Solar hot water systems
Solar hot water systems are available in two main configurations
Require fast solar hot water installation? Gympie Hot Water can sort it quickly and professionally.
Roof-mounted thermosyphon solar hot water systems.
Roof-mounted solar hot water systems
This is the classic solar arrangement where both the storage tank and the solar collectors sit on the roof. It’s a long-established method in Australia and continues to be a reliable way to heat household water.
How they work
The system operates using simple thermosyphon principles:
Cooler water drops to the lowest point in the tank and flows into the solar collectors.
When the water warms in the collectors it becomes buoyant and returns to the storage tank.
This natural circulation repeats, keeping the tank topped up with heated water.
Modern improvements
Older designs often discharged excess water through the pressure and temperature relief valve during overheating. Current thermosyphon models typically include a flow control valve that limits circulation once water reaches about 60°C.
This reduces unnecessary water loss, although it can mean slightly less stored hot water than older versions.
On very hot days these systems can occasionally make a rumbling sound when taps are opened, caused by superheated water moving through the collectors as pressure drops.
Tank and collector options
Collectors vary in size by manufacturer, delivering different levels of solar gain.
Evacuated tube collectors are generally not recommended in Queensland because they can produce excessive solar gain and risk boiling off water for much of the day; they are better suited to cooler, less equatorial climates.
Storage tanks are offered in stainless steel or vitreous enamel–lined mild steel.
Considerations
The primary downsides of roof-mounted systems are visual impact and weight:
A filled storage tank can exceed 500 kg, creating a significant load on the roof structure.
Many homeowners also dislike the look of a large tank visible on the roof.
Call Gympie Hot Water on 1300 218 122 for clear, professional advice on which solar hot water system — installation, repairs or upgrades — is right for your home. We’re your local Gympie plumber specialising in hot water systems, gas and electric solutions.
Ground-mounted split-system solar hot water units
A split solar hot water system places the storage tank at ground level while only the solar collectors sit on the roof. The collectors may be flat panels or evacuated tubes — however, evacuated tubes are generally unsuitable for Queensland’s conditions because they can overheat, lose water to boiling and produce unnecessary rumbling sounds.
How they work
Storage tanks typically come in 250L, 315L and 400L capacities.
A temperature sensor at the collectors and another at the tank tracks differences in heat.
When the collectors are about 10°C warmer than the tank, a small circulation pump (usually 25W or less) kicks in, moving roughly 2–3 litres per minute through the collectors.
That process transfers heat from the collectors back into the tank, where natural convection causes the hottest water to rise to the top.
The pumps are quiet and use very little electricity — most consume less power in a day than a microwave clock.
Build & installation
Copper flow and return pipes should always be used to cope with high temperatures.
At Gympie Hot Water, we run these pipes in a single continuous length with no joints or fittings inside the roof cavity and wrap them in 25mm high-temperature, UV-rated insulation to reduce heat loss.
Performance
Collector temperatures can reach up to 120°C, and some systems allow tank temperatures to climb to around 75°C.
Once the tank hits its target temperature, water stays in the collectors until draw-off lowers the tank temperature enough to restart circulation.
Why quality matters
Selecting a trusted brand is essential. Many low-cost imports use inferior components that create major problems and added expense for homeowners. The extra cost for a dependable system is small compared with long-term reliability and peace of mind.
Contact Gympie Hot Water on 1300 728 122 for straightforward, impartial advice on selecting the right solar hot water system for your home.
Flat-panel solar collector
Evacuated Tube solar collectors
Evacuated tube systems consist of multiple glass tubes, each housing a copper heat pipe filled with a thermal transfer fluid. The tubes fit into a top-mounted manifold on the collector, where solar heat is taken up and conveyed to the storage tank.
System design
They are offered in sets of 12, 18, 24 or 32 tubes, with the choice driven by the tank capacity and installation needs.
Highly efficient — in strong sunlight the tube surfaces can reach temperatures up to around 250°C.
Suitability
These systems are mainly developed for European-style climates with weaker sun and lower solar angles.
They perform well in cooler parts of Australia such as southern NSW, Victoria, South Australia and southern WA.
In Queensland, however, evacuated tubes can be overly efficient, which often causes overheating, increased water loss and boiling noises from the tubes.
Considerations
There are only a small number of suppliers still offering evacuated tube systems in Australia.
They generally cost about $1,000 more than flat plate collectors and don’t provide notable advantages in Queensland’s climate.
For most Gympie homes, we don’t recommend evacuated tubes — flat plate hot water systems give superior value and performance in local conditions.
Call Gympie Hot Water on 1300 728 122 for trusted, impartial, evidence-based guidance from a local Gympie plumber team with over 20 years serving South East Queensland.
You can call Gympie Hot Water any time — evenings and weekends — on 0413 861 166
At Gympie Hot Water, we carry a broad selection of solar hot water systems on hand for prompt installation. By keeping the key models we supply in stock, you won’t have to wait for deliveries—your new hot water system can be fitted quickly with minimal delay.
We also provide Easy Payment Plans to help spread the upfront cost. With terms from 1 to 3 years and fortnightly repayments after a small deposit, your repayment amounts can be similar to the savings you’ll see on your electricity bills.
Gympie Hot Water provides and fits solar hot water systems throughout Gympie—quick, compliant and designed for long-term performance.
The reviews shown here are genuine customer testimonials gathered from Google, Facebook and other independent review platforms — not fabricated, self-written endorsements you often see on websites
