Dhw Heater Function; High Demand Mode - Hitachi YUTAMPO Series Service Manual

3 Control functions

DHW Heater function

3.4 DHW Heater function
The DHW tank is fitted with a backup electrical heater. This electrical heater is disabled by factory settings and setting
cannot increase more than 55 ºC.
In case of setting higher than 55ºC or anti-legionella function, electrical heater must be enabled.
It is possible to define a waiting time for the activation of the electrical heater of the DHW tank. After this time, heater will
be switched ON in order to support Heat Pump to heat the tank.

3.4.1 High Demand Mode

19 SMGB0135 rev.0 - 06/2020
Status of electrical heater operation (enabled/
disabled)
Waiting time for the beginning of electrical heater
operation since compressor start-up (High speed
mode only)
In case of OFF, waiting time of Electrical heater
is not considered and heater will be switched ON
with Heat Pump
High Demand: DHW heating operation starts
if the differential is larger than differential
temperature. DHW can be heated up using the
heater, the heat pump or a combination of both.
Setting for domestic hot water temperature
selected by the user. The maximum value of this
setting depends on the Maximum Setting T set by
the installer. (Between 30 to Maximum Setting T.)
Maximum value of DHW setting temperature
permitted by the installer. (Between 40 ºC to 55ºC
or 75ºC when "Electric Heater" is enabled.)
Hysteresis of heater operation in High Demand
mode.
Hysteresis for the start of DHW heating operation
with the heat pump
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