Rinnai INFINITY A-Series external gas continuous flow water heaters

Only on when you need hot water

Rinnai INFINITY A-Series gas continuous flow water heaters

The Rinnai INFINITY A-Series are continuous flow hot water systems for residential applications. These water heaters produce endless hot water, and unlike electric cylinders, are energy efficient as they are only on when you need hot water.

Five models to choose from depending on your hot water needs (A16, A20, A24, A26*). Use the Rinnai INFINITY model selector in the 'Suitable for' tab to work out which model is suitable for you.

* Model numbers represent hot water capacity, for example the A26 produces 26 litres of hot water per minute at a 25 degree Celcius rise.

Suitable for:
• external residential applications
• mains and medium pressure systems

Hard or acidic water will need to be treated to use this product.

Gas type
Available for Natural Gas or LPG. Specify gas type at the time of purchase.

General clearances
The following diagram has been provided to assist you in determining where (and if) an external continuous flow water heater can be positioned. If in doubt, prior to purchase, consult a licensed gasfitter.

Basic clearances for Rinnai INFINITY A-Series external water heaters

Clearance below eaves, balconies, and other projections is 300 mm.
* Rinnai recommend 1.5 m to give enough clearance for the pipe work, and to safely expel the flue gases.

Rinnai INFINITY model selector

Rinnai INFINITY model selector table
If the maximum water flow for your household exceeds what is listed in the table for your region, two INFINITY units may be required. Please contact your local gasfitter for a recommendation.





Energy Star Rating


Factory preset temp. 55 °C
Model code and REU numbers
  • A16: INFA16N/L - REU-A1620WG-ZK
  • A20: INFA20N/L - REU-A2024WG-ZK
  • A24: INFA24N/L - REU-A2426WG-ZK
  • A26: INFA26N/L - REU-A2626WG-ZK
Hot water capacity
  • A16: 2.1-16 L/min
  • A20: 2.5-20 L/min
  • A24: 2.1-24 L/min
  • A26: 2.1-26 L/min
Input and output A16: Input: 16.3-124 MJ/h, output 27.4 kW
A20: Input: 19.9-156 MJ/h, output 33.9 kW
A24: Input: 16.3-184 MJ/h, output 41.4 kW
A26: Input: 16.3-199 MJ/h, output 44.2 kW
Exhaust system Forced flue
Frost protection Fitted as standard. Frost protection operates automatically, as long as the appliance is connected to the electrical power supply, by activating when the temperature inside the unit drops below 3.5 °C, and turns off once the temperature inside the unit reaches 7 °C.
Ignition system Direct electronic ignition
Injector sizes A16: NG: 0.9, 1.50, LPG: 0.71, 1.09
A20-A26: NG: 1.08, 1.80, LPG: 0.73, 1.12
Line pressure (min.) NG: 1.13 kPa, LPG 2.75 kPa
Line pressure (max.) 3.5 kPa (maximum standing pressure under abnormal intermittent conditions is 5.0 kPa).

In the case of commercial metering, (i.e. 35-37 kPa coming in), there may be a requirement to regulate the incoming pressure down).
Power consumption

Normal: 47 W (A16), 58 W (A20), 56 W (A24), 66 W (A26)

Standby: 2 W

Automatic Frost Protection: 68 W 

Pressure relief

Valve opens at 2060 kPa

Valve closes at 1479 kPa

Noise level 50 dB(A)
NOx af 35 ppm
Safety devices Flame failure, boil-dry protection, overheat protection, fusible link, pressure relief valve and combustion fan rpm check
Water supply

Nominal operating pressure:

- 120-1000 kPa (A16)
- 160-1000 kPa (A20)
- 200-1000 kPa (A24 & A26)

Activation flow rate: 1.5 litres per minute


A16 = 13 kg, A20 = 14 kg, A24 and A26 = 15 kg


ES: Supplier Declaration of Compliance

Declaration numbers:

• A16 - 1825920179

• A20 - 1825820179
• A24 - 1825720179

• A26 - 1825620179

Market release 2018

Rinnai INFINITY A-Series connections and fittings diagram and table

Rinnai INFINITY A-Series dimensions diagram

Compare this...

Compare this

... to other great products

Enquire about a product

We’re happy to help with anything, big or small. Please fill out the short form below and we’ll get back to you within 24 hours.

Please enter your name Please enter your email address Please enter a subject Please enter a message

Where to Buy

Find a Rinnai reseller near you:

Or enter a postcode:

Brochures & Manuals