Submitted by Nedjma.Loucif on Fri, 24/03/2017 - 15:03
Hot Water System

Is your old hot water system due for replacement?

The day has finally come for you to replace your old hot water system. All those years of wear and tear, extreme temperatures, corrosion and exposure to the elements have taken their toll. Yet, where should you start looking for a suitable replacement? What’s the most affordable and efficient approach, taking into account your existing set-up?

These are questions we hear on a daily basis at Solargain. To help you choose the best replacement for your household, we’ve put together some recommendations based on the type of hot water system you already have installed.


I have a roof-mounted solar hot water system with electric boost, a tank and solar panels on the roof.

Given that you already have a solar hot water system mounted on your roof, you are best replacing this with another roof-mounted or close-coupled style of hot water system. This will reduce labour costs on the installation as all the plumbing and electricals are already in situ. We recommend you choose a Solargain 300L Twin Panel Roof Mount System with Electric Boost. It uses natural circulation technology and requires no moving parts or pumps, making it one of our most reliable and long-lasting systems.


I have an electric hot water system with a round storage tank positioned on the outside of my home.

Electric hot water systems tend to be incredibly inefficient. They use a significant amount of electricity to maintain the temperature of the water in the storage tank at the right level. When paired with an off-peak tariff, this kind of system can seem more economical to run. However, it still consumes a lot of power. As electricity prices continue to rise in Australia and as ‘time-of-use’ metering becomes more prevalent, electric hot water systems on off-peak tariffs will become much more expensive to operate, especially in the long term.

So what should I replace my electric hot water system with, we hear you ask. Well, you have three options. All three recommendations involve switching to solar. However, the type of installation you choose comes down to personal preference:

Firstly, there is a ground-mounted solar hot water system with electric boost and flat, low-profile solar panels on the roof. A ground-mounted storage tank will save you money by using the existing plumbing and electrical fittings that are currently connected to your old electric hot water system. Installation and servicing costs also tend to be lower than regular roof-mounted solar hot water systems, as everything is easier to access, being at ground level. We recommend installing flat solar panels (which are about 75% efficient) in areas with warmer climates as they offer a large surface area and are designed with an open loop water flow.

Your second option is to install a roof-mounted solar hot water system with electric boost. This has the potential to free up a lot of wasted space that your old electric hot water system was taking up. In this case, the plumbing and electrical connections are redirected to the new hot water system, up on the roof. A huge benefit of this kind of system is its reliability. Roof-mounted systems require no pumps and have no moving parts. Instead they rely on the laws of physics, whereby cold water naturally flows down through the solar panels; as it heats up, it rises up into the storage tank ready for use. This type of system works best in warmer climates as the water can flow freely through the panels.

Your final option when replacing an electric hot water system is to choose an evacuated-tube solar hot water system with electric boost. These systems are fantastic for people living in cooler climates or with a higher-than-average demand for hot water. They operate at around 94% efficiency and continue to produce piping hot water, even on overcast and cloudy days. Evacuated-tube hot water systems can be ground mounted or use a split system design. They also offer flexible options for mounting the collection tube panels. Operating without the need for glycol, they rely on direct heat transfer for maximum efficiency. We recommend this kind of system for people living in southern Australia, in level 2 rated (minus 15 degrees) frost prone areas.


I have a gas hot water system with a rectangular storage tank positioned on the outside of my home.

On the face of it, gas hot water systems use approximately the same amount of energy as electric hot water systems. Therefore, with the price of gas currently cheaper than electricity, a gas hot water system may seem like a more affordable option. Yet, as worldwide gas shortages continue, some media outlets are predicting a potential 200-400% increase in the price of gas in Australia over the coming years, blamed on rising international demand for gas. If this is the case, Australian consumers with an average annual gas bill of around $500, may be forking out closer to $2000 for gas each year!

Bearing this in mind, we suggest you consider the long-term benefits that come with switching to solar, or at least weigh up some of the benefits that come from incorporating solar power in your home. If you really enjoy cooking with gas, you might like to weigh up keeping your gas connection, but supplementing it with solar panels to supply the bulk of your electricity needs, batteries to store energy efficiently, as well as solar hot water.

When it comes to hot water, gas-boosted solar hot water is a definite winner. These systems operate in much the same fashion as an electric booster. Once the water has been heated naturally via your solar panels, an in-line gas booster only switches on as needed, to top up the temperature of the water in the storage tank if it falls lower than 70 degrees Celsius.

If you’re thinking about combining the power of solar hot water with the efficiency of gas, we recommend the following in-line gas-boosted hot water systems, depending on where you’d like to install your panels:

Roof-mounted solar hot water with in-line gas booster

Ground-mounted solar hot water with in-line gas booster

Evacuated-tube solar hot water with in-line gas booster


Still need help deciding on the best solar hot water system for your home?

At Solargain, we appreciate the process of choosing a replacement hot water system can be confusing and a bit daunting. That’s where our years of experience installing, servicing and repairing hot water systems come in handy. If you’d like to speak with one of our friendly staff about the best approach for your household, feel free to give us a call on 1300 73 93 55 or you can contact us online.