The most efficient hot water heater in Australia would be a heat pump hot water system. Heat pump hot water systems are highly energy-efficient as they use ambient air to heat the water rather than generating heat directly.
Heat pump hot water systems work by extracting heat from the air and transferring it to the water, which makes them more energy-efficient than traditional electric or gas hot water systems.
Heat pump hot water systems typically have an energy efficiency rating of between 2.8 and 4.0, which means they can reduce your hot water energy consumption by up to 65% compared to a standard electric hot water system. Some popular brands of heat pump hot water systems in Australia include Rheem, Bosch, and Stiebel Eltron.
It’s important to note that while heat pump hot water systems are highly energy-efficient, they can be more expensive to purchase and install compared with traditional hot water systems. However, the long-term energy savings can make up for the initial cost, and there may be rebates or incentives available to help offset the cost of installation.