Hitachi YUTAKI RWM-2R1E Installation & Operation Manual page 356

MAINTENANCE
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Draining
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N O T E
Draining operation is unique for each model. Refer to the service manual of the specific unit for drain operation procedure.
Draining operation for YUTAKI S
YUTAKI S models have no drain port factory supplied. It must be considered the installation of a drain port after the shut-off valve
(factory supplied) and before the water inlet of the unit when proceeding to the installation of the unit.
Draining operation for YUTAKI S COMBI
Draining of the indoor unit
1 Switch OFF the main power supply of the indoor unit.
2 Close the 2 shut-off valves (factory-supplied) installed at the space
heating connections (Water inlet and outlet connections).
3 Open manually the drain port for indoor unit water and collect the
water into a bucket.
4 Once all the water has been drained, close again the drain port for
indoor unit water.
!
C A U T I O N
When draining the indoor unit water from its drain port, the leaved water could
be hot and could keep in pressure. Perform the draining procedure carefully.
Draining of the DHW circuit
1 Switch OFF the main power supply of the indoor unit.
2 Close the main DHW inlet valve (water inlet shut-off valve) in order
to avoid the tank filling.
3 Open the shut-off valve of the DHW outlet to allow draining without
creating a vacuum. Ensure that valve at the highest level of the
DHW system is also opened.
4 Connect a drain hose to the drain port for DHW and lead the other
end to the general draining.
5 Open manually the drain port for DHW and wait a long time until
all the water has been removed.
!
C A U T I O N
When draining the DHW from its drain port, the leaved water could be hot and
could keep in pressure. Perform the draining procedure carefully.
342 PMML0575 rev.2 - 03/2022
RWD-(2.0-3.0)RW1E-220S(-K)
RWD-(4.0-6.0)NW1E-220S(-K)
Indoor unit
Drain
DHWT Drain
Indoor unit
Drain
DHWT Drain