Australia is one of the largest markets for solar hot water in the world – and it’s little wonder why. Installing a solar hot water system will help you slash your bills and carbon footprint every year, using the power of the sun to naturally heat your water.

If you’re considering solar hot water for your home, you’re in the right place to get started. Using our years of experience, we’ve collected and answered the most commonly asked solar hot water questions.

If your question isn’t on our list, please don’t hesitate to call us on 1300 73 93 55 – we’re here to help!

The basics of Solar Hot Water

Solar hot water systems use the power of the sun to heat water for use in homes and businesses. Developed over many years, solar hot water systems provide a far more efficient and sustainable method of water heating than traditional electric and gas systems. Particularly popular in Australia, solar hot water is also commonly used in countries that get good amounts of sunlight such as Japan, Greece, China and India.

In most Australian homes, domestic water heating is the largest contributor to greenhouse gas emissions. As utility costs continue to skyrocket, it’s also becoming one of the most expensive.

Solar hot water provides a solution to both these problems. Installing a solar hot water system not only dramatically reduces your carbon pollution but will potentially save you hundreds every year in bills.

On top of all this, installing solar hot water attracts fantastic government rebates and it will increase the value of your home.

Flat Plate
Flat plate solar hot water systems are reliable, efficient and currently the most common systems in Australia. Made from strong tempered and patterned glass, flat plate collectors absorb energy from the sun and use it to heat water. The water is then stored in either a ground or roof mounted tank ready for use.

Evacuated Tube
This relatively recent technology offers significant increases in both performance and efficiency. Unlike flat plate collectors evacuated tube systems consist of several glass tubes installed side-by-side on the roof of your property. Copper pipes inside the tubes heat up as sunlight is absorbed. This heat then transfers to an insulated storage area where water continually flows through and heats. The hot water produced by these systems is usually stored in a ground mounted tank.


As the name suggests, roof-mounted systems exist almost entirely on the roofs of properties, including the solar collectors and storage tank.

In the majority of cases, your solar collectors will be installed in a northerly position, in order to maximise the sun’s energy. Heated water that’s stored in your tank is made accessible to your home via mains pressure delivery.

As you use hot water, cold water travels through your solar collectors, heats up, and re-fills your storage tank - so you’re never left wanting for hot water.

Split System

Like roof-mounted systems, split system solar collectors are installed facing north. Instead of installing the water storage tank on the roof, it’s ground mounted, and usually positioned near a major hot water usage area (laundry, bathroom etc).

As water is heated by solar energy, a sensor activates a circulation pump which pushes the warm water down into the storage tank on the ground. As hot water travels down, cold water travels up to be heated as required.

Evacuated tube hot water systems are almost exclusively installed using the split level method.

Heat Pump

Heat pump technology offers an effective alternative to the traditional hot water heating methods. Easily installed, without the need for solar panels, heat pump technology has been refined over 30 years.

Heat pumps work by absorbing heat from surrounding air. The air is sucked into the unit where it heats a liquid refrigerant and converts into a gas as the temperature rises. The gas is compressed, generating heat, and is passed through copper tubes which are wrapped around the outside of the water tank. The heat is transferred to the water inside, making it heat up.
Though electricity is required during this process, it’s only about a quarter of the amount that is used by a normal electric hot water heater.


Solar PV panels rely on sunlight to generate DC electricity, which is fed into an inverter and converted into home-friendly AC power.

On the other hand, solar hot water collectors use the sun’s heat, or heat from ambient air, to directly warm water.

Solar hot water collectors cannot be connected to the grid (as they do not produce electricity) just as solar PV panels cannot be used to heat water.

Though the technology can look similar, they have entirely different purposes.

Choosing the right solar hot water system depends on a number of variables; including your budget, location, water consumption and personal preferences.

Generally, there’s not much difference between split and roof mounted systems. Both provide similar performance and efficiency. Choosing a roof mounted system may be more of a concern where special reinforcing is needed to support the system’s weight on your roof or in cases where service and maintenance will be especially difficult.

On the other hand, the difference between flat plate and evacuated tube systems is quite substantial. While flat plate systems cost less, evacuated tube systems offer better performance and increased durability.

Still feeling confused? Browse our most popular solar hot water models and then get in touch with our team. Solargain’s solar hot water consultants are specially trained to help you find the perfect system for your property.

Where can I get technical information about each solar hot water system?
To view the technical specifications of Solargain’s hot water range, click here.


Solar Hot Water - Operation

Solargain’s hot water systems can provide up to 90% of your hot water needs.
In fact, your solar hot water system will convert the sun’s heat at around 2/3 times the ambient temperature on a clear, sunny day depending on the type of system installed.

Though solar hot water systems will still work on most cloudy days, Solargain models are all fitted with a back-up gas or electric booster, so you’ll never run out of hot water.

Yes, in most overcast conditions your solar hot water system will continue to work. Evacuated tube systems are especially efficient in these less than perfect conditions. Very rarely are clouds thick and abundant enough to completely block solar radiation from the sun, especially in Australia.

In cases where cloud cover is particularly thick and light is scarce, your electric or gas booster will help heat your property’s water, bolstering the solar hot water system when it cannot provide enough power

Properties with flat roofs are still able to enjoy the benefits of solar hot water. If your roof is flat, we’ll raise your solar collectors so that they can access the full solar energy potential.

Your solar hot water system works hard during the day to heat water that’ll still be hot enough for use at night and all through to the next morning. The insulation in your hot water tank ensures that water temperature levels hardly drop, while your back-up gas or electric booster is always on standby if required.

It is essential that you choose an accredited solar hot water installer, such as Solargain, to fit your system. When installed and maintained correctly, solar hot water systems are exceptionally safe and reliable. There’s not too much that can go wrong with solar hot water systems, and when it does, we’re here to assist you.

Solargain’s solar hot water products in particular are manufactured to the strictest quality standards and are covered by generous warranties. We are also accredited with ISO 9001 and AS/NZS 4801 certification, highlighting our commitment to quality and safety.

Solar hot water systems are designed to withstand the toughest weather conditions. From blistering heat to freezing cold, including hail storms and more, they’re tough enough to last through almost anything.

The lifespan of your solar hot water system depends on how often it’s serviced, where it’s installed and how it’s used. Generally, solar hot water systems are expected to last well over 10 years, with reports in Australia of systems in operation for 20 years and longer.

Solargain’s solar hot water systems are covered by warranties spanning from 5 to 10 years and are made using strong, high-quality materials.

If you have home building insurance and your solar hot water system is listed on your policy, you should be covered in the event that it is damaged or stolen.
Of course, you should always double check with your insurance company first.


Solar Hot Water: Performance and Savings


As a general guide, households with 2-4 people should install a system between 250-280L, whereas households with 4-8 people need to consider systems ranging from 300-400L.

Hot water usage patterns should also be considered when choosing the size of the system you install. Speak to Solargain’s solar hot water specialists to find out more information.

Solar hot water offers Australian home owners amazing savings over the lifetime of their system. Savings vary from state to state, but the average family home can save as much as $900 a year on water heating bills.

Aside from saving on power bills, generous government rebates and incentives still exist. In most cases, these slash the upfront costs of switching to solar substantially.

Domestic water heating is a serious contribution to the overall pollution emitted from Australian homes. In fact, according to the Clean Energy Council, water heating accounts for 23% of total greenhouse gas emissions from most homes.

Solar hot water installation reduces this figure by as much as 90% and for every megawatt hour of electricity saved, one tonne of harmful CO₂ is avoided.

This depends on the initial cost of your system as well as your location and hot water usage. The benefit of solar hot water systems is that they begin to pay back your investment as soon as they are switched on. After you recover your initial investment, every dollar that you save is yours to keep.

For a more accurate idea about your solar hot water payback period, ask Solargain.

In most states, rebates are still available and can save you well over $1,000 off the initial purchase price of your system. Conditions apply, so make sure you speak to Solargain to find out what rebates are available in your region and if you’re eligible.


Solar Hot Water: Installation


Easy! First, get in touch will Solargain by calling 1300 73 93 55 or by using our online enquiry form. We’ll ask some questions to better understand your needs before recommending a solar hot water system suited to your circumstances.

If you require a home assessment, we’ll visit your property obligation-free, and if you’re not quite ready to purchase, we’ll provide you with a written quote for later use.

No deposit is required after you’ve ordered your system. You’ll be invoiced after the work is complete.

Solargain’s range of payment options are designed to fit in with your lifestyle and budget.

One way to pay is in full and up-front. We require no deposit and will only ask for payment after installation.

If you’d rather pay for your system gradually, Solargain’s flexible finance options may suit you. In conjunction with our financing partners at Ezi-Pay, you can choose a range of repayment schedules between 12-40 months (depending on your system).

For customers looking to really ramp up their savings, take advantage of Solargain’s hot water and solar PV bundles, allowing you to install and pay-off two unique energy saving solutions in one package.

Contact us to find out more about our various payment options.

We’ll arrange an installation date with you between three and seven working days.

In the case of an emergency hot water breakdown, Solargain also offers a swift service option. In most cases this service gets you reconnected with hot water in less than 24 hours.

Installation typically takes less than five hours and so you shouldn’t be without hot water for any longer than this.

Most roofs are well-equipped to handle the weight of a solar hot water system without the need for extra reinforcement. Rest-assured, Solargain will make sure that your roof is strong enough to support a solar hot water system before installation.

If your roof does require strengthening, we will notify you and present you with a number of options moving forward, and do everything we can to help you get your roof into a state where it can support your solar hot water system.


Solar Hot Water: Post Installation


To ensure the longevity, continued performance and safety of your solar hot water system, it’s recommended that you service it once every five years. 

Solargain has an expert service division and is here to assist you on this front as well.

Located on the side of the water tank, the PTR valve is an essential component of your solar hot water system. The PTR valve is designed to allow 3-5% of your total tank volume to discharge during heating. This allows for hot water expansion and also ensures that your system continues to run safely. 

If you notice that your PTR valve is leaking excessively during the day and night, call Solargain to have it checked as it may be faulty.

Cloudy or discoloured water indicates a problem with your cylinder and is the first sign that the internal lining of your hot water tank is deteriorating. If the colour of your household water has changed, it’s time to seriously consider replacing your system.

Chances are you don’t have a tempering valve installed with your solar hot water system. Installing a tempering valve will cap your hot water to a maximum of 50⁰C. This not only reduces your overall hot water energy consumption, but it helps avoid scalding during hot water use. 

Get in touch with Solargain to find out more about tempering valve installation.

Installing solar hot water is a fantastic way to start saving money on power bills and slashing your carbon footprint – but it’s only the beginning!

If you want to take your savings to the next level, consider installing water saving showerheads, and aiming to spend no longer than four minutes in the shower at a time. Showers (and baths) are typically responsible for the majority of hot water use in average homes.

To save even more money, consider installing a solar PV power system along with solar hot water, and take advantage of the sun’s energy to power your entire home.
For more energy saving tips and advice, visit our blog.


If you have any other questions please ask below.

To receive your quote as fast as possible, please supply your installation address so that Solargain can check the aerial photo of your roof.
To receive your quote as fast as possible, please supply your installation address so that Solargain can check the aerial photo of your roof.
To receive your quote as fast as possible, please supply your installation street, suburb and postcode so that Solargain can check the aerial photo of your roof.