Mains pressure, How hot should the water be, Hotter water increases the risk of scald injury – AquaMAX CG20 Series User Manual
Page 5

ABOUT YOUR WATER HEATER
5
MAINS PRESSURE 
The water heater is designed for direct connection to the mains water supply. If the mains supply pressure in 
your area exceeds that 
28, a pressure limiting valve must be fitted. The supply pressure
should be greater than 140 kPa for the rated flow and performance to be achieved. 
 
HOW HOT SHOULD THE WATER BE? 
The water heater may be installed with one or more user 
adjustable temperature controllers, which allow you to 
choose the most suitable temperature for your hot water 
needs (refer to 
on page 11).
 
If a controller is not installed, the water heater heats the 
water to the preset outlet temperature setting. The factory 
preset outlet temperature setting is: 
CG20-60 series
60°C
CG20-50 series
48°C
 
Note:
The preset outlet temperature setting of this water
heater cannot be adjusted by the householder. The setting 
can only be adjusted by the installer or Aquamax Service. 
 
Note: AS 3498 requires that a water heater provides the 
means to inhibit the growth of Legionella bacteria in potable 
water. When this water heater is used as an in-series booster 
for a solar water heater it can satisfy this AS 3498 
requirement provided it is energised, the booster preset outlet 
temperature setting is 70°C, and that a remote temperature 
controller is not used. 
 
Warning: Temperature controllers must not be fitted to this water heater (CG20-60 model) if it is
installed as an in-series gas booster with a solar water heater system because water at a temperature much 
higher than the controller setting can be delivered. If a solar water heater has been installed to an existing 
water heater installation, then all controllers must be disconnected and removed. 
 
If this water heater is installed as part of a solar water heater system, the system can deliver water at 
temperatures from 58°C up to 80°C with an Aquamax pumped direct solar water heater. 
 
HOTTER WATER INCREASES THE RISK OF SCALD INJURY 
This water heater can deliver water at temperatures which can cause scalding. Check the water temperature 
before use, such as when entering a shower or filling a bath or basin, to ensure it is suitable for the 
application and will not cause scald injury. 
 
We recommend and it may be required by regulations that an approved temperature limiting device be fitted 
into the hot water piping to the bathroom and ensuite when a CG20-60 model water heater is installed. This 
will keep the water temperature below 50°C at the bathroom and ensuite. The risk of scald injury will be 
reduced and if no controllers are installed or if a Kitchen controller is installed, still allow hotter water to the 
kitchen and laundry. 
 
A CG20-50 model water heater will not deliver temperatures exceeding 50°C, in accordance with AS 3498. 
There is no requirement in AS/NZS 3500.4 to fit a temperature limiting device if this water heater is installed 
in other than an early childhood centre, school, nursing home or a facility for young, aged, sick or disabled 
people. 
 
maximum Kitchen controller
temperature setting
CG20-60 series
maximum recommended supply
temperature to bathrooms and
ensuites.
maximum Bathroom controller
temperature setting
CG20-60 series
maximum Kitchen and Bathroom
controller temperature setting
CG20-50 series
minimum Kitchen and Bathroom
controller temperature setting
