Technical data

INSTALLATION
20
CIRCULATED HOT WATER FLOW AND RETURN SYSTEM
If a Rheem water heater is to be installed as part of a circulated hot water flow and return system, a storage
water heater able to provide a hot water outlet temperature of at least 60°C must be used. Note: The
thermostat must always be set to at least 60°C. Refer to the diagram on page 20.
Temperature Limiting Device
A temperature limiting device cannot be installed in circulated hot water flow and return pipe work unless it is
specifically designed to do so, such as the Rheem Guardian warm water system.
The tempered water from a temperature limiting device cannot be circulated. Where a circulated hot water
flow and return system is required in a building, a temperature limiting device can only be installed on a dead
leg, branching off the circulated hot water flow and return pipe.
If circulated tempered water were to be returned back to the water heater, depending on the location of the
return line connection on the water supply line to the water heater, then either:
water will be supplied to the cold water inlet of the temperature limiting device at a temperature
exceeding the maximum recommended water supply temperature, or
when the hot taps are closed no water will be supplied to the cold water inlet of the temperature limiting
device whilst hot water will continue to be supplied to the hot water inlet of the temperature limiting
device.
These conditions may result in either water at a temperature exceeding the requirements of AS/NZS 3500.4
being delivered to the hot water outlets in the ablution areas, or the device closing completely and not
delivering water at all, or the device failing. Under either condition, the operation and performance of the
device cannot be guaranteed.
LEGEND
Circulated Hot Water Flow and Return System – Gas Water Heater