The best heat pump hot water system in Australia is the one that fits your household’s hot water use, your climate and your noise and space constraints, that appears on the regulator’s eligible list so it earns incentives, and that comes with a warranty and installer you trust. Rankings of brands age quickly and rarely account for your home. A checklist works better, and this guide gives you one.
We are not ranking brands here. We run a certificate trading business, not a product review site, and the models and prices on offer change faster than any article can keep up. What we can do is show you what to measure, how to size the system, and how incentives affect the choice, so that when you compare two quotes you know which numbers matter.
Start with eligibility
A heat pump earns small-scale technology certificates only if the model is on the Clean Energy Regulator’s list of eligible products and installed according to the rules. In Victoria, VEEC eligibility is set by the Essential Services Commission’s activity requirements. Before you fall for a model, check both.
Three questions to ask every installer:
- Is this exact model, including variant, on the eligible lists today?
- How many STCs (and VEECs, if you are in Victoria) will it create for my address?
- Are those already deducted in the quote?
Our heat pump STC explainer and the eligibility answer set out the rules.
Size it properly
An undersized tank runs out of hot water; an oversized one costs more and can lose heat. Size from usage.
| Household | Typical starting point | Notes |
|---|---|---|
| 1 to 2 people | Around 160 to 250 L | Lower if usage is light |
| 3 to 4 people | Around 250 to 300 L | Check shower and bath habits |
| 5 or more | 300 L and above, or two units | Consider recovery rate |
These are starting points, not rules. Ask the installer to size from your occupants, bathroom count, appliances and any spa or large bath. Ask how the unit recovers after heavy use, and whether a boost element is fitted and when it runs.
The specifications that matter
Efficiency. Look for the rated annual energy consumption or coefficient of performance on the product sheet and compare like with like for your climate zone.
Cold-climate performance. If you live where winter nights are cold, check the operating range and the efficiency at low temperatures.
Noise. Compressors make noise. Check the sound rating and where the outdoor part will sit relative to bedrooms and neighbours.
Tank construction. Materials and anode protection affect life, particularly in areas with aggressive water. Ask about local water quality.
Controls. Can it be timed to run when your solar is producing or when your tariff is cheapest? Some models have smart controls and compatibility with home energy systems.
Refrigerant. Newer models use refrigerants with a lower global warming impact; this may matter for future servicing.
Warranty. Ask separately for the tank, the compressor and labour, and what voids them.
Service. Where will a technician come from, and how quickly?
Compare quotes on net price and total cost
Take a hypothetical case. Quote A is for a $3,900 unit with incentives of $1,400 already deducted, leaving $2,500. Quote B is a $3,200 unit with $600 of incentives deducted, leaving $2,600. A is $100 cheaper after incentives, but if its warranty is shorter, its noise higher, or it needs a more expensive electrical upgrade, B could cost less over its life. The figures are illustrations. The method is to line up the incentives, the net price and the running cost.
Use the energy method from our heat pump versus solar hot water guide: take the annual consumption on the product sheet, compare with your existing system, and multiply by your tariff.
Installer matters as much as the product
A good product installed badly is a bad product. Check that the installer holds the right licences, that they will take the evidence photos required for the claim, and that they can explain who lodges the claim and when. If they are working under a Victorian accredited provider for VEECs, ask who that is. Our VEEC guide for households lists the questions.
Red flags in a heat pump quote
- No model number. “Premium heat pump” is not a product.
- An incentive with no count. Ask for the number of STCs and how the dollar value was set.
- A deadline that expires tonight. Real incentives follow published dates, not a salesperson’s clock.
- A price that depends on you doing the paperwork. The installer should handle the claim or tell you clearly what you must sign.
- No mention of electrical work. Switchboard capacity, circuit changes and isolator placement can add cost. Ask for them in writing.
- Vague warranty language. “Full warranty” without years, parts and labour.
After the install
Keep the invoice, the model and serial numbers, the commissioning sheet and the installer’s details. Ask the installer to set the timer or controls and to show you how to adjust them. If you have rooftop solar, ask for the heat-up window to be set around midday. Check the first two or three bills against your estimate; if consumption is much higher than expected, the settings are the first place to look. A good installer will come back to fix a setting without charging.
Questions to ask at the quote stage
Ask how the installer arrived at the tank size and whether they measured or estimated your use. Ask whether the unit can be switched to run at set hours. Ask where the outdoor part will sit and what clearance it needs. Ask what happens to the old unit and whether disposal is in the price. Ask who services it, and what the call-out terms are after the labour warranty ends. Ask whether they have installed this model before and can show a recent job. A short, specific answer to each is a better sign than a polished brochure.
State-by-state incentive notes
- Victoria: VEECs, possibly Solar Victoria support (income-tested; cap $150,000 from 1 July 2026), plus STCs. See heat pump VEECs in Victoria.
- NSW: Energy Savings Scheme certificates may apply to some upgrades. See the NSW answer.
- Other states: federal STCs, plus whatever state or council program is current. Check official sites.
What to do next
- Write down your household size, climate and constraints.
- Shortlist models that are on the eligible list, and compare noise, efficiency and warranty.
- Get two or three quotes with STC count, other incentives and net price.
- Installers: read the hot water pillar, the checklist, how it works and pricing.