Hot water systems

There are a range of hot water systems available in today's market.

Heat pump systems

Heat pump systems are more efficient than traditional electric hot water systems such as electric storage or instant hot water systems. Heat pump systems have a storage tank and work similar to your refrigerator. A heat pump pulls heat from the surrounding air and uses it to heat water. This makes it more efficient to run.

Consider changing to a heat pump if you have solar power or intend to install solar power in the future. You can offset some of the energy used by the heat pump with your solar system.

It's worth noting that some heat pump hot water systems can be louder than others to run.

There is currently no star rating system for heat pump water systems.

Solar hot water systems

Solar hot water systems are an efficient way to heat water. Depending upon the time of year, most of your water can be heated by free energy from the sun.

Solar hot water systems heat water using solar collectors mounted on your roof, which are either flat panels or glass tubes. The hot water is then stored in a tank, which can either be installed on the roof or on the ground.

Solar hot water systems need boosting from another energy source, such as gas or electricity. You can even retrofit a solar system to some existing hot water systems.

There is no star rating system for solar water heaters.

Electric systems

Electric hot water storage systems can be very costly to run. Systems under 250 litres usually run on peak electricity rates which makes them expensive to run. These are sometimes the only option for flats and smaller homes, especially when they need to be installed under kitchen benches or in cupboards. Larger units over 250 litres can run on off-peak or controlled load electricity tariffs and heat up overnight, which can make them cheaper to run.

Electric instantaneous systems are generally more efficient than electric storage heaters, and modern models have better temperature control than older models. These units require dedicated wiring due to the high currents involved, so can be more costly to install.

If you have solar power, you can offset some of the energy that electric hot water systems use.

There is no star rating system for electric storage or instant water heaters.

Gas systems

Instantaneous gas hot water systems, sometimes called 'continuous flow', heat only the water that you require and don’t have a storage tank. Instantaneous systems often require large gas pipes, which can increase the cost of installation.

Gas storage hot water heaters store hot water in a tank. Storage systems are usually less efficient than instantaneous systems because energy is lost through the walls of the tank. The size of the storage tank is important. If the tank is too small, you may find you run out of hot water. If the tank is too large, you will be paying to heat water that you don't need.

Gas hot water systems have a star rating, which helps compare your model to others on the market. A list of current models with star ratings is available from the Australian Gas Association: www.aga.asn.au/complete_product_directory.

Wood fuel systems

Wood fuel systems are occasionally used to heat water, often as part of heating the home. These are usually only found in rural areas where wood is plentiful. The performance of different wood fuelled systems can vary a lot. Efficiency is impacted by many factors, including the type and quality of fuel and the age and maintenance of the system. These systems require you to find, cut and store wood appropriately. It is important to manage the air quality of your home by operating the system efficiently as smoke can be unhealthy and inconvenient for you and your neighbours.

Page last updated: 14/10/24