If you’re weighing up a heat pump hot water system, running costs are probably your first question. Fair enough. No one wants to swap one expensive system for another.
Here’s the honest answer:
A heat pump hot water system in Perth typically costs between $116 and $455 per year to run, depending on your Synergy tariff and household usage. Compare that to a standard electric storage system, which can cost well over $1,600 per year for the same household, and the difference is significant.
Key Takeaways
- A heat pump hot water system costs roughly $116-$455/year to run in Perth, versus $1,200-$1,700 for standard electric storage (Ecoheat Energy case study, 2025).
- Heat pumps use 3-4 times less electricity than conventional electric systems, with a COP of 3.0-5.0.
- STC rebates of $800-$1,200 are available to WA homeowners, reducing upfront costs significantly.
- Most Perth households recover their investment within 3-4 years.
What Does a Heat Pump Hot Water System Actually Cost to Run Each Day?
A heat pump hot water system uses around 3-4 kWh of electricity per day for a typical Perth household (Ecoheat Energy, 2025). At Synergy’s standard Home Plan A1 rate of approximately $0.31/kWh, that works out to roughly $0.93-$1.24 per day, or $340-$455 per year.
If you shift your system to run during off-peak hours using Synergy’s Midday Saver tariff, that daily cost drops to as low as $0.32 – putting annual running costs closer to $116.
That’s a meaningful difference depending on which tariff you’re on.
What drives that daily usage?
Heat pumps work by pulling heat from the surrounding air and transferring it into your water tank – rather than generating heat directly from electricity.
This process, measured by the Coefficient of Performance (COP), means the Reclaim heat pump we install produces up to 5 kW of heat for every 1 kW of electricity it consumes. At a COP of 3.0-5.0, it’s far more efficient than any resistive electric element.
In practical terms, your system does more with less.
Perth’s mild climate helps too. Heat pumps perform at their best when ambient air temperatures sit above around 10 degrees C. Perth’s winter lows average around 13 degrees C, which means our systems run efficiently year-round without the performance drop you’d see in colder southern states.
For a full breakdown of system types and sizing, see our heat pump sizing and performance guide for Perth homes.
How Does That Compare to Gas and Electric Hot Water?
Standard electric storage hot water systems are the most expensive to run of the common options. A family of four using 15 kWh of hot water per day on Synergy’s Home Plan A1 can expect to pay around $1,697 per year in electricity for hot water alone (Ecoheat Energy case study, Joondalup household, 2025).
Switch to a heat pump on the same tariff, and that drops to around $453. Move to the Midday Saver tariff, and it falls to around $117.
| System Type | Estimated Annual Cost (Perth) |
| Standard electric storage | $1,200 – $1,700 |
| Natural gas storage | $500 – $900 |
| Heat pump (standard tariff) | $340 – $455 |
| Heat pump (Midday Saver tariff) | $116 – $200 |
Estimates based on a household of 3-4 people, Synergy Home Plan A1 rates, and typical daily hot water usage.
Those are estimates for a typical household. To see the figures for your own usage and tariff, run them through our hot water savings calculator.
Gas is cheaper than standard electric, but it’s still considerably more expensive than a heat pump, and gas prices in WA have been rising steadily. Unlike gas, a heat pump runs entirely on electricity, which means it can also draw on solar panels if you have them installed. That pairing can push running costs even lower.
Perth’s Midday Saver tariff is particularly well-suited to heat pump systems. The bulk of solar generation – and the lowest grid prices – aligns with midday, exactly when a heat pump can be scheduled to run. Most other hot water systems can’t take advantage of this in the same way.
According to Ecoheat Energy’s case study data from a Joondalup family in 2025, switching from a standard electric system to a Reclaim heat pump on the Midday Saver tariff saved over $1,200 per year. That figure comes from a real WA household’s bill comparison before and after installation.
Wondering how heat pumps stack up against solar hot water? Read our heat pumps vs solar hot water comparison for Perth homes.
What About the Upfront Cost and Payback Period?
A heat pump hot water system in Perth typically costs $3,000-$6,000 fully installed, depending on the model and tank size (Ecoheat Energy, 2025). That sounds like a lot compared to a basic electric replacement. But there are two things worth knowing before you dismiss it on price alone.
The STC rebate
Under the federal government’s Small-scale Renewable Energy Scheme, heat pump hot water systems qualify for Small-scale Technology Certificates (STCs). In WA, that rebate is typically worth $800-$1,200 off the upfront cost, handled by your installer. We take care of the paperwork – you just pay the reduced price.
The payback period
When you factor in the rebate and the annual savings on your Synergy bill, most Perth households recover the additional cost of a heat pump within 3-4 years. After that, you’re running one of the most energy-efficient hot water systems available – for the next 15-20 years.
We’ve installed Reclaim heat pumps across Perth’s northern suburbs and southern corridor. Households that pair their system with the Midday Saver tariff consistently hit payback closer to the 3-year mark. It’s the single biggest thing you can do to improve your return.
A simple way to think about it: the higher upfront cost buys you years of lower bills. A standard electric system might cost less to buy, but it costs more every single quarter for as long as you own it.
Want to know exactly what to expect from the install process? Get in touch with our team, and we’ll walk you through your options, no pressure.
Does the Heat Pump Size Affect Running Costs?
Yes, but it’s more nuanced than bigger equals more expensive. The right-sized system for your household will actually cost less to run than an undersized one that constantly works harder to keep up with demand (Ecoheat Energy product guidance, 2025). An oversized system costs more upfront without delivering proportional savings.
Reclaim heat pumps are available in 160L, 250L, 315L, and 400L tank sizes. Here’s a rough guide for Perth households:
Household Size | Recommended Tank | Approx. Daily kWh |
1-2 people | 160L | 1.5-2 kWh |
3-4 people | 250L | 3-4 kWh |
4-5 people | 315L | 4-5 kWh |
5+ people | 400L | 5-6 kWh |
Figures are approximate and depend on usage patterns, inlet water temperature, and tariff settings.
Sizing matters. Get it right the first time, and your running costs stay predictable. That’s why we always recommend a consultation before installation, not to upsell you on the largest tank, but to make sure you’re not paying to heat water you don’t use.
See the full range of available sizes on our Reclaim Heat Pump product page.
Can I Run a Heat Pump Hot Water System on Solar Panels?
Yes, and it’s one of the best combinations available for Perth homeowners. If you have a rooftop solar system, you can schedule your heat pump to run during peak generation hours – typically between 10 am and 2 pm, so it’s drawing on your own solar power rather than the grid (Ecoheat Energy, 2025).
Perth receives more sunshine hours per year than almost any other Australian capital, which makes the heat pump and solar pairing particularly effective here.
A system scheduled to run on solar can cut hot water running costs to near zero on sunny days.
When paired with solar, many Perth households report that their net hot water running costs fall to a fraction of what they’d pay otherwise, sometimes close to zero on clear days.
Even without solar, the Midday Saver tariff achieves a similar result by shifting usage to when grid electricity is cheapest.
We can help you configure your heat pump’s timer settings to align with your solar generation window or your preferred tariff period. It’s a straightforward setup, and we walk you through it at installation.
Learn more about how heat pumps and rooftop solar panels work together.
Frequently Asked Questions
How much electricity does a heat pump hot water system use per day in Perth?
A typical heat pump hot water system uses around 3-4 kWh of electricity per day for a household of 3-4 people. That’s compared to 10-15 kWh for a standard electric storage system doing the same job. Perth’s warm climate means performance stays consistent year-round, keeping usage at the lower end.
What is the cheapest tariff to run a heat pump on with Synergy?
Synergy’s Midday Saver tariff offers some of the lowest per-unit rates during midday hours, when solar generation is highest across the grid. Scheduling your heat pump to run between roughly 9am and 3pm on this tariff can reduce annual running costs to as low as $116-$200 for a typical Perth household.
How long before a heat pump pays for itself in Perth?
Most Perth households see a payback period of 3-4 years when factoring in the STC rebate ($800-$1,200) and annual electricity savings compared to a standard electric storage system. Households on the Midday Saver tariff or with solar panels typically reach payback closer to the 3-year mark.
Is a heat pump hot water system worth it for a small household in Perth?
Yes, even for smaller households. A 160L Reclaim heat pump uses around 1.5-2 kWh per day and qualifies for the same STC rebate as larger systems. The annual running cost for a 1-2-person household can be as low as $80-$150, making it one of the most cost-effective hot water options regardless of household size.
Do heat pump hot water systems work well in Perth's winter?
Yes. Heat pumps perform best in ambient air temperatures above 10 degrees C. Perth’s average winter minimum is around 13 degrees C, which means our systems run efficiently even on the coldest days. Unlike heat pumps installed in Victoria or Tasmania, Perth systems don’t experience the same efficiency dip in winter months.
For more details on system performance across seasons, see our detailed guide to heat pump hot water costs and savings in Perth.
