Mitsubishi Electric Ecodan HUS210FTC4ST Installation Manual page 55

Main Controller
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Hot Water And Heating Modes
Many options are available to suit the requirements of the end user, separate end user manuals and online
homeowner portals are available and it is part of the AEI terms and conditions that a thorough handover to the end
user is carried out. Hot water mode can be set to timed or auto reheat, the latter is more suitable for unpredictable
hot water usage patterns. When running the heating in timed mode setback periods can be entered throughout the
day, for example during unoccupied hours, for a heat pump system this is recommended as oppose to turning the
system off entirely. Setback temperatures in heating mode should not be less than 4ºC of the highest target
temperature.
Domestic Hot Water (DHW)/Legionella Prevention
The domestic hot water and legionella prevention menus control the operation of DHW tank heat ups. To set the
domestic hot water parameters first ensure the system is in installer mode so that the edit function appears.
1. Highlight the hot water icon and press CONFIRM.
2. Use button F1 to switch between Normal and ECO
heating modes.
3. To edit the mode press F2 to display the HOT WATER
(DHW) SETTING menu.
4. Use F2 and F3 keys to scroll through the menu
selecting each component in turn by pressing
CONFIRM. See the table below for description of
each setting.
5. Enter the desired number using the function keys
and press CONFIRM.
Explanation of DHW operation
• When the DHW tank temperature drops from "DHW max. temp" by more than the "DHW max.
temperature drop" (set by installer), DHW mode operates and the flow from the primary heating circuit
is diverted to heat the water in the DHW tank.
• When the temperature of the stored water reaches the 'DHW max. temp.' set by the installer or if the
'DHW max. operation time' set by the installer is exceeded DHW mode ceases to operate.
• Whilst DHW mode is in operation primary hot water is not directed to the space heating circuit.
• Directly after DHW max. operation time 'DHW mode restriction' will routinely operate. The duration of
this feature is set by the installer and during its operation DHW mode cannot (normally) be reactivated,
allowing time for the system to deliver primary hot water to the space heating if required. However, if at
this time there is no current demand for space heating, the system will automatically resume DHW
mode. This will continue until it receives a demand for space heating.
• After the 'DHW mode restriction' operation the DHW mode can operate again and DHW tank heating
will continue according to system demand.
DHW mode can run in either 'Normal' or 'Eco' mode. Normal mode will heat the water in the DHW tank more
quickly using the full power of the heat pump. Eco mode takes a little longer to heat the water in the DHW tank
but the energy used is reduced. This is because heat pump operation is restricted using signals from the
FTC4 based on measured DHW tank temperature.
(continued)
FTC4 Installation Manual
55