Mitsubishi Electric EHST20C-VM6HA Service Manual page 33

<Heat source setting>
The default heat source setting is heat pump and all electric heaters present in
the system to be operational. This is referred to as Standard operation on the
menu.
From the service menu use F1 and F2 buttons to scroll through list until
1.
is highlighted.
. Press CONFIRM.
Heat source setting menu screen is displayed.
3.
4. Press F3 button until preferred heat source is displayed.
5. Press CONFIRM.
6. To return to service menu press MENU or BACK button.
If you wish to return to the service menu without saving the setting press re-
7.
turn button. You will be asked if you are sure you wish to cancel the changes.
Choose Yes or No as appropriate.
Operation Setting Menu
To access the Operation setting menu use F1 and F2 buttons to scroll through
1.
the service menu until Operation setting is highlighted.
. Press CONFIRM.
Operation setting menu is displayed.
3.
<Simultaneous Operation>
For periods of very low outside temperature this mode can be used. Simultane-
ous operation allows both DHW and space heating to be provided simultaneously
by using the heat pump to provide space heating whilst only the immersion heater
(if fitted) provides heating for DHW. This operation is only available if BOTH a
DHW tank AND immersion heater are present on the system.
From the Operation setting menu use F1 and F2 buttons to scroll through the
1.
list until Simultaneous operation is highlighted.
. Press CONFIRM.
3. Simultaneous operation screen is displayed.
To switch simultaneous operation ON/OFF press F1.
4.
To alter the temperature at which simultaneous operation starts use F3 and F4.
5.
Note: Range of ambient (outdoor) temperature is -15°C to 10°C (default -15°C).
To return to Operation setting menu press BACK.
6.
<Cold weather function>
For extremely low outdoor temperature conditions when the heat pump's ca-
pacity is severely restricted the heating or DHW is provided by only the electric
booster heater (and immersion if present). This function is intended for use during
extreme cold periods only. Extensive use of direct electrical heaters ONLY will
result in higher electric usage and may reduce working life of heaters and related
parts.
From the Operation setting menu use F1 and F2 buttons to scroll through the
1.
list until Cold weather function is highlighted.
. Press CONFIRM.
Cold weather function screen is displayed.
3.
To switch Cold weather function ON/OFF press F1.
4.
To alter the temperature at which heater switching function starts use F3 and F4.
5.
Note: Range of ambient (outdoor) temperature is -15°C to -10°C (default -15°C)
To return to Operation setting menu press BACK.
6.
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Heat source setting screen
Cancel last action screen
Operation setting menu screen
Simultaneous operation screen
Cold weather function screen