It’s 6 am Tuesday, and you step into the shower, only to get hit with freezing water. Your hot water system is making weird sounds, and there’s a puddle underneath.
Now you’re Googling “hot water system replacement” and getting contradictory advice. Electric? Gas? Heat pumps? This decision affects your wallet for the next 10-15 years.
The truth is, there’s no single “best” hot water system. The right choice depends on whether you have natural gas connected, your household size, and your budget. This guide gives straight answers based on Australian costs and real government rebates available in 2026.
The best hot water system depends on whether you have a gas connection, how many people are in your home, and your budget. Gas works well for homes already on natural gas with high demand, heat pumps deliver the lowest running costs for homes without gas (despite higher upfront prices), and electric systems are the budget option, especially with off-peak rates or solar.
| Factor | Electric Storage | Gas Continuous Flow | Heat Pump |
| Installation Cost | $1,200-$2,500 | $2,200-$4,500 | $3,500-$5,500 |
| Running Cost/Year | $700–$1,000 | $350-$450 | $250-$350 |
| Government Rebates | Minimal | None | $500-$1,500 |
| Energy Rating | 3-4 stars | 5-6 stars | 6-7 stars |
| Lifespan | 10-15 years | 10-20 years | 15-20 years |
Electric hot water systems heat water with elements inside storage tanks, like a giant kettle. They heat water during off-peak hours (10 pm-7 am) on controlled-load tariffs, or at any time on standard rates. On average, electric water heaters take 2-4 hours to fully heat water.
Most Australian households use electric storage water heaters holding 125-400 litres. For example:
Your electricity tariff makes a huge difference to running costs. Controlled-load tariffs (off-peak electricity) cost 15–25 cents per kWh (depending on state), compared with 28–40 cents for peak rates.
That’s 40-60% cheaper, which can bring electric running costs closer to those of gas hot water systems.
Gas hot water systems burn natural gas or liquefied petroleum gas (LPG) to heat water. They come as storage tanks or instantaneous gas systems (continuous flow) that heat water on demand.
Natural gas is supplied through pipes from the street, whereas LPG is stored in gas bottles, which are common in regions without a gas supply.
Modern gas systems use electronic ignition instead of pilot lights, reducing your energy consumption. Instantaneous gas systems provide 16-32 litres per minute. A 16L/min unit suits 2-3 people, while families of 4-5 need a 20-24L/min continuous-flow system.
Heat pump hot water systems extract warmth from air and transfer it to water, like a reverse refrigerator. They’re 3-4 times more energy efficient than standard electric hot water systems.
For every 1 kWh of electricity consumed, heat pumps transfer 3-4 kWh of thermal energy into water. This exceptional energy efficiency means using 60-75% less electricity than conventional electric water heaters.
Heat pump systems are available as integrated units (the compressor and tank combined) or as split systems (separate components). Tank sizes range from 170 to 315 litres, but be mindful that the outdoor compressor needs 1 metre of clearance for airflow.
These systems operate down to -10°C, covering all Australian climates. Heating time takes 2-4 hours for a full tank.
| System Type | Size | Installed Cost |
| Electric Storage | 125-160L (1-2 people) | $1,200-$1,600 |
| 250-315L (3-4 people) | $1,600-$2,200 | |
| 315-400L (5+ people) | $2,000-$2,500 | |
| Gas Continuous Flow | 16L/min (2-3 people) | $2,200-$2,800 |
| 20-24L/min (4-5 people) | $2,800-$3,800 | |
| 26-32L/min (6+ people) | $3,500-$4,500 | |
| Heat Pump | 170-210L (2-3 people) | $3,500-$4,200 |
| 250-315L (4-5 people) | $4,200-$5,500 |
Keep in mind that you will need to pay extra for a gas connection ($2,000-$4,000+ if needed) and for removing your old system ($150-$300).
These figures assume electricity at 28–40c/kWh peak and 15–25c/kWh off-peak, depending on state; natural gas at 3–10c/MJ, depending on state; and 50 L of hot water per person per day.
Gas connection costs make heat pump systems the clear winner for homes without natural gas.
Heat pump systems and solar hot water systems qualify for rebates.
Small-scale Technology Certificates (STCs) reduce costs by $500-$1,000. Your installer handles this as an upfront discount.
Victorian Energy Efficiency Certificates (VEECs) provide $450–$675. Locally made heat pumps are eligible for up to $1,400 through Solar Victoria. Total rebates range from $2,000 to $2,700 for eligible households.
The Energy Savings Scheme provides Energy Savings Certificates (ESCs) worth $300-$1,000. Combined with STCs, NSW residents receive $800- $2,000.
Mainly federal STCs ($500-$800).
REPS certificates reduce costs by $400-$800. Total with STCs: $900-$1,800.
Visit energy.gov.au to confirm current rebates. Same Day Hot Water Service can help you identify what’s available in your area.
Heat pump water heaters top the charts with 6 to 7-star energy ratings. Electric storage water heaters are rated 3 to 4 stars, while gas continuous-flow systems are rated 5 to 6 stars.
Where you live makes a difference to your carbon footprint. Victoria and NSW still rely more heavily on fossil fuels for electricity generation, so if emissions matter to you, a heat pump or gas system will serve you better than a standard electric setup in those states.
Tasmania and South Australia are a different story, as both run largely on renewables, which makes a standard electric system more competitive on the emissions front.
Regardless of where you are, heat pumps use 60–75% less electricity than conventional electric systems, making them the lowest-emissions choice across the board.
| Choose This System | When This Applies to You |
| Electric Hot Water |
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| Gas Hot Water |
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| Heat Pump |
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Choosing the right hot water system comes down to three things. Whether you have gas connected, how many people live in your home, and what you can afford up front versus over the long term.
If you already have natural gas and a busy household, gas systems make sense. If you don’t have gas, heat pumps cost more upfront, but the savings on operating costs add up quickly. And if you’re on a tight budget and have low usage, off-peak electricity gets the job done.
Don’t just look at the sticker price. A heat pump might cost $1,500 more up front, but if it saves you $400 a year, you break even in under 4 years. Then it keeps saving you money for another decade.
We’re seeing more Australians choose heat pumps in 2026. Government rebates have made them genuinely affordable, and the efficiency speaks for itself.
Need your system replaced? Same Day Hot Water Service installs all three types across Sydney, Melbourne, Brisbane, Perth, Newcastle, Central Coast, Wollongong, and Sunshine Coast. We offer free assessments and same-day installation when your system fails.
We don’t push one system over another. We just help you pick what actually works for your home.
Gas is typically 30-40% cheaper to run than standard electric hot water systems. For families, expect $380- $480/year for gas versus $700–$1,000/year for peak electric. Heat pumps are cheapest at $230-$310/year.
Heat pump systems are most efficient, using 60-75% less energy than standard electric systems. They achieve 6-7-star energy ratings, compared to 3-4 stars for electric and 5-6 stars for gas.
Gas continuous flow systems win with instant, unlimited hot water. Heat pumps are slower (2-4 hours to heat a full tank) but work fine when sized correctly for your household.
Yes. Modern heat pump hot water systems operate efficiently down to -10°C and are suitable for all Australian climates, including Melbourne and Canberra winters.