INSTALLATION
27
CIRCULATED HOT WATER FLOW AND RETURN SYSTEM
An E5X series water heater cannot be installed as part of a circulated hot water flow and return system in a
building.
An E6X series water heater should not be installed as part of a circulated hot water flow and return system in
a building. The benefits of the controlled electricity supply or PV generated power supply will be significantly
reduced.
If a circulated flow and return system is required, it is necessary to install a secondary water heater supplied
from the E6X series water heater. The flow and return lines connect to the secondary water heater, not this
water heater. The secondary water heater makes up for the pipe heat loss in the flow and return system and
must be able to provide a hot water outlet temperature of at least 60°C.
Note:
The thermostat temperature of the secondary water heater must always be set to maintain a temperature
of at least 60°C in the hot water flow and return line, including making up pipe heat losses in the system.
Refer to the
Circulated Hot Water Flow and Return
– Grid Interactive or PV Powered Electric Water Heater
diagram on page 27.
Temperature Limiting Device
A temperature limiting device cannot be installed in circulated hot water flow and return pipe work. 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 secondary 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.
This condition 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 this condition, the operation and performance of the device cannot be
guaranteed.
Circulated Hot Water Flow and Return System
Grid Interactive or PV Powered Electric Water Heater
