Solar hot water systems are designed to harness free energy from the sun to heat your water. Over time, they offer some of the biggest savings on household energy bills — especially in sunny regions like Brisbane. While the upfront cost can be higher, the long-term payoff in efficiency, sustainability, and rebates makes them a strong contender for both homes and investment properties.
What Is a Solar Hot Water System?
Solar hot water systems use rooftop collectors to heat water using direct solar energy. That heated water is stored in a tank for use throughout the day. Depending on the system design, backup heating is provided via gas or electricity to maintain temperature during cloudy periods.
How It Works
- Cold water flows into the solar collector panel, usually mounted on the roof
- Sunlight heats the water as it passes through the collector
- The warmed water rises into the storage tank
- Hot water is stored and used as needed
- A booster (not shown in this diagram) ensures water stays hot even on cold or overcast days
- A sacrificial anode helps protect the tank from corrosion
- The pressure relief valve prevents over-pressurisation
The Benefits of Solar Hot Water
When correctly installed, solar systems can reduce water heating bills by up to 80%. Key benefits include:
- Major long-term savings on energy costs
- Federal and state rebates available to reduce installation cost
- Environmentally friendly — lower carbon footprint
- Ideal for households with high daytime water usage
- Works well with solar PV systems for added efficiency
- Quiet operation with low maintenance requirements
In Queensland, solar hot water is a logical choice — there’s sun most of the year, and energy prices continue to climb.
Types of Solar Hot Water Systems
- Roof-Mounted Systems
- Storage tank and collectors are both on the roof
- Uses thermosiphon action (hot water rises naturally)
- Simple, no pumps required
- Split Systems
- Collectors on the roof; tank on the ground
- Pump moves water between tank and collectors
- Easier servicing and less roof weight
Both systems can be boosted with gas or electricity.
Signs It’s Time for an Upgrade or Repair
Even solar systems need upkeep. Common issues include:
- Water not heating effectively, especially during sunny days
- Leaks around roof pipes or tank valves
- Noisy or constantly running booster
- Panel damage from debris or hail
- Sediment build-up in older systems
Routine maintenance keeps efficiency high and extends the system’s life.
Why You Need a Qualified Plumber
Solar hot water installation is more complex than other systems. A licensed plumber ensures:
- Panels are positioned and angled correctly for year-round performance
- Pipework is safely routed and pressure-tested
- Boosters are correctly integrated and protected
- System complies with government rebate eligibility
- Maintenance points are accessible
At RJT Plumbing and Gas, we install, service, and repair all types of solar hot water systems — including older models.
Looking for a Different Option?
We’ve broken down the key differences between all major systems. Compare here:
- Electric Storage Hot Water Systems
- Gas Storage Hot Water Systems
- Continuous Flow (Tankless) Systems
- Heat Pump Hot Water Systems
Every home is different. We’ll help you make the right choice based on household needs and budget.
Book a Solar System Inspection or Quote
Whether you’re upgrading an older unit or installing solar for the first time, RJT Plumbing & Gas can guide you through your options and maximise your rebate eligibility.
Contact us today for solar hot water servicing, replacement, or new installation in Brisbane and surrounding areas.
