Gridly
18 Systems Ranked · Updated 2026
Best Heat Pump Hot Water for Off-Peak Tariff (Australia 2026)
Using controlled load or time-of-use electricity rates. We ranked every heat pump hot water system in Australia for this specific use case, weighing tank capacity and recovery as the primary factor.
Why Off-Peak Tariff Changes the Choice
Binding Constraint
Tank sizing for overnight heating, the tank must be large enough to heat fully during off-peak hours and supply the household all day
On controlled load or off-peak tariffs (as low as $0.10-0.18/kWh), the heat pump runs during off-peak windows (typically 10pm-7am). The tank must be sized to store enough hot water for the full day. Larger tanks (300L+) provide more buffer. A timer is essential to restrict operation to off-peak hours.
Controlled load tariffs are the cheapest electricity available in Australia, often 50–60% less than standard rates. Running a heat pump on a $0.14/kWh off-peak rate with a COP of 4.5 costs approximately $80–$120 per year for hot water — less than a dollar a day for the whole household. The trade-off is that the heat pump can only run during off-peak hours (typically 10pm–7am), so the tank must be large enough to store a full day's hot water from a single heating cycle.
Our Top Picks for Off-Peak Tariff
Ecogenica
R 290
$2,600
Why it wins: 290L tank stores a full day's hot water from a single off-peak heating cycle. Annual running cost approximately $107 on a $0.14/kWh controlled load tariff.
iStore
270L
$2,790
Why it is good value: At $2,790, it is $-190 less than our top pick while still meeting all the key criteria for off-peak tariff. COP of 4.8 keeps running costs low. Eligible for state rebates to reduce the upfront cost further.
All Qualifying Heat Pumps for Off-Peak Tariff
18 heat pump hot water systems meet our criteria for off-peak tariff. Sorted by tank capacity (largest first).
| System | Tank | COP | Refrigerant | Noise | Min Temp | Timer | Price | Warranty |
|---|---|---|---|---|---|---|---|---|
| Ecogenica R 290 TOP | 290L | 5.0 | R290 | 50dB | -15°C | Smart Timer | $2,600 | 7yr / 5yr |
| iStore 270L VALUE | 270L | 4.8 | R290 | 46dB | -7°C | Smart Timer | $2,790 | 5yr / 5yr |
| Emerald All-In-One 320L | 320L | 4.9 | R290 | 49dB | -7°C | Smart Timer | $3,590 | 5yr / 5yr |
| Solahart Atmos Eco 280L | 280L | 5.2 | R290 | 45dB | -7°C | Smart Timer | $3,500 | 7yr / 3yr |
| Emerald All-In-One 270L | 270L | 4.9 | R290 | 49dB | -7°C | Smart Timer | $3,290 | 5yr / 5yr |
| Rinnai Enviroflo 315L | 315L | 5.0 | R290 | 48dB | -5°C | Smart Timer | $4,200 | 7yr / 3yr |
| Evoheat 270-E | 270L | 4.7 | R290 | 46dB | -7°C | Smart Timer | $3,600 | 6yr / 5yr |
| Apricus APHP-R290-260 | 260L | 4.1 | R290 | 43dB | -7°C | Smart Timer | $3,500 | 5yr / 5yr |
| Rinnai Enviroflo 250L | 250L | 5.0 | R290 | 48dB | -5°C | Smart Timer | $3,850 | 7yr / 3yr |
| Thermastore Heatwave 270 | 270L | 4.3 | R290 | 46dB | -7°C | Mid-range Timer | $3,000 | 6yr / 5yr |
| Rheem Ambiheat HDc270 | 270L | 4.5 | R513a | 48dB | -5°C | Mid-range Timer | $3,629 | 7yr / 3yr |
| Reclaim Energy CO2 315L | 315L | 5.0 | R744-CO2 | 37dB | -25°C | Smart Timer | $5,500 | 10yr / 6yr |
| Reclaim Energy CO2 250L | 250L | 5.0 | R744-CO2 | 37dB | -25°C | Smart Timer | $5,000 | 10yr / 6yr |
| Thermann 315L CO2 Split | 315L | 5.0 | R744-CO2 | 37dB | -25°C | Smart Timer | $5,800 | 10yr / 6yr |
| Thermann 250L CO2 Split | 250L | 5.0 | R744-CO2 | 37dB | -25°C | Smart Timer | $5,223 | 10yr / 6yr |
| Sanden Eco Plus 315L | 315L | 5.0 | R744-CO2 | 38dB | -25°C | Smart Timer | $6,200 | 10yr / 6yr |
| Reclaim Energy CO2 400L | 400L | 5.0 | R744-CO2 | 37dB | -25°C | Smart Timer | $6,500 | 10yr / 6yr |
| Sanden Eco Plus 250L | 250L | 5.0 | R744-CO2 | 38dB | -25°C | Smart Timer | $5,800 | 10yr / 6yr |
Tank Sizing for Off-Peak Tariff
With off-peak tariffs, the tank must store a full day's hot water from a single overnight heat cycle. For 2-3 people (150–200L daily), a 250L tank is the minimum. For 4-5 people (250–350L daily), 315L+ is required. Oversizing by 20-30% is advisable because the heat pump may take longer to reach full temperature in winter.
| Household Size | Daily Use (approx.) | Minimum Tank | Recommended Tank |
|---|---|---|---|
| 1 person | 50-80L | 160L | 200L |
| 2 people | 100-150L | 200L | 250L |
| 3 people | 150-220L | 250L | 270L |
| 4 people | 200-300L | 270L | 315L |
| 5-6 people | 300-400L | 315L | 340-400L |
Annual Running Cost Estimates
Based on a 3-person household using approximately 200L of hot water per day (10.5kWh thermal energy). Heat pump costs calculated using the COP of our top pick (Ecogenica R 290, COP 5.0).
| Energy Source | Rate | Annual Cost | Saving vs Gas |
|---|---|---|---|
| Gas hot water (storage) | ~$0.05/MJ | $767 | - |
| Electric resistive | $0.32/kWh | $1,226 | +$459 |
| Heat pump (peak rate) | $0.32/kWh | $245 | $522 saved |
| Heat pump (off-peak) | $0.14/kWh | $107 | $660 saved |
| Heat pump (solar surplus) | $0.00/kWh | - | $767 saved |
Estimates assume 90% gas heater efficiency, COP 5.0 for heat pump calculations. Actual costs vary by location, usage patterns, tariff structure, and seasonal conditions. Solar surplus assumes 100% of heating occurs during solar production hours (practical savings are typically 70-90% of this).
Government Rebates for Heat Pump Hot Water
All 18 of the qualifying heat pumps above are eligible for government rebates, which can reduce the upfront cost by $700–$2,500 depending on your state. Federal Small-scale Technology Certificates (STCs) apply in all states.
Frequently Asked Questions: Heat Pumps for Off-Peak Tariff
How much cheaper is off-peak electricity for running a heat pump?
Can I use off-peak tariff and solar together?
What timer type do I need for off-peak operation?
Do I need a controlled load circuit installed?
Ready to Switch to Heat Pump Hot Water?
Get obligation-free quotes from licensed installers in your area. Compare prices, check your rebate eligibility, and find the right system for your off-peak tariff needs.
Get Heat Pump QuotesRelated Guides
Heat Pump Hub
Compare all 28 heat pump hot water systems available in Australia.
Ecogenica R 290 Review
Full specs, pros and cons, and pricing for our top off-peak tariff pick.
iStore 270L Review
Full specs and pricing for our best value off-peak tariff pick.
Compare Heat Pumps
Side-by-side comparison tool for any two heat pump hot water systems.
Best for Cold Climate
Alpine regions, Tasmania, Canberra, and southern highlands
Best for Replacing Gas Hot Water
Switching from a gas storage or continuous flow system
Best for Large Household
4-6+ people or high hot water demand
Best for Solar Homes
Running your heat pump on rooftop solar surplus
Best for Small Home or Apartment
1-2 people, limited outdoor space