Demand Duo Lite


Range Discontinued
Discontinued 2012, developed for high demand residential, and light commercial applications

The Demand Duo Lite is comprised of an electric tank and gas boost continuous flow water heater. Ideal for applications requiring a large, intermittent demand for hot water. For example, spa baths, large homes with multiple showers being used simultaneously, small hair salons or small launderettes. External installations only.

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Product Details

Benefits at a glance
The high input, fast heating system ensures the storage tank refills and reheats fast.

Heavy duty insulation minimises heat loss to keep energy costs under control.

Status monitor makes it easy to check on the operation of your water heater.

System is centralised which helps to reduce the total cost of installation.

How it works
The thermostat senses the temperature of the water in the tank, and when it drops below the set temperature, the primary pump is activated. This in turn starts the Rinnai continuous flow water heater which returns heater water to the tank. 

Technical Specifications

Storage capacity

180 L or 240 L

Input and thermal efficiency of INFINITY unit

160 MJ/h or 44 kW


Gas supply, cold water inlet, and hot water outlet—all 20 mm

Delivery based on incoming water temp. of 15, 10, and 5 °C
  • 180 L, first hour at 40 °C = 1019 L, 947 L, 837 L
  • 180 L, first hour at 55 °C = 719 L, 652 L, 545 L
  • 340 L, first hour at 40 °C = 1411 L, 1247 L, 1117 L
  • 340 L, first hour at 55 °C = 952 L, 870 L, 978 L

Grundfos UPS 20-60 B 150

Recovery at 50 °C rise

180 L, approx. 36 minutes
240 L, approx. 67 mins

Tank construction

Glass lined inner, corrosion resistant outer and high density expanded polyurethane foam insulation


Preset to 65 ºC

TPR setting

180 L - 1000 kPa
340 L - 850 kPa

  • 180 L empty - 100 kg, full - 280 kg
  • 340 L empty - 142 kg, full - 482 kg