INSTALLATION
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WATER HEATER
29
HOT WATER DELIVERY
This water heater can deliver water at temperatures which can cause scalding.
It is necessary and we recommend that a temperature limiting device be fitted between a CF20-60 model
water heater and the hot water outlets in any ablution and public areas such as a bathroom, ensuite or public
amenities, to reduce the risk of scalding. The installing plumber may have a legal obligation to ensure the
installation of this water heater meets the delivery water temperature requirements of AS/NZS 3500.4 so that
scalding water temperatures are not delivered to a bathroom, ensuite or other ablution or public area.
The temperature limiting device used with a continuous flow gas water heater should have:
a specified „minimum temperature differential‟ between the hot water inlet and the tempered water outlet
of no greater than 10°C, and
a specified „maximum permitted pressure variation‟ in the supply between the hot water inlet and the
cold water inlet of no less than 15%.
Refer to the specifications of the temperature limiting device.
Where a temperature limiting device is installed adjacent to the water heater, the cold water line to the
temperature limiting device can be branched off the cold water line either before or after the isolation valve
and pressure limiting valve to the water heater.
If a pressure limiting valve is installed on the cold water line to the water heater and the cold water line to a
temperature limiting device branches off before this valve or from another cold water line in the premises,
then a pressure limiting valve of an equal pressure setting may be required prior to the temperature limiting
device.
LEGEND
Two Temperature Zones Using a Temperature Limiting Device
A CF20-50 model water heater will not deliver temperatures exceeding 50°C in accordance with AS 3498.
There is no statutory 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.
Refer to
on page 33.
