?
Brands test COP at different air and water temperatures, so the numbers aren't comparable. The STC figure on the federal register is modelled the same way for every model.
Why does refrigerant matter?
Natural refrigerants such as R290 and CO2 have a tiny climate impact and usually perform better in the cold than older R134a units, which are being phased down.
Which brands are rated?
We rate 16 heat pump brands commonly quoted to Australian homes, using every model of theirs that is currently eligible for STCs and still sold. A brand in liquidation is listed for the record but not ranked.
More on how we rate
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