Hot Water Systems Compared

Compare hot water systems from Solahart, Vulcan, Rheem, Rinnai, Bosch, Dux and AquaMax. Brands were reviewed on their effectiveness, reliability, quietness, ease of use, after sales service/warranty, value for money and overall satisfaction.

See our Ratings Methodology.

Most Satisfied Customers | Solahart & Vulcan

Solahart and Vulcan have emerged as the best-rated brands for hot water systems in Australia, both recording five stars for overall customer satisfaction in our latest comparison. The two brands also picked up top marks in areas relating to effectiveness, reliability and ease of use.

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Competition heats up as Solahart and Vulcan rated best for hot water systems

You might think (understandably) that all hot water systems are basically the same – after all, they all do more or less the same thing, right? Well, they certainly all heat up your hot water so you can enjoy nice showers at the end of a long day – but how they go about doing it, plus how reliably they do it, and how much they cost to do it, can vary greatly. Finding the best water system for your home is no easy task. You first need to understand what different types of systems are available, get to grips with their ongoing running costs, and find a product that meets your needs and budget.

To help you on the road to a reliable and cost-effective water-heating solution, Canstar Blue has produced this guide. In it, we review the types of water systems available in Australia, compare ongoing running costs, and find out which brands are rated best on factors like effectiveness, reliability, ease of use, and value for money.

To produce our customer satisfaction ratings, we’ve surveyed hundreds of households across Australia – finding out which type of system they use, how much they paid for it, and how they rate their brand of choice across seven key variables. The idea is to give you all the information you need to make an informed decision before you go out and buy your next hot water system. Finding out what other Aussies think of the rated brands is a great place to start.

Best-Rated Hot Water Systems

Best hot water system

The seven brands in our latest hot water systems review have been rated in the following order for overall customer satisfaction:

  • 1st Solahart / Vulcan
  • 3rd Rinnai
  • 4th AquaMax
  • 5th Rheem
  • 6th Dux
  • 7th Bosch

This year, we’ve seen a tie between Solahart and Vulcan, both scoring five stars for overall customer satisfaction. In addition to the most important variable, Vulcan also achieved five stars for effectiveness and reliability, while Solahart got top marks for quietness and ease of use. Both brands also received five stars for after sales service/warranty.

Elsewhere, Rinnai, AquaMax and Rheem achieved four stars overall, with Dux and Bosch behind on three stars. An honourable mention is also deserving of Rinnai as the only brand to earn five stars on value for money, while also recording top marks for after sales service/warranty. There was also a strong showing from AquaMax with five stars on effectiveness, reliability and ease of use.

Now we know which brands are rated best, let’s dive into detail about the types of hot water systems available in Australia, what they are likely to cost you upfront, and how much they’re likely to add to your ongoing energy bills.

Types of hot water systems

The humble hot water system might seem like an unlikely culprit for large energy bills – but did you know that the cost of heating water can make up 30% of an average Australian household’s total electricity bill? Your system may be costing you big time – depending on the type you have – so we’ve compared electric, gas, solar and heat pump hot water systems to help you find the best and most cost-effective water heating solution for your home.

Basically, hot water systems come in two fundamental designs – ‘storage’ and ‘continuous flow’ (also known as instantaneous).

  • Storage hot water systems heat and maintain warm water in a tank until it is ready to use. This provides instant hot water, but is limited by storage capacity.
  • Continuous hot water systems rapidly heat up an unlimited amount of water when you need it. While it does take a few moments to heat up, an instantaneous system won’t waste energy by keeping water warm when no one is using it.

You’ll find these two types of systems available in electric, gas, solar and heat pump varieties – each with pros and cons to their energy source. The example pictures are courtesy of Rheem.

Electric Water Heaters

How they work

Electric Water Heaters Explained

Electric storage hot water systems heat water using an electric-powered element which sits at the base of the water tank. Continuous systems work in a similar way, but instead the element is coiled around the pipes to rapidly heat the water inside.


Electric hot water systems have relatively low upfront costs, and are a reliable way to keep your water warm. The majority of large electric storage hot water systems are connected to controlled load tariffs and do the majority of their heating at off-peak periods to help reduce your energy bills.


Electrical hot water systems are almost always the most expensive long-term hot water solution if used on a continuous day rate tariff. The electricity that powers them may also have high greenhouse gas emissions if the power does not come from renewable sources such as solar PV, wind, or from a hydro scheme.

  • Cost: $200 to $2,000

Gas Water Heaters

How they work

Gas Water Heaters Explained

Storage gas water systems use a gas burner to continuously heat and maintain water in a tank at 60°C. Continuous flow systems also use a burner which ignites only when the water is needed.


Gas hot water systems will produce few greenhouse gas emissions. Additionally, depending on your location, gas systems are usually considered to have lower usage rates compared to electricity, making them a more cost-effective option long term.


Gas hot water systems are only really viable if you’re connected to mains gas, as using LPG bottles is more expensive, and creates the risk of running out of hot water. Gas hot water systems must be located outside, or have an exhaust vent if they are located inside.

  • Cost: $800 to $2,000

Solar Water Heaters

How they work

Solar Water Heaters Explained

Solar hot water systems are storage units which generate heat from the sun using panels installed on the roof of the property. This heat is used to warm and maintain the water in your tank. When there is insufficient solar generation, systems can be boosted to a temperature of 60°C by either electric or natural gas boosters. Solar water systems can be split-system (like the one pictured) or combined.


Solar hot water systems could reduce your hot water system’s energy consumption significantly, though the potential savings are disputed and naturally subject to your personal circumstances, including where you live. Solar hot water systems are generally considered the most environmentally-friendly option. Accredited solar systems might also be eligible for STC rebates from the federal government through the Clean Energy Regulator, as well as other state-specific rebate schemes.


Solar hot water systems have the greatest upfront costs – anywhere from $2,000 to $7,000 after rebates, depending on the system size and excluding any installation costs. Some solar hot water systems may also be unreliable on overcast days, although most models will kick-over to natural gas or electric back-up heating if the water isn’t hot enough.

  • Cost: $2,000 to $7,000

Heat Pump Water Heaters

How they work

Heat Pump Water Heaters Explained

Heat pumps include a fan that draws warm air into the system, which is transferred to the water storage tank. It’s essentially a reverse fridge. Rather than pumping out hot air to keep your fridge cool, it pumps hot air in to heat the water up.


Heat pumps are one of the most energy-efficient hot water solutions. While they need electricity to run, they are roughly three times more efficient than traditional electric water heaters.


Heat pumps are only really suitable in warm environments. While some heat pumps come with boosters, if the climate isn’t suitable, there is little benefit in spending the extra money on a heat pump. They are also considered unreliable and servicing costs are generally expensive.

  • Cost: $2,500 to $4,000

Which type of hot water system is most popular?

Our 2019 survey found that households that have purchased a new hot water system in the last five years spent an average of $1,619. Respondents reported buying the following types of hot water systems:

  • Gas: 42%
  • Electric: 39%
  • Solar: 12%
  • Heat pump: 5%

A further 1% were unsure which type of system they have, while the remaining 1% said they have another type.

Notably, the majority of survey respondents only purchased their new hot water system because their old one failed (65%). However, 16% said it was because they wanted to upgrade their hot water system, while a further 10% did so because they wanted to increase their water capacity.

Hot water system running costs

The following table – courtesy of the Victorian government – provides an example of the estimated running costs of different types of hot water systems. As mentioned, natural gas boosted solar storage hot water systems are the cheapest over time, with an annual cost of only $65 for a medium-sized household (three people). LPG gas and continuous flow electric systems prove to be the most expensive, costing more than $600 and $900 a year respectively. However, running your system on a controlled load tariff can reduce running costs significantly, as the table shows. The following calculations, based on a three-person household in Victoria (120L/day), should be treated as a general guide only:

Water Heater Type Energy Star Rating Annual Energy Cost Annual GHG emissions (kg/yr)
Natural gas – storage 5.5 $350 775
4 $415 915
Natural gas – instant 7 $295 690
5.5 $340 785
LPG – storage 5.5 $560 910
4 $665 1075
LPG – instant 7 $465 795
5.5 $535 905
Peak tariff – storage n/a $925 3420
Peak tariff – instant n/a $780 2875
Off-peak tariff – storage n/a $700 3935
Natural gas boosted High efficiency $65 165
Standard $85 215
LPG boosted High efficiency $95 185
Standard $130 240
Electric boosted – peak tariff High efficiency $260 950
Standard $365 1345
Electric boosted – off-peak tariff High efficiency $185 1040
Standard $265 1475
Heat Pump
Peak tariff High efficiency $245 895
Standard $385 1415
Off-peak tariff High efficiency $160 885
Standard $250 1395

Annual costs based on Melbourne household with average daily hot water use. For gas instantaneous and gas boosted solar water heaters, running costs take electricity use into account. Electricity tariffs based on general usage rate of 31.9 c/kWh, and off-peak rate of 20.9 c/kWh. Natural gas tariffs based on typical declining block structure for house with gas heating, water heating and cooking. Natural gas tariffs used for gas storage and instantaneous water heaters: 2.49 c/MJ; 2.46 c/MJ. For solar-natural gas boost, tariff of 2.36 c/MJ has been used. LPG tariff based on bulk supply (210kg cylinder) in Melbourne area: $1 per litre or 4.0 c/MJ. Energy tariffs do not include the annual supply charge or cylinder rental fee.

Solar and heat pump water heaters efficiency levels are based on the following STC allocations in Zone 4 (southern Victoria): solar gas boosted – standard (29), high efficiency (33); electric boosted solar – standard (27), high efficiency (31); heat pump – standard (28), high efficiency (35).

What’s the best type of hot water system?

If you’re connected to mains gas and your home receives at least moderate amounts of sunlight, then the most ideal system for you could be a solar storage hot water system with gas boosters. If your home doesn’t get much sunlight, the next best thing in terms of running costs would likely be a continuous flow gas system.

However, there is no ‘one size fits all’ solution when it comes to cutting your energy bills. It could be said that you should avoid electric hot water systems if at all possible, particularly continuous flow models as they have high emissions and are often considered to be the most expensive option. But the cheapest hot water system for you will come down to personal circumstances.

Keep in mind, however, that buying a hot water system is often a trade-off between initial upfront costs and long-term energy savings. If you want the most efficient system from the point of view of lowering utility bills, you’ll probably have to fork out more in the first instance. Whether or not that investment pays off in the long-run will depend entirely on your personal circumstances, such as how much water you use and how much you pay for power.

Let’s now get an overview of the seven brands in our review, with details about the types of hot water systems they offer.


Solarhart hot water heater

As you would guess from the name, Solahart is a provider of hot water systems that specialises in solar power as the energy source. The company says it makes sense to get your hot water for free, powered by the sun, resulting in significant savings on energy use, as well as a reduction in greenhouse gas emissions. Given that water is heated by power of the sun, it makes sense that Solahart has a rooftop system that use the Thermosiphon principle to collect heat from the sun and transfer it to your hot water. Solahart also sells split system water heaters where the solar panels are on the roof but water tank remains on the ground, in addition to heat pump systems when solar power might not be suitable or reliable. For pricing, Solahart invites enquiries via its website.


Vulcan hot water heater

Vulcan is a company that promises high-quality and performance from its hot water systems, but at “very affordable” prices. It says its water systems are reliable because they’re built with the best quality materials and proven technology, including tough storage cylinders made from high strength steel and able to withstand varying heating cycle pressures. Vulcan sells both gas and electric hot water systems with a variety of model sizes available. You can obtain a quote via the Vulcan website.


Rinnai hot water heater

Rinnai produces two lines of continuous gas water heater: Infinity and Hotflo. It also produces a range of domestic and commercial solar, electric, gas and heat pump storage systems, along with natural gas boosters and other accessories to manage hot water usage, provide added security, or improve the aesthetics of your system. Prices for a storage system start at around $500, while continuous flow systems will generally set you back at least $1,000. If you’re considering a Rinnai solar hot water system however, expect to pay at least $2,000.


AquaMax hot water heater

AquaMax produces gas storage, electric storage and gas continuous flow hot water systems. The company also has a ‘premium’ range of stainless-steel water storage systems which it claims are lighter, more energy-efficient and easier to maintain than regular models. AquaMax prices start from as low as $400 for its smallest electric storage system. The continuous flow systems are considerably more expensive, however, priced around the $1,200 mark.


Rheem hot water heater

Rheem produces all kinds of water heaters, including electric, gas, heat pump, and solar storage, as well as gas continuous flow systems. Rheem’s hot water systems are deliberately designed to cater for a variety of needs. It has steel systems for added durability, compact systems for those tight on space, plus extra-large models, and plenty more. A small electric Rheem storage system will usually set you back at least $500, with larger models costing up to about $1,500. Continuous flow systems start around $800. Solar hot water with Rheem can cost anywhere between $1,200 and $3,000.


Dux hot water heater

Dux has a huge range of hot water systems, including heat pump, electric, gas, and solar boosted storage systems, as well as gas continuous flow water heaters. Dux’s storage systems come in a plethora of sizes, between 25L and 400L. But if continuous flow is more your style, you might be interested to know that Dux systems have a 6.7-star energy-efficiency rating – higher than most similar models on the market. Small Dux electric storage systems start at around $350, while its continuous flow systems will set you back at least $800. Solar water heating should cost a couple of thousand, depending on the size of the system.


Bosch hot water heater

While Bosch does produce electric and heat pump storage systems, what actually sets the brand apart from others is its range of gas continuous hot water systems, with its patented ‘Optiflow’ technology. Bosch claims its Optiflow hot water systems provide more responsive hot water, and include Bluetooth connectivity so users can track usage data and adjust the water temperature from their phone. Bosch’s Optiflow hot water systems start at a reasonable price of about $800.

How to save on hot water heating

Hot water is a necessity, meaning it’s somewhat of an inevitable cost. That said, there are ways to minimise your hot water system’s impact on your energy bills.

One of the easiest ways households with electric storage systems can save on hot water is with a controlled load tariff. Sometimes just referred to as a ‘dedicated circuit’ or ‘two-rate’ tariff, it’s an arrangement where the hot water system is metered separately to the rest of the house and electricity is charged at a lower rate. Electricity is only supplied to the hot water system during off-peak usage hours – usually from 11pm to 7am depending on the electricity network. During these hours, the hot water system will heat the water and store it for use later on.

Most hot water systems are installed with a dedicated meter, meaning energy retailers will often put you on a controlled load tariff by default. If, for whatever reason, you don’t have a controlled load tariff, you stand to save big by making the switch.

About the author of this page

Megan Birot

This report was written by Canstar Blue’s Home & Lifestyle Content Lead, Megan Birot. She’s an expert on household appliances, health & beauty products, as well as all things grocery and shopping. When she’s not writing up our research-based ratings reports, Megan spends her time helping consumers make better purchase decisions, whether it’s at the supermarket, other retailers, or online, highlighting the best deals and flagging anything you need to be aware of.

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More about hot water heaters

Our latest review of hot water systems saw a number of brands perform well in different areas:

  • Best Overall: Solahart and Vulcan were rated best for overall customer satisfaction.
  • Best for Effectiveness: AquaMax was rated best for effectiveness, followed by Vulcan.
  • Best for Reliability: Vulcan performed best for reliability, closely followed by AquaMax.
  • Best Value for Money: Rinnai was a clear winner on value for money, ahead of Vulcan and AquaMax.
  • Best After Sales Service: Vulcan, Rinnai and Solahart were the standout performers for after sales services.
  • Best for Quietness: Solahart was rated best for quietness, followed by Vulcan and AquaMax.
  • Best for Ease of Use: Solahart was also rated best on ease of use, closely followed by AquaMax and Rinnai.

Frequently asked questions

Canstar Blue surveyed 6,174 Australian adults across a range of categories to measure and track customer satisfaction, via ISO 26362 accredited research panels managed by Qualtrics. The outcomes reported are the results from customers within the survey group who have purchased a new hot water heater in the last 5 years – in this case, 850 people.

Brands must have received at least 30 responses to be included. Results are comparative and it should be noted that brands receiving three stars have still achieved a satisfaction measure of at least six out of 10. Not all brands available in the market have been compared in this survey. The ratings table is first sorted by star ratings and then by mean overall satisfaction. A rated brand may receive a ‘N/A’ (Not Applicable) rating if it does not receive the minimum number of responses for that criteria.



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