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Solar powered hot water systems

Trust the Brisbane solar hot water specialists. We install, service and replace both roof-mounted and split solar hot water systems — quickly, compliant with regulations, and designed for long-term performance.

Solar hot water systems are available in two distinct designs

Solar hot water systems come in two primary formats—roof-mounted and split—with a range of tank capacities and configurations to match different homes, climates and siting requirements. Aside from cutting your environmental footprint, the main benefit is the noticeable reduction in energy bills. Electric hot water units operate like a kettle, using an electric element, and in Queensland they’re typically offered in 1.8kW, 2.4kW and 3.6kW sizes (the 4.8kW elements are rarely used because of their high power demand). These element ratings are standard across leading brands such as Rheem, Dux, Vulcan, AquaMAX and Rinnai. Bear in mind that element size does not affect the system’s efficiency rating. A 1.8kW element draws half the power of a 3.6kW element but will require roughly 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 tanks coated with vitreous enamel and safeguarded by a sacrificial anode, or Stainless steel tanks for greater longevity. Copper-style water heaters are no longer manufactured.

Need a Solar Hot Water System Installed Quickly? Brisbane Hot Water Heaters Can Help!

Roof-mounted thermosyphon solar hot water systems.

Roof-Mounted Solar Hot Water Systems

This is the classic style of solar hot water installation, where both the storage tank and the solar collectors sit on the roof. These setups have been common in Australia for decades and remain a reliable method for heating household water.

How They Work

The system operates using simple thermosyphon principles:

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

When the water in the collectors warms, it becomes buoyant and returns to the storage tank.

This natural circulation keeps replenishing the tank with hot water.

Modern Improvements

Older units often expelled excess water through the pressure and temperature relief valve during overheating. Contemporary thermosyphon models incorporate a flow control valve that limits circulation once water reaches about 60°C.

That reduces unnecessary water loss, though it can mean the system holds less very hot water than older designs.

On very hot days you may sometimes hear a rumbling when taps are opened; this is caused by superheated water moving through the collectors as pressure drops.

Tank & Collector Options

Collector size varies by manufacturer, offering different levels of solar gain.

Evacuated tube collectors are generally not recommended in Queensland because they can generate excessive solar gain and risk boiling off water for much of the day; they suit cooler, less equatorial climates better.

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

Considerations

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

A filled storage tank can exceed 500kg, imposing a substantial load on the roof structure.

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

Call Brisbane Hot Water Heaters on 1300 218 122 for clear, local advice on which solar hot water system and installation will best suit your Brisbane home.

Split-system, ground-mounted solar hot water systems

A split solar hot water system keeps the storage cylinder at ground level while only the solar collectors sit on the roof. The collectors may 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 cylinders typically come in sizes such as 250L, 315L and 400L.

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

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

This process transfers heat from the collectors to the tank, and natural convection causes the hottest water to rise to the top.

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

Build & installation

Copper flow and return lines are essential to cope with high temperatures.

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

Performance

Collector temperatures can reach up to around 120°C, and some systems will allow storage tanks to heat to about 75°C.

Once the tank hits its set temperature, water will stay in the collectors until demand lowers the tank temperature enough for the circulation to restart.

Why quality matters

Selecting a trusted brand is important. Many low-cost imports use inferior components that create significant problems and unexpected expenses for homeowners. The extra cost for a reputable system is small compared with the long-term reliability and peace of mind.

Contact Brisbane Hot Water Heaters on 1300 728 122 for straightforward, impartial advice on the right solar hot water system for your Brisbane home.

Flat-panel solar collector

Flat plate collectors are the most widely used solar hot water panels across Australia and perform well in almost any climate or setting. How they work Each panel contains a copper manifold with flat plates finished in black powder-coat to maximise heat absorption. As water moves through the copper pipes, heat is transferred either by: Thermosyphon circulation (in roof-mounted systems that rely on the natural rise of hot water), or A circulation pump (in split systems where the storage tank is at ground level). The collectors are sealed behind toughened glass and set in a fully insulated frame to trap heat and deliver reliable long-term performance. Efficiency Flat plate panels can produce warmth even without direct sun. On cloudy days they can still reach roughly twice the surrounding air temperature — for instance, with an ambient 26°C, panels may heat water to about 52°C. Installation The required number of panels is determined by the size of your storage tank. Typically two to three panels are needed to suit the capacity of standard hot water systems. Brisbane Hot Water Heaters offers local advice on system selection, installation and repairs for hot water systems — gas and electric — and can arrange a Brisbane plumber to assess your needs.

Evacuated-tube solar collectors

Evacuated tube systems consist of multiple glass tubes, each housing a copper heat-transfer rod and fluid. The tubes fit into a top manifold on the collector, where solar energy is captured and conveyed to the storage tank. System design They come in sets of 12, 18, 24 or 32 tubes to match different tank capacities and installation needs. These collectors are highly efficient — tube surfaces can reach around 250°C in strong sunlight. Suitability They were developed for European-style climates with weaker sunlight and lower solar angles. They perform well in cooler parts of Australia such as southern NSW, Victoria, South Australia and southern WA. In Queensland, though, they often produce too much heat, causing overheating, increased water loss and gurgling or rumbling as water boils inside the tubes. Considerations Only a small number of suppliers continue to offer evacuated tube systems in Australia. They typically cost about $1,000 more than flat plate panels and do not provide notable advantages in Queensland’s climate. For most Brisbane homes, we don’t recommend evacuated tubes; flat plate hot water systems generally give better value, reliability and performance for local conditions.

Call Brisbane Hot Water Heaters on 1300 728 122 for professional, impartial, fact-driven guidance from a local Brisbane plumber with over 20 years serving South East Queensland.

You can call us on 0413 861 166 outside regular hours, including evenings and weekends.

At Brisbane Hot Water Heaters, we hold a broad selection of solar hot water systems on-site so we can provide prompt installation. By keeping the leading models in stock, we avoid delivery waits—meaning your new hot water system can be fitted without unnecessary delays.

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