Record resident numbers, shower patterns, bath use, appliance connections and likely changes. Ask for the model's rated hot water delivery, not only its tank volume.
Match capacity and timing to household demand
A suitable hot water system must cover the household's peak demand, climate and available energy supply. Compare the full installed scope and likely operating schedule, not the tank price alone.
Prepare the evidence
Document demand and site constraints
Identify rooftop solar, controlled-load wiring, tariff windows and when hot water is normally used. A timer may improve solar self-use only if recovery and storage remain adequate.
Check cold-weather operation, frost suitability, airflow, drainage and compressor noise at the proposed location, especially near bedrooms and neighbours.
Compare technologies
Understand where each option can differ
Heat pump and solar hot water
Heat pumps transfer heat from surrounding air into stored water. Australian Government guidance says they can use about 30% of the energy of a conventional electric hot water system, but climate, model performance, backup heating and schedules matter.
- Confirm integrated or split configuration
- Check compressor sound and cold-climate limits
- Ask when the resistive booster operates
- Check the exact model against current incentive registers
Electric storage and gas systems
Storage systems keep a tank hot, while continuous-flow systems heat water on demand. Compare standing losses, tariff access, electrical capacity, gas fixed charges, venting and whether changing systems affects other appliances.
- Confirm tank delivery and recovery time
- Check controlled-load or three-phase requirements
- Include decommissioning and connection work
- Plan a temporary service if replacement is urgent
Written quote checklist
Make installation and incentive claims auditable
- Exact marketed and registered model numbers
- Tank volume and rated hot water delivery
- Expected annual energy under the relevant climate zone
- Normal, boost and low-temperature operating modes
- Timer, controller and rooftop solar integration
- Electrical, plumbing, drainage and structural work
- Removal, disposal and temporary hot water arrangements
- Product, tank, compressor and workmanship warranties
There is no mandatory Energy Rating Label for heat pump water heaters yet.
Compare written performance data and warranty terms carefully. A 2026 government decision supports future minimum performance standards, with labelling expected through a later implementation stage.
Certificates and rebates
Verify the exact model before installation
Eligible solar water heaters and air source heat pumps may receive Small-scale Technology Certificates. The exact model must be on the Clean Energy Regulator register and installed as listed. Certificate values vary by model, postcode zone and the remaining deeming period.
State and territory rebates can change and may have separate product, property, installer and replacement rules. Check the current government directory and administering program before signing.