Specifications

INSTALLATION – WATER HEATER
17
MAINS WATER SUPPLY
Where the mains water supply pressure exceeds that shown in the table below, an approved pressure
limiting valve that does not have non return valve characteristics (such as an RMC PSL series valve) is
required and should be fitted as shown in the installation diagram (refer to page 24).
Model
27
Relief valve setting
1750 kPa
Max. mains supply pressure
1000 kPa
Min. mains supply pressure *
140 kPa
* minimum water supply pressure required to achieve the
rated flow and performance
Notes:
It is not recommended to install this water heater with a low pressure water supply.
A minimum water supply pressure of 140 kPa is required to achieve the rated flow and performance of
the water heater.
If this water heater is installed as an in-series gas booster for a solar water heater, the maximum water
supply pressure to the solar water heater, without an expansion control valve (ECV), is generally
800 kPa, however it may be less than this for some models. Refer to the Owner‟s Guide and Installation
Instructions supplied with the solar water heater for maximum mains supply pressure details.
If sludge or foreign matter is present in the water supply, it is recommended a suitable filter be
incorporated in the cold water line to the water heater.
This water heater is not suitable for connection to bore water or spring water unless a water treatment
device is fitted.
Refer to “Water Supplies” on page 11 for further information on water chemistry.
PRESET OUTLET TEMPERATURE SETTING
The factory preset outlet temperature setting of the water heater is:
862 series 60°C for a single water heater
60°C as part of a Multipak system
70°C as part of a Commpak system
It is usually not necessary to check or adjust the factory preset outlet temperature setting of the water heater,
unless the customer or application has a particular requirement for this to be done.
For applications requiring sanitising temperatures, such as a commercial kitchen, it will be necessary to
adjust the preset outlet temperature setting to 82°C.
If the water heater is installed as part of a circulated hot water flow and return system in a building, the preset
outlet temperature setting must be set to at least 60°C. If the water temperature decreases by more than 5°C
through a circulated hot water flow and return system due to heat loss in the ring main, the preset outlet
temperature setting of the water heater should be set to at least 65°C.
Gas Booster for a Solar Water Heater
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 or
higher, and that a remote temperature controller is not used.
It will be necessary to check and if required to adjust the preset outlet temperature setting of the continuous
flow water heater when:
it is installed as an in-series gas booster to a solar water heater
it is an existing continuous flow water heater and a solar water heater is then installed.
Refer to “Preset Outlet Temperature Setting” on page 51.