Rinnai INFINITY A-Series external gas continuous flow water heaters

Only on when you need hot water
RRP $1,852 *A16 $1,394, A20 $1,580, A24 $1,768

Rinnai INFINITY A-Series external 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.

Four 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 only
• mains and medium pressure systems

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

  • They are not suitable as a spa or swimming pool heater
  • They are not suitable for hydronic applications
  • They are not suitable as a gas boost for solar installations, or connection with an iHeat, as the temperature cannot be set high enough—use our HD models instead

Operating noise
Some people are susceptible to low level noise. INFINITY units operate at around 50-54 dB(A). This needs to be considered if locating the appliance near a bedroom.

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
Available fixed temperatures 40, 42, 50, 55, 60, 65 °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: 1.5-16 L/min
  • A20: 1.5-20 L/min
  • A24: 1.5-24 L/min
  • A26: 1.5-26 L/min
Input and output A16: Input: 16.3-124 MJ/h, output 27.8 kW
A20: Input: 19.9-156 MJ/h, output 34.9 kW
A24: Input: 16.3-184 MJ/h, output 42.0 kW
A26: Input: 16.3-199 MJ/h, output 44.5 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

Please note
If the inlet water pressure or flow rate drops below the minimum values stated above, operation of the INFINITY is not guaranteed. The unit requires both minimum flow rate and pressure to operate correctly.


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


Bathroom Deluxe Controller

Bathroom Deluxe Controller
Will run a bath for you, turn off the water, then tell you when it's ready. Adjust the water volume of the bath or shower, temperature and the volume of the voice.

Compact Controller (MC601A)

Compact Controller (MC601A)
Our smallest most affordable model. This controller can be installed anywhere in the house.

Kitchen Deluxe Controller

Kitchen Deluxe Controller
Designed for kitchens and laundries, works in conjunction with the Bathroom Deluxe Controller. The voice will tell you in the kitchen when your bath is ready.

Rinnai Flue Diverter - Sideways

Rinnai Flue Diverter - Sideways
An accessory that can be fitted to an external Rinnai continuous flow water heater. It is designed to expel combustion products in a sideways direction.

Rinnai Flue Diverter - Upwards

Rinnai Flue Diverter - Upwards
An accessory that can be fitted to an external Rinnai continuous flow water heater. It is designed to expel combustion products in an upwards direction.

Rinnai INFINITY® Pipe Cover

Rinnai INFINITY® Pipe Cover
A Rinnai pipe cover is available for a streamlined appearance, or to add additional protection in exposed installations.

Rinnai INFINITY® Security Bracket

Rinnai INFINITY® Security Bracket
A sturdy security bracket can be installed to act as a permanent deterrent against theft.

Rinnai Recess Box - Metal

Rinnai Recess Box - Metal
The metal recess box (white) enables an external continuous flow gas water heater to be recessed (either fully or semi-recessed) into an external wall, behind a door and out of sight.

Ducted Gas Heating Service Centre

Ducted Gas Heating Service Centre
Operating 5 days a week, 8am to 5pm, Monday to Friday our New Zealand based customer service centre provides nothing but top quality. If you need to book in a Ducted Gas Heating service, we have a team of providers fully trained and equipped with diagnostic tools to service your appliance when you need them. 

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