Heat pump eligibility questions come in many forms: which heat pumps qualify, whether every heat pump does, whether big ones count and what about zone 5. They all come back to four tests.
The four tests
- On the register. The exact model must be listed on the Clean Energy Regulator’s register of solar water heaters. A near-identical model with a different code is not eligible by association.
- Under the size limit. The regulator states that air source heat pumps must be under 425 litres to qualify for STCs.
- Installed correctly. The unit must be new equipment installed by someone who meets state or territory licensing requirements, and the STCs must be created within 12 months of the install.
- Right install type. A new installation or replacement is evidenced differently. See new, replacement or additional.
Is every heat pump eligible?
No. Reverse-cycle air conditioners are not hot water heat pumps. Second-hand units and products not listed on the register do not qualify. Even within a brand, some models will be registered and others not. See heat pump rebate eligibility.
Large heat pumps and 425 litres
A heat pump over 425 litres, or a commercial heat pump, generally does not qualify for federal STCs. This catches people who size up for a larger household. Some state programs have different rules, including Victorian and NSW activities, so a large unit may still earn state certificates. The right approach is to check the register and the state scheme, not assume. Details of the state side are in heat pump VEECs in Victoria and NSW heat pump rebates.
Hot water heat pumps in zone 5
Zone 5 is one of five heat pump postcode zones. Eligibility does not depend on zone. A registered, under-425-litre unit installed by an eligible installer in zone 5 earns STCs, calculated from the zone 5 figure on the register. See heat pump STCs by zone.
Does the brand matter?
Only through the model. Each model is registered individually. The question to ask is whether this model number appears on the register, not whether the brand is well known. How to check is in how to check hot water STC eligibility.
Timing
Entitlements also fall each January. At roughly $38 to $40 per STC at the time of writing, even an eligible unit earns less in 2027 than in 2026. See do heat pump STCs reduce every year.
What this means for you
Homeowners should ask the installer for the register entry, not just a brand promise. Installers should check eligibility at quote and again at install, and keep the plate and serial evidence. The hot water STCs pillar and hot water checklist cover the claim, and pricing shows the settlement rate.