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Solar hot water systems

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

There are two main types of solar hot water systems.

Solar hot water systems come in two primary configurations—roof-mounted and split—offering a range of tank capacities and layouts to match different homes, climates and siting requirements. Aside from the environmental benefit of lower energy consumption, the main perk is the noticeable reduction in your power bills. Electric hot water units operate similarly to a kettle, using a heating element. In Queensland they commonly come in 1.8kW, 2.4kW and 3.6kW ratings (the 4.8kW elements are rarely used because of their high power demand). These element sizes are industry-standard across major brands such as Rheem, Dux, Vulcan, AquaMAX and Rinnai. Bear in mind that the element size does not affect the system’s efficiency rating. A 1.8kW element consumes half the power of a 3.6kW element but will require roughly twice the time to raise the same volume of water to an identical temperature. Contemporary electric hot water systems are constructed with either: Mild steel tanks coated with vitreous enamel and protected by a sacrificial anode, or Stainless steel tanks for greater longevity. Traditional copper-style water heaters are no longer manufactured.

Need a Solar Hot Water System Installed Quickly? We’re Here to Help!

Roof-mounted thermosyphon solar hot water systems.

Roof-mounted solar hot water systems

This is the classic solar configuration where the storage tank and solar collectors are both fitted on the roof. These setups have been common in Australia for decades and continue to be a reliable method of heating household water.

How they work

The system relies on basic thermosyphon principles:

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

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

This natural circulation keeps replenishing the tank with hot water without pumps.

Modern improvements

Older units would often expel excess water via the pressure and temperature relief valve when they overheated. Contemporary thermosyphon designs now incorporate a flow control valve that limits circulation once water reaches about 60°C.

This reduces unnecessary water discharge, though it can also mean less total hot water is stored compared with older models.

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

Tank and collector options

Collectors are available in various sizes by brand, offering different levels of solar gain.

Evacuated tube collectors are generally not advised for Queensland, as they can generate excessive solar gain and risk boiling off water for much of the day; they’re better suited to cooler, more southerly areas.

Storage tanks come in stainless steel or vitreous enamel–lined mild steel variants.

Considerations

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

A filled storage tank can weigh in excess of 500 kg, which is a substantial load for the roof structure.

Many homeowners also prefer alternatives because the large tank is prominently visible.

Call Nambour Hot Water on 1300 218 122 for clear, professional advice about which solar hot water system, gas and electric options, installation or repairs will suit your home.

Ground-mounted split-system solar hot water heaters

A split solar hot water system places the storage tank at ground level while only the solar collectors sit on the roof. Collectors may be flat panels or evacuated tubes—however evacuated tubes are generally unsuitable for Queensland’s climate because they can overheat, lose water through boiling and cause unnecessary rumbling sounds.

How they work

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

A temperature sensor at the collectors and another at the tank measures the differential.

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

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

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

Build & installation

Copper flow and return piping is recommended to cope with high temperatures.

At Nambour Hot Water, we run these pipes in one 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 120°C, and some systems allow storage tanks to climb as high as 75°C.

Once the tank meets its set temperature, water will remain in the collectors until household usage lowers the tank temperature enough to restart circulation.

Why quality matters

Selecting a trusted brand is essential. Many low-cost imports with inferior components have led to significant failures and extra expense for homeowners. The extra cost for a reliable system is small compared with long-term performance and peace of mind.

Contact Nambour Hot Water on 1300 728 122 for impartial, expert advice on the right solar hot water system, installations and repairs — gas and electric options available.

Flat plate solar collector

Flat plate collectors are the most widely used type of solar hot water panel in Australia and perform well in nearly any climate or location. How they operate Each collector contains a copper manifold fitted with flat plates that are powder-coated black to capture maximum heat. As water moves through the copper tubing, temperature is raised either by: Thermosyphon circulation (roof-mounted systems that rely on the natural rise of hot water and fall of cold), or A circulation pump (split systems where the storage tank sits on the ground). The collectors are sealed behind toughened glass within a fully insulated frame, which traps heat and provides durable, long-term performance. Efficiency Flat plate panels are able to produce heat even without full sun. On cloudy days they can still lift water temperature to around twice the ambient air temperature—for example, when the air is 26°C the panels may heat water to about 52°C. Installation Panel quantity is determined by your storage tank capacity. Typically, two to three panels are required to suit the size of common hot water storage tanks. Nambour Hot Water provides installation and repairs for hot water systems, including gas and electric and solar options, and can advise on the right number of panels for your property.

Evacuated-tube solar collectors

Evacuated tube hot water systems consist of multiple glass tubes, each housing a copper heat pipe filled with a thermal transfer fluid. The tubes slot into a top-mounted manifold on the collector, where solar energy is captured and passed to the storage tank.

System design

These collectors are offered in sets of 12, 18, 24 or 32 tubes, chosen to match tank capacity and site installation needs.

High efficiency—when exposed to full sun the tube surfaces can reach temperatures approaching 250°C.

Suitability

They were originally developed for cooler, European-style climates with lower solar angles and weaker sunlight.

They perform well in Australia’s cooler regions such as southern NSW, Victoria, South Australia and southern WA.

In Queensland, however, their high efficiency often causes overheating, increased water loss and boiling-related noises in the tubes.

Considerations

Very few Australian suppliers continue to carry evacuated tube systems.

They generally cost about $1,000 more than flat plate collectors while offering little advantage in Queensland’s conditions.

For most Nambour homes, we don’t recommend evacuated tubes; flat plate hot water systems typically provide better value, reliability and performance locally for both gas and electric installations and repairs.

Call Nambour Hot Water on 1300 728 122 for trusted, impartial, fact-led guidance from a local Nambour plumber with over 20 years’ experience serving South East Queensland.

You can call our Nambour plumber outside business hours and on weekends on 0413 861 166

At Nambour Hot Water, we keep a broad selection of solar hot water systems on hand for prompt installation. By carrying the key models we supply, there’s no waiting for deliveries—your new hot water system can be fitted quickly without unnecessary delays.

We also provide Easy Payment Plans to help spread the upfront cost. With terms from 1 to 3 years and fortnightly repayments following a small deposit, your repayments can be similar to the amount you’re already saving on your electricity bills.