External Input Settings; Floor Dry Up Function; Demand Control (In4); Outdoor Thermostat (In5) - Mitsubishi Electric EHST20C-VM6HB Service Manual

<Floor dry up function>
The Floor dry up function automatically changes the target hot water temperature
in stages to gradually dry concrete when this particular type of underfloor heating
system is installed.
1. Turn off the system using the main controller.
2. From the Operation settings in the service menu, use F1 and F2 buttons to
scroll through the list until Floor dry up function is highlighted.
3. Press CONFIRM to display the FLOOR DRY UP screen.
4. To change settings, press F4. For details on settings, refer to the table below.
5. To start the Floor dry up operation, press F1 button to check a box below
"Active" and press CONFIRM.
*1. Upon completion of the operation the system stops all the operations except
the Freeze stat. operation.
*2. For Floor dry up function, the target flow temp. of Zone1 is the same as that of
Zone.
Note:
• This function is not available when a PUHZ-FRP outdoor unit is connect-
ed.
• Disconnect wiring to external inputs of room thermostat, demand control,
and outdoor thermostat, or the target flow temp. may not be maintained.
Functions

Floor dry up function

Flow temp. increase step
Flow temp.
(increase)
Increase interval
Flow temp. decrease step
Flow temp.
(decrease)
Decrease interval
Start & Finish
Target temperature Max. target temp.
Max. temp. period

External input settings

From the service menu use F1 and F2 buttons to highlight External input settings
then press CONFIRM.
<Demand control (IN4)>
From the External input settings menu highlight Demand control (IN4).
1.
Press CONFIRM.
.
. The Demand control screen is displayed.
Press F3 button to select Heat source OFF or Boiler.
4.
Press CONFIRM.
5.
Note: The selection of "OFF", whilst a signal is being sent to IN4, forcefully
stops all the heat source operations and the selection of "Boiler" stops
operations of heat pump and electric heater and performs boiler op-
eration.
<Outdoor thermostat (IN5)>
From the External input settings menu highlight Outdoor thermostat (IN5).
1.
Press CONFIRM.
.
. The Outdoor thermostat screen is displayed.
Press F3 button to select Heater or Boiler.
4.
Press CONFIRM.
5.
Note: The selection of "Heater", whilst a signal is being sent to IN5, performs
electric-heater-only operation and the selection of "Boiler" performs
boiler operation.
OCH531
Symbol Description
Set the function to ON and power on the system using the main
a
controller, and the dry up heating operation will start.
Sets the increase step of the target flow temp.
b
Sets the period for which the same target flow temp is maintained.
c
Sets the decrease step of the target flow temp.
d
Sets the period for which the same target flow temp is maintained.
e
Sets the target flow temp. at the start and the finish of the operation.
f
g Sets the maximum target flow temp.
Sets the period for which the maximum target flow temp. is maintained. 1 - 0
h
41
Target flow temp.
(°C )
(h)
45
(g)
40
35
(b)
(c)
30
(f)
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Days
Option/Range Unit
On/Off
+1 - +10
−1 - −7
−1 - −10
1 - 7
5 - 60
5 - 60
External input settings menu screen
Demand control screen
Outdoor thermostat setting screen
(d)
(e)
Default
— Off
ºC
+5
day 
ºC −5
day 
ºC
0
ºC
45
day 5