Buyers Guide – Hot Water

Rinnai offers a range of hot water solutions to suit different Australian homes. These options include

• Gas Continuous Flow for endless hot water on demand.

  The Rinnai Infinity Gas Continuous Flow system heats water instantly as it passes through the unit, eliminating the need for a storage tank. Powered by natural gas or LPG, it delivers a continuous supply of hot water on demand, making it ideal for households of all sizes. When a hot water tap is turned on, the system automatically ignites and heats the water to the set temperature, providing efficient and reliable hot water whenever it's needed.

• Electric Continuous Flow for gas-free properties.

  The Rinnai Efinity is a fully electric, continuous flow hot water system that heats water instantly as it flows through the unit — without the need for a storage tank. It operates using 3-phase power and is available in high-capacity models, making it suitable for homes with high hot water demand. When a hot water tap is opened, the system automatically activates and begins heating water to the set temperature.

• Heat Pump Systems for the lowest running costs and carbon footprint.

  Heat Pump hot water units operate using the same technology as reverse cycle air conditioners. They use a refrigerant gas that absorbs heat from the surrounding air. Through a reverse cycle refrigeration process, this heat is transferred to the water via a heat exchanger. The system continues circulating until the water in the storage tank reaches the set temperature. This method is highly energy-efficient because it uses ambient air to heat water, even in cooler conditions, without relying solely on electric heating elements.

• Storage Tanks for straightforward, budget-friendly installations.

  A Storage hot water system heats and stores water in an insulated tank, ensuring hot water is readily available throughout the home. Available in electric or gas models, and in a range of sizes to suit different household needs. These systems automatically heat and maintain the water at a set temperature, reheating as hot water is used. Storage systems are a reliable and familiar hot water solution, offering consistent performance for everyday hot water demand.

• Solar Hot Water for households maximising renewable energy.

  A Solar hot water system uses rooftop solar collectors to heat water stored in a tank, with a gas or electric booster providing additional heating when needed. The two main types are close-coupled systems, where the tank and collectors are mounted together on the roof, and split systems, where the tank is located on the ground and a pump circulates water to and from the rooftop collectors.

The right choice depends on your household size, gas access, budget, and energy goals.

Sizing depends on your system type. Storage and heat pump systems are sized by tank capacity against household size, ranging from 180L for 3–4 people up to 400L for larger households of 7–8. Continuous flow systems are sized differently, based on how many showers or outlets might run at once, with climate also playing a role since colder incoming water needs more heating capacity. A typical family of four suits a 250L to 315L storage or heat pump system, or a mid-range continuous flow model sized to simultaneous usage.

Gas Continuous Flow

• Infinity B12: Warm/Cool climate → 1 shower outlet.

• Infinity B16: Warm/Cool climate → 1 shower outlet.

• Infinity B20: Warm climate → 1-2 shower outlets | Cool climate → 1 shower outlet.

• Infinity B26: Warm climate → 1-3 shower outlets | Cool climate → 1-2.5 shower outlets.

• Infinity 28i: Warm climate → 1-3 shower outlets | Cool climate → 1-2.5 shower outlets.

• Infinity 32: Warm climate → 2-4 shower outlets | Cool climate → 2-3 shower outlets.

Electric Continous Flow

• Efinity 14kW: Shower outlets → 1 | Sink outlets → 1 | Basin outlets → 2.

• Efinity 19kW: Shower outlets → 1 | Sink outlets → 2 | Basin outlets → 3.

• Efinity 29kW: Shower outlets → 2 | Sink outlets → 2 | Basin outlets → 4.

Heat Pump Systems

• Models Enviroflo S 5.0kW: 250L → up to 5 people | 315L → up to 6 people.

• Enviroflo S 7.0kW: 250L → up to 5 people | 315L → up to 6 people | 400L → up to 8 people.

• Enviroflo AR Series: 300L → up to 6 people | 340L → up to 7 people.

• Enviroflo GR Series: 215L → up to 4 people | 280L → up to 5 people | 300L → up to 6 people.

• Enviroflo A Series: 180L → up to 3 people.

• Enviroflo 265L: 265L → up to 5 people.

• Hotflo Plus 250L: 250L → up to 5 people.

Storage Tanks
As a general guide, you’ll need about 50 litres of hot water per person, plus an extra 50 litres to cover those busy times when everyone’s using hot water at once.

• 1–2 people → around 125L.

• 3–4 people → around 250L.

• 5 or more people → 315L or larger.

Government Rebates

Several government schemes can reduce the upfront cost of upgrading to a Rinnai hot water system, particularly heat pump and solar options. These vary by state, and in most cases stack with each other. Please note this is a general overview only. Your local dealer can confirm exactly what you're eligible for and apply any relevant discount to your quote.

Solar Victoria Hot Water Rebate (VIC)

Victorian households can receive a rebate of up to $1,000 on an eligible heat pump or solar hot water system, or up to $1,400 if the product is locally made. Several Rinnai heat pump models are on the current locally made eligible list. The rebate is a 50% discount on the purchase price, calculated after other discounts like STCs, and requires an existing system at least 3 years old plus a household income cap.

• Read more on Solar Victoria Hot Water Rebate >

Victorian Energy Updates (VIC)

Separately to the Solar Victoria rebate, VEU offers an upfront discount through accredited providers when replacing an inefficient electric or gas system with a heat pump or solar-boosted system, up to $630–$910 depending on what's being replaced. Combining VEU with the Solar Victoria rebate can save Victorian households up to $1,960 on an eligible system.

• Read more about the VEU Hot Water System discounts >

Energy Saving Scheme (NSW)

NSW households and small businesses can access an upfront installer discount of up to $640 when replacing an electric water heater with a heat pump, or up to $330 when replacing gas with a heat pump. The actual discount varies by installer and system, so it's worth comparing quotes from a few accredited providers.

• Read more about NSW Hot Water Upgrade Incentives >

Small-scale Technology Certificates – STCs (Federal)

Available nationwide, STCs apply to eligible solar hot water systems and air source heat pumps and can be claimed directly or assigned to a registered agent for an upfront discount on the purchase price. The value depends on your location and system size.

Official Government Information

• Solar Water Heaters and Air Source Heat Pumps

• Rooftop Solar