Lifetime quality workmanship guarantee

Solar hot water systems

Trust the Sunshine Coast solar hot water specialists. We install, service and replace both roof-mounted and split solar hot water systems — quickly, to code and designed for longevity.

Solar hot water systems are available in two distinct designs

Solar hot water systems come in two primary configurations — roof-mounted and split — and offer a range of tank capacities and layouts to suit different dwellings, climates and site conditions. Besides the environmental upside of cutting energy consumption, the main benefit is noticeable reductions in your electricity bills. Electric hot water units operate similarly to a kettle, using a heating element. On the Sunshine Coast, common element ratings are 1.8kW, 2.4kW and 3.6kW, with the larger 4.8kW elements rarely used because of their heavy power demand. These element sizes are standard across major manufacturers such as Rheem, Dux, Vulcan, AquaMAX and Rinnai. Bear in mind that element size doesn’t alter the system’s efficiency rating. A 1.8kW element draws half the power of a 3.6kW element, but will require about twice the time to heat the same volume of water to the same temperature. Contemporary electric hot water systems are constructed with either: Mild steel cylinders coated with vitreous enamel and safeguarded by a sacrificial anode, or Stainless steel cylinders for greater longevity. Traditional copper-style hot water heaters are no longer manufactured.

Need solar hot water installed quickly? We’re Sunshine Coast water heater experts and can help!

Roof-mounted thermosyphon solar hot water systems.

Roof-mounted solar hot water systems

This is the classic solar hot water arrangement, with both the storage tank and solar collectors fitted on the roof. These setups have a long history in Australia and continue to be a reliable method of heating household water.

How they work

The system relies on simple thermosyphon principles:

Cooler water drops to the lowest part of the tank and flows down into the solar collectors.

As the water warms in the collectors it becomes lighter and rises back up into the storage tank.

That natural circulation runs continuously, replenishing the tank with heated water.

Modern improvements

Older units often discharged excess water through the pressure and temperature relief valve when temperatures climbed. Contemporary thermosyphon models now include a flow control valve that limits circulation once water reaches about 60°C.

This reduces unnecessary water loss, although it can mean the system stores slightly less hot water than older designs.

On very hot days these systems can sometimes make a rumbling sound when taps are opened, caused by superheated water moving through the collectors as pressure changes.

Tank and collector options

Collectors vary in size by manufacturer, delivering different amounts of solar gain.

Evacuated tube collectors are generally not advisable on the Sunshine Coast because they can produce excessive solar gain and risk boiling off water for much of the day. They suit cooler, less sun-intense regions.

Storage tanks are offered in stainless steel or vitreous enamel-lined mild steel.

Considerations

The primary downsides of roof-mounted systems are their weight and visual impact:

A full storage tank can weigh in excess of 500 kg, imposing a substantial load on the roof structure.

Many homeowners also dislike the look of a large tank mounted on the roof.

Call Sunshine Coast Water Heaters on 1300 218 122 for clear, expert advice about which solar hot water system, installation or repairs will best suit your home. Our Sunshine Coast plumber team specialises in hot water systems, gas and electric options.

Split-system, ground-mounted solar hot water units

A split solar hot water system locates the storage tank at ground level while only the solar collectors are installed on the roof. The collectors can be flat plate panels or evacuated tubes—however evacuated tubes are generally unsuitable for Queensland’s conditions because they can overheat, lose water through boiling and produce avoidable rumbling noises.

How they work

Storage tanks commonly come in 250L, 315L and 400L capacities.

A temperature sensor at the collectors and in the tank measures the difference in heat.

When the roof panels are around 10°C warmer than the tank water, a small circulation pump (typically 25W or less) starts, moving roughly 2–3 litres per minute through the collectors.

This process transfers heat from the collectors into the tank, with natural convection causing the hottest water to rise to the top.

The pumps are quiet and use very little power—often consuming less energy per day than the display on your microwave.

Build & installation

Copper flow and return pipework should always be specified to cope with high temperatures.

At Sunshine Coast Water Heaters, we run these pipes in a single continuous length with no joints or fittings inside the roof cavity, and insulate them with 25mm high-temperature, UV-rated insulation to reduce heat loss.

Performance

Collector temperatures can reach up to 120°C, and some configurations allow tank temperatures to climb to around 75°C.

Once the tank hits its set temperature, water will remain in the panels until demand lowers the tank temperature enough to trigger the circulation again.

Why quality matters

Selecting a trusted brand and quality components is essential. Low-cost imports with inferior parts have led to significant failures and unexpected expenses for homeowners. The extra cost for a dependable system is minor compared with the ongoing reliability and peace of mind.

Call Sunshine Coast Water Heaters on 1300 728 122 for straightforward, impartial advice about the best solar hot water system for your home.

Flat-panel solar collector

Flat plate collectors are the most widely used type of solar hot water panel across Australia and perform well in almost any climate or location. How they work Each collector houses a copper manifold with flat plates that are powder‑coated black to maximise solar heat absorption. As water travels through the copper piping, heat is transferred by either: Thermosyphon circulation (in roof‑mounted systems, utilising the natural rise of hot water and fall of cold), or A circulation pump (in split systems where the storage tank sits at ground level). The collectors are sealed behind toughened glass within a fully insulated frame, trapping heat and providing durable, long‑term performance. Efficiency These panels can produce useful heat even without direct sun exposure. On cloudy days they can still reach about twice the ambient air temperature — for example, with an air temperature of 26°C the panels may heat water to roughly 52°C. Installation The number of panels required is determined by your storage tank size. Typically two to three panels are needed to match the capacity of common hot water storage systems. Sunshine Coast plumber — Sunshine Coast Water Heaters offers expert advice, installation and repairs for gas and electric hot water systems as well as solar hot water systems.

Evacuated tube solar collectors

Evacuated tube systems consist of multiple glass tubes, each housing a copper heat pipe charged with a heat-transfer liquid. The tubes sit in a top-mounted manifold on the collector, where solar energy is captured and conveyed to the storage cylinder. System design These systems come in sets of 12, 18, 24 or 32 tubes, selected to match the tank capacity and the specifics of the installation. Extremely efficient — under full sun the tube surfaces can reach temperatures around 250°C. Suitability They were developed for cooler European-style climates, where sunlight intensity is lower and sun angles are more oblique. They suit cooler parts of Australia such as southern NSW, Victoria, South Australia and southern WA. In Queensland, though, they are frequently overly efficient, which can cause overheating, excessive water loss and boiling-related rumbling within the tubes. Considerations Only a small number of suppliers still offer evacuated tube systems in Australia. They generally cost about $1,000 more than flat plate collectors and do not provide notable advantages in Queensland’s climate. For most Sunshine Coast homes, we advise against evacuated tubes; flat plate hot water systems typically give better performance and value locally.

Call Sunshine Coast Water Heaters on 1300 728 122 for professional, impartial, evidence-based guidance from a local Sunshine Coast plumber with over 20 years serving South East Queensland.

You can call our Sunshine Coast plumber any time, including weekends and after hours, on 0413 861 166

At Sunshine Coast Water Heaters, we hold a broad selection of solar hot water systems on-site for prompt installation. Keeping the leading models in stock means you won’t wait for deliveries—your new hot water system can be fitted quickly and without delay.

We also provide Easy Payment Plans to help spread the upfront cost. With terms from 1 to 3 years and fortnightly payments following a modest deposit, your repayments can be comparable to the energy savings you’ll see on your electricity bills.