Dhwt - Domestic Hot Water Tank; Hydraulic Circuit - Hitachi RWM-(H)FSN3E Technical Catalogue

9 Piping work and
refrigerant charge

9.8 DHWT - Domestic Hot Water tank

9.8.1 Hydraulic circuit

When Piping connections are performed:
1 Connect all pipes as close as possible to the unit, so that disconnection can be easily performed when required.
2 It is recommended to use flexible joints for the piping of water inlet and outlet, so vibration will not be transmitted.
3 Whenever possible, sluice valves should be installed for water piping, in order to minimise flow resistance and to main-
tain sufficient water flow.
4 It is recommended to apply ball valves in both water pipe connections to make easier any maintenance work.
5 Proper inspection should be performed to check for leaking parts inside and outside the system, by completely opening
the hot water inlet and outlet valves to the water condenser.
6 This DHWT must be fully air purged to avoid heating elements radiating the tank case without water.
7 Apply thermal insulation on the hydraulic system pipes in order to avoid accidental injure due to excessive heat on
piping surfaces and also to avoid heat losses.
8 When the unit is stopped during shutdown periods and the ambient temperature is very low, it is possible that the water
in the pipes and in the circulating pump freeze, thus damaging the pipes and the water pump. In order to prevent this,
during shutdown periods it is useful to empty the water from the installation.
N O T E
Check periodically:
• Water flow and pressure
• Water leakage's
• Fixing points tightening
• Inlet and outlet connection pipes must be 1G"
126
TCGB0070 rev.3 - 04/2012
DHWT(200/300)(E/S)-2.5H1E
H.S.W.
Recirculation
Input
Return
Mains water
input
Ref. Name
 Sanitary safety valve unit
 Non-return valve
 Heating coil
 Recirculation pump
 Shutoff cock
 Drain
 Drain valve