ABOUT YOUR WATER HEATER
WATER HEATER APPLICATION
This water heater is designed for the purpose of heating potable water. Its use in an application other than
this may shorten its life.
The Rheem® continuous flow gas water heater model you have chosen is for outdoor installation only. This
model has an extended manufacturer’s warranty (refer to the Rheem warranty on page 39).
The water heater has a maximum preset outlet temperature setting of:
872 series 82°C
If a temperature controller is connected to the water heater, this will
override the preset outlet temperature setting and the maximum
temperature setting will be:
Kitchen controller connected 60°C
Bathroom controller only connected 50°C
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. 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 872 series water heater may be installed as an in-series gas booster to a solar water heater. 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.
Water stored in the solar storage tank passes through the in-series gas booster when a hot tap is opened.
Solar heated water can reach temperatures up to 70°C to 80°C for a Premier Loline and Loline pumped
system and a Hiline thermosiphon system and possibly higher for a Premier Hiline thermosiphon system.
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 is at a temperature higher than 2°C below a water heater preset outlet
temperature setting of up to 75°C (i.e. 68°C or above if the preset outlet temperature setting is 70°C) or
higher than 4°C below a water heater preset outlet temperature setting of 82°C, the flow passes through the
in-series gas booster without boosting. When the solar heated water is at a temperature lower than 2°C
below a water heater preset outlet temperature setting of up to 75°C (i.e. below 68°C if the preset outlet
temperature setting is 70°C) or lower than 4°C below a water heater preset outlet temperature setting of
82°C, the in-series gas booster heats the water to a minimum temperature of the preset outlet temperature