The heat pump can produce domestic hot water at 57ºC as a maximum (53ºC for 2.0/2.5/3.0HP) by itself, but HITACHI recommends to set the
temperature of the tank by heat pump only up to 55ºC (50ºC for 2.0/2.5/3.0HP) and keep Thpoff default value. In case of higher setting, the tank's heater
must be used to reach the setting temperature (enabled by optional function).