Everything you need to know before installing a Hot water system
Choosing the right hot water system for your home is about more than just cost. A good water system can be the difference between reliable hot showers and breakdowns and high water bills. Choosing the right unit will make sure you never face the frustration of running out of hot water. But what type of system is right for you? With so many options on the market, matching the right one to your household can be hard. We’ve put together this guide to hot water systems to help you decide.
What is the difference between solar, gas, electric and heat pump hot water systems?
When it comes to hot water, there isn’t a one-size-fits-all option. Solar, gas, electric and heat pump systems all work a bit differently, and each has its own pros and cons. The best choice often depends on your home, your energy bills and how much hot water you actually use. Here’s a quick look at how each system works and what sets them apart.
Gas Hot Water System
Gas systems come in two main types: continuous flow and storage. Continuous flow only heats water as you use it, so there’s less waste and you never technically run out. Storage tanks, on the other hand, keep hot water ready to go, which means faster delivery but also some heat loss. A good example of a continuous flow unit is the Thermann, which is designed for steady, on-demand hot water. Gas systems are also typically cheaper to run than electric and produce fewer emissions, making them a reliable and efficient choice for many homes.
Electric Hot Water System
Electric systems are usually the cheapest to buy and install, which is why they remain the most common in Australian households. They heat water using elements inside the tank and store it until it is needed. Many models, like this Dux Proflo Model, can be installed discreetly inside or outside the home, making them a flexible choice for different property types. As a category, though, electric systems come with higher running costs compared to gas or solar, and they’re more likely to run out of hot water during periods of high use. They’re affordable upfront but can be less cost-efficient in the long run.
Solar Hot Water System
Solar hot water systems use roof or ground-mounted collectors to capture the sun’s energy and heat water stored in a tank. They are the most energy-efficient choice and can be paired with gas or electric boosters for cloudy days. The Rheem Premier Hiline 52H300 SS system pictured is designed for frost-prone areas and can be fitted with either an electric element or a 6-star continuous-flow gas booster to maintain water temperature when solar gain isn’t sufficient. While the upfront cost is higher than other systems, the long-term savings on energy bills are significant. Solar is the best option if you want to reduce running costs and environmental impact, provided your property suits the installation.
Heat Pump Hot Water System
Heat pumps work differently again, drawing warmth from the air and transferring it to the water in your tank. They’re a highly efficient option, especially in areas with mild to warm climates, and with government rebates they can be very attractive. In NSW, colder winters can reduce their performance, so it’s worth checking how well your location suits the model. Efficiency improvements are being made all the time, however. The Rinnai Enviroflo AR Series is one example of a system that has undergone extensive product testing and is also backed by a 7-year cylinder warranty.
Instant vs Storage Hot Water Systems
Hot water systems generally fall into two categories: instant (also called continuous flow) and storage. An instant system heats the water only when you turn on the tap. This means you never technically run out of hot water, and you are not paying to keep a tank warm all day. Instant systems are compact, efficient and well suited to households that use moderate amounts of water across the day.
Storage systems work differently. They heat water and hold it in a tank, ready to go when you need it. The benefit is faster delivery and the ability to meet high demand at once, which is why storage tanks are common in larger households. The drawback is that they lose some heat over time, so energy use is higher, and once the tank is empty you have to wait for it to refill and reheat.
It is worth noting that your options depend on the type of system. Gas gives you the most flexibility, with both instant and storage models available. Electric systems are usually storage, with instant electric models requiring three-phase power and therefore less common. Solar and heat pumps are always storage, as they rely on heating water in a tank for later use.
How do I know what size tank I need?
The right size tank depends on how many people live in your home and how you use hot water. As a guide, singles and couples often manage with 100 to 160 litres. A household of three to four usually needs 160 to 250 litres, while larger families of five or more are better suited to 250 litres or more, sometimes up to 400 litres.
It is also worth thinking about the future. A growing family, or the addition of a new bathroom, can increase hot water demand. Choosing a slightly larger system now can help you avoid running short later or facing another upgrade sooner than expected.
Which hot water system is the cheapest to run?
Solar offers the lowest running costs over time, especially if your home gets good sun exposure. Gas is generally cheaper than electric, while electric is the most expensive to run.
How long will my hot water system last?
Most electric and gas systems last around 10 years, while solar and heat pump systems can last 15 years or more with proper maintenance. Regular servicing (such as flushing out sediment, checking parts, and relieving the pressure relief valve) helps extend the life of your system. It’s also a good idea to lag (insulate) the hot water pipe, keep the base dry to prevent rust, and clear away any rubbish or leaf matter around the unit.
So what is the best hot water system for me?
The best system depends on your household, your budget and your long-term goals. If you want the cheapest upfront option, electric will do the job, although it will cost more to run over time. Gas is a reliable middle ground that is efficient and less likely to leave you without hot water. Solar is the strongest choice if your property is suitable, as it delivers the greatest long-term savings and the lowest environmental impact.
The right choice comes down to matching the system with your situation. Think about how many people live in the home, how much hot water you use, whether the property is a rental or one you plan to sell, and whether you see value in paying more upfront for lower running costs over time. If you are unsure, our team can assess your property and guide you towards the system that will work best for your needs.
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