About Your Water Heater - Rheem 812 Series Owner's Manual And Installation Instructions

WATER HEATER APPLICATION
This water heater is designed for use in a single family domestic dwelling for the purpose of heating potable
water. Its use in an application other than this may shorten its life.
MODEL TYPE
®
The Rheem continuous flow gas water heater model you have chosen is
for outdoor installation only.
The water heater has a maximum preset outlet temperature setting of:

874 series

876 series
Note: The 876 series water heater is marked "THIS APPLIANCE DELIVERS
WATER NOT EXCEEDING 50°C IN ACCORDANCE WITH AS 3498" on the
front panel.

An 876 series model must not be installed as an in-series gas booster
to a solar water heater, as water temperature greater than 50°C can be
delivered from the water heater contravening its compliance to AS 3498.
WATER HEATER OPERATION
The water heater operates automatically, heating water as it passes through the water heater. When a hot tap
is opened, the gas burners ignite to provide immediate heating of the water. The heat produced by the burner
is transferred to the water through the heat exchanger. The water is heated to a constant temperature by the
automatic adjustment of the gas supply to the burner to suit the water flow rate (refer to
on pages 13 to 42). The gas burners extinguish when the hot tap is closed.
Automatic safety controls are fitted to the water heater to provide safe and efficient operation.
REDUCED HOT WATER FLOW WHEN HEAT EXCHANGER IS COLD
At a cold start-up, i.e. when the water heater has not operated for some time (which is most often first thing in
the morning), the initial flow of hot water may be reduced for a period of 5-10 seconds while the heat exchanger
warms up. This is both an energy and water saving feature of this water heater. Once the heat exchanger
has warmed up the hot water flow will increase and remain at normal flow levels. This feature will only occur
at a cold start-up and not when the heat exchanger is already warm from a recent use of hot water.
GAS BOOSTING FOR A SOLAR WATER HEATER
The 874 series water heater may be installed as an in-series gas booster to a solar water heater.
Water stored in the solar storage tank passes through the in-series gas booster when a hot tap is opened. The
in-series gas booster is for heating water at times of low solar energy gain, such as during cloudy or rainy
weather, or during colder months.
The in-series gas booster operates automatically. When the solar heated water temperature is below 58°C,
the in-series gas booster heats the water to its preset outlet temperature setting.
Solar heated water can reach temperatures up to 70°C to 80°C for a Premier Loline and Loline pumped system
and possibly higher for a Hiline and Premier Hiline thermosiphon system. When the solar heated water
temperature is 58°C or higher, the flow passes through the in-series gas booster without boosting.
For information relating to the function and operation of the solar water heater, refer to the Owner's Guide and
Installation Instructions supplied with the solar water heater.

ABOUT YOUR WATER HEATER

75°C
50°C
6
"Temperature Control"