Rinnai INFINITY® HD200 external & HDi200 internal


Heavy duty on demand for demanding jobs

**Superseded by the HD49 series in 2022**

Rinnai INFINITY HD units are higher capacity gas continuous flow water heaters for applications where higher flow rates and higher temperatures are needed. 

The HD200 external has an inbuilt status monitor, which has an added feature of displaying an LC (00) error code when the unit requires cleaning (due to scale build-up).

Two models to choose from:

  • HD200 external unit with status monitor
  • HDi200 internal unit

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Product Details

Suitable for

  • HD200 is for external commercial and residential applications.
  • HDi200 is for internal commercial and residential applications.

Mains and medium pressure systems. Hard or acidic water will need to be treated to use this product.

Not suitable
- as a spa or swimming pool heater
- for hydronic applications

Technical Specifications



Preset temp.

55 & 75 °C




21 kg

HD200 preset temp is 75 °C
Gas type

Available for Natural Gas or LPG, specify at the time of purchase

Codes and REU numbers
Model Code NG Code LPG REU number
Hot water capacity
  • HD200, 2.4-30 L/min, nominal water capacity is 26 L/min at a 25 °C rise (1560 L/h)
  • HDi200, 2.4-32 L/min, nominal water capacity is 26 L/min at a 25 °C rise (1560 L/h)
Input and output
Model Input Output kW
HD200 199 MJ/h or 55 kW 45.9 kW
HDi200 195 MJ/h or 54 kW 44.5 kW
Hot water connections
  • Hot water outlet R¾ (20 mm)
  • Cold water inlet R¾ (20 mm)
  • Gas supply R¾ (20 mm) 
Ignition system

Direct electronic ignition

Exhaust system
  • External unit - forced flue
  • Internal unit - room sealed 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.

Injector sizes
Model NG LPG
HD200 1.25, 1.95 0.75, 1.15
HDi200 1.00, 1.70 0.75, 1.15
Ingress protection rating


Line pressure (min.)

NG - 1.13kPa, 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.

Noise level

59 dB(A). Some people are susceptible to low level noise. This needs to be considered if locating an appliance near a bedroom.

NOx af

less than 60 ppm

Power consumption
  • HD200, normal 48 W (NG), 60 W (LPG), automatic frost protection 100 W
  • HDi200, normal 64 W (NG), 67 W (LPG), automatic frost protection 100 W

Both units have a standby of 2 W

Pressure relief

Valve opens at 2060 kPa, closes at 1470 kPa

Safety devices
  • Flame failure
  • Boil-dry protection
  • Overheat protection
  • Fusible link
  • Pressure relief valve
  • Combustion fan RPM check
Water supply

Nominal operating pressure: 

  • HD200: 130-1000 kPa
  • HDi200: 140-1000 kPa

Activation flow rate: 2.4 litres per minute

Please note: If the water inlet 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.


Energy Safety Supplier Declaration of Compliance declaration numbers:

  • HD200 - 12410201012
  • HDi200 - 10978200911
Market release
  • HD200, first launched 2010 and then relaunched in 2011
  • HDi200 - 2011
Last sold

HDi200 - Nov 2021 (superseded by HD49kWi)
HD200 - Mar 2022 (superseded by HD49kWe)