Rheem 812 Series Owner's Manual And Installation Instructions page 51

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 an 874 series 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 must be of a type suitable for use with a continuous flow gas water heater and
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.
Two Temperature Zones Using a Temperature Limiting Device
An 876 series water heater will not deliver temperatures exceeding 50°C in accordance with AS 3498. There
is no need to fit a temperature limiting device to satisfy the requirements of AS/NZS 3500.4, if an 876 series
water heater is installed in an application where 50°C is the maximum permissible hot water temperature at
the outlet of a sanitary fixture used primarily for personal hygiene purposes. Refer to
Diagrams"
on page 55.
Gas Booster for a Solar Water Heater
The temperature limiting device used with an 874 series in-series gas booster as part of a solar water heater
installation must be of a type suitable for use with a solar water heater and have the capability of receiving a
hot water supply temperature of up to 99°C.
Warning: Temperature controllers must not be fitted to this water heater (874 series) 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 is installed to an existing water heater installation,
then all controllers must be disconnected and removed.
INSTALLATION – WATER HEATER
51
"Water Temperature