STIEBEL ELTRON FEK User manual

26_03_01_0106
270783
26_03_01_0106
FEK
Control module
Operating and installation instructions

2
Index
1. Operating instructions 2
for users and contractors
1.1 Equipment description 2
1.2 Equipment overview 2
1.3 Important information 2
1.4 Operation 3
1.5 Settings 3
2. Installation instructions 12
for contractors
2.1 Standard delivery 12
2.2 General 12
2.3 Installation 12
2.4 Specification 13
2.5 Commissioning 13

3
1 Operating instructions for users and contractors
1.2 Equipment overview
1.2.1 With closed control flap and standard
display
1.1 Equipment description
The FEK control module only works in
conjunction with the weather-compensated
WPMi control unit. It enables the convenient
entry and display of system parameters, e.g.
outside temperature, relative humidity and
heating circuit parameters (e.g. heating times
and required room temperature) for the
heating system from the user’s living room.
This allows the constant monitoring and
optimising of the heating system, both in
heating and in cooling mode.
In addition, hooking up a room temperature
enables the correction of the weather-
compensated WPMi control unit.
1.3 Important information
The control module must only be
installed and maintained by qualified
contractors.
1.4 Operation
The operation is split over three control levels.
Control levels 1 and 2 are accessible to users
and contractors alike. Control level 3 is only
designed for qualified contractors:
Control level 1 (control flap closed)
This enables the adjustment of operating
modes, such as standby mode, programmed
operation, constant day or setback mode (for
this, see section 1.5.1).
Control level 2 (control flap open)
This enables parameters, such as room
temperature, heating programs, etc. to be
adjusted (for this, see section 1.5.5).
Time
Room temperature
Day
Heating times
Relative humidity
1 Away key
2 Operating mode key
3 Help key
4 Rotary selector for changing the set
room temperature ± 5 K
1 2 3 4
1.2.2 With the control flap open and with all
indicator elements on display
123 4 5
1 Programming indicator
2 + key
3 PRG key
4 - key
5 Reset
C26_21_01_0010
C26_21_01_0011

4
Vital facts in brief
Settings
All adjustments follow the same pattern:
Opening the control flap toggles the FEK
to control level 2. The display shows the
parameter “room temp.”.
Pressing enables you to adjust the
parameter you want to change.
Press to change the value of the
parameter. You can change the currently
displayed value with or , when the red
indicator is illuminated. Press again, the
indicator then extinguishes and the new
set value has been saved. You can modify
further values for this parameter by pressing
or , if the red indicator has not been
extinguished after saving.
The programming step can only be
terminated when the red indicator has
extinguished.
Terminating programming
You can terminate the programming process
after entering and saving the required
parameter changes by closing the control
flap. However, if you want to make further
changes, press one of the keys until the
display shows BACK, then press . This
will return you to the previous level. Closing
the control flap with illuminated indicator
returns the FEK into its original position. The
modified value will then not be saved.
1.5 Adjustments (control level 1)
With the flap closed, the display shows the
operating mode, time and day, as well as
the current room temperature and relative
humidity.
1.5.1 Operating mode key
When connecting a FEK, only the operating
modes for the pre-selected heating circuit are
adopted by the WPMi.
You can select the required operating mode
by pressing this key several times with the
flap closed. The selected operating mode is
indicated by a symbol in the display. It becomes
effective if the setting was not changed for five
seconds.
Standby mode
Frost protection for the heating operation
is active. The standby symbol flashes, when
the heat pump manager is in standby
mode, and the operating mode cannot be
adjusted.
Application: During holidays.
Automatic mode
Heating according to time switch program.
Changeover between day temperature
and setback temperature. With this
operating mode, an additional symbol (sun
or moon) indicates in the display, whether
the heating circuit is currently in day or in
setback mode.
Constant day mode
The heating circuit is held at constant day
temperature.
Application: In low energy houses without
setback mode.
Constant setback mode
The heating circuit is held at constant
setback temperature.
Application: During weekends away.
Control level 3 (for contractors only)
This level is protected by a code and should
only be used by contractors. At this level,
heat pump and system-specific details are
determined (for this, see section 2.5).

5
1.5.2 Away key
This key activates the eco mode (away).
Press twice: The heating circuit switches to
setback mode for one hour. The selected
heating interruption is briefly displayed in
hours.
Press this key several times: the heating circuit
switches for the respective number of hours
to setback mode. If no key is then pressed for
approx. three seconds, the display returns to
the standard display and the active heating
interruption is displayed by the flashing moon
symbol.
You can scan the selected heating interruption
by pressing the “Away” key once at any time.
Pressing the operating mode key deactivates
the “Away” period and the moon symbol will
extinguish.
1.5.3 Help key
Pressing this key allows you to scan sensor
temperatures of the heat pump or heat
pump system, such as outside temperature,
actual DHW temperature, actual return
temperature, actual room temperature and
the relative humidity.
Display (including all elements)
1 Heating times for central
heating and DHW (black)
2 12-digit plain text display
3 Mixer mode
4 Heating mode
5 DHW mode
6 Cooling mode
7 Compressor runs
8 Booster in operation
Stage 1, 2 or 3
9 Fault message (flashing)
10 ‘BUS connection to the
WPMi established
11 WPMI in away mode
12 Standby mode
13 Automatic mode
14 Constant day mode
15 Constant setback mode
16 Day
After you press this key, the first display is
the outside temperature. Continuing to
press displays, in sequence, the actual DHW
temperature, the actual return temperature,
the maximum and minimum room
temperatures and the maximum and minimum
relative humidity. The standard display returns
after five seconds.
The MIN/MAX values for room temperature
and relative humidity are constantly updated
and stored.
If you hold down the key for four seconds, the
top of the display shows DELETE VALUES. All
MIN/MAX values will then be deleted.
Any fault in the heat pump causes an arrow
above the help key and the attention symbol
to flash. Pressing the help key displays that
fault. Three seconds later, the fault display
extinguishes and the standard display returns
again.
1.5.4 Room temperature
You can adjust the room temperature by
+/- 5K with the rotary selector. This set value
adjustment applies to the then current heating
time, not to the setback time.
1 2 3 4567 8
12 13 14
9
15 16
10 11
C26_21_01_0012

6
With the Room temp. parameter you can adjust the set
room temperature of the heating circuit for the day and
setback mode.
In the Heating curve parameter, you can adjust the
heating curve. The room temperature will only remain
constant, irrespective of the outside temperature, if the
correct heating curve has been selected for the relevant
type of building. Selecting the correct heating curve is
therefore vitally important.
In the Heating program parameter, you can adjust the
heating program.
The Temperatures parameter enables you to scan the
sensor temperatures of the heat pump or heat pump
system, comparing the actual with the set temperatures,
the relative humidity, etc..
During commissioning, you need to not only determine
the settings of control level 2, but also the system-specific
parameters. These parameters are adjusted at control
level 3 by your heating contractor, access to which is
protected by code.
1.5.5 Overview of system parameter (control level 2)
Select the required parameter with the rotary selector.
For adjustments to parameters, turn to page 6.
ROOM T
HTG PROG
TEMPERATURES
HTG CURVE
CONTRACTOR

7
Temperatures
The Temperatures parameter enables you to
scan the following sensor temperatures of the
heat pump or heat pump system, comparing
the actual with the set temperatures, the
relative humidity, etc..
– Outside temperature
– Actual room temperature
– Set room temperature
– Relative humidity
– Actual DHW temperature
– Set DHW temperature
– Actual heat pump return temperature
– System frost protection temperature
Note
No display, if the corresponding temperature
sensor is not connected.
Room temperature
With the Room temp. parameters you can
adjust the set room temperature for the day
and setback mode. Changing these parameters
results in a parallel offset of the heating curve.
The heating curve, room temperature
and heating program parameters are
not shown at the WPMi heat pump manager,
if the FEK is pre-selected for a specific
heating circuit.
Adjustments at control level 2 for users and contractors
Open the control flap
ROOM T
SET DAY
SET DAY
SET DAY
SET HIGHT
SET HIGHT
SET HIGHT
ROOM T
BACK

8
Open the control flap
Heating program
Under this parameter you have the option of
setting up a heating program, i.e:
– for every day of the week (Mo, ..., Su)
– Monday to Friday (Mo - Fr)
– Saturday and Sunday (Sa - Su)
– the whole week (Mo - Su)
You can adjust three switching time pairs (I, II,
III) for each of these options.This determines
when and how often the heat pump system
should heat in day mode.
Open the control flap
At all other times, the heat pump operates
in setback mode. You will already have
selected the corresponding set values for day
and setback mode under the Room temp.
parameter.
Example:
Your heating system should operate daily
from Monday to Friday at two different times,
i.e. from 05:30 h until 08:30 h and from 14:00
h until 22:00 h. For the weekend, your heating
system should provide heat from 08:30 h until
21:00 h.
OUTDOOR TEMP
BACK
TEMPERATURES
TEMPERATURES
HTG PROG
MON-FRI
ON
ON
OFF

9
Heating curve
The Heating curve parameter allows you to
select a heating curve for heating circuit 1 or
2. Selecting the correct heating curve is vitally
important.
Note: Your contractor will have set up a
building and system-specific optimum heating
curve for the heating circuit. It relates to the
heat pump return temperature for heating
circuit 1 and to the mixer flow temperature for
heating circuit 2.
When adjusting the heating curve, the
calculated set return or flow temperature,
which is subject to the outside temperature
and the set room temperature, will be shown
at the top of the display.
26_21_01_0013
Relative to +20 °C
Outside temperature
Relative to 0 °C
Outside temperature
Relative to -20 °C
Outside temperature
Relative to +20 °C
Outside temperature
Relative to 0 °C
Outside temperature
Relative to -20 °C
Outside temperature
BACK
ON
OFF
ON
ON
ON
OFF
SAT - SUN

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Open the control flap
26_03_01_0077
1,5
2
1,2
1
0,6
0,4
0,2
2,5
3
20 18 16 14 12 10
8 6 4 2 0
-2 -4 -6 -8
-10 -12 -14 -16 -18 -20
100
80
60
40
20
Außentemperatur [°C]
Heizkreis 2 WP-Vorlauftemperatur [°C] Heizkreis 1 WP-Rücklauftemperatur [°C]
0,8
Heating curve diagram
One heating curve respectively can be adjusted for heating circuit 1 and heating circuit 2.
At the factory, heating curve 0.6 is set up for heating circuit 1 and heating curve 0.2 for
heating circuit 2. These heating curves relate to a set room temperature of 20 °C.
Heating circuit 1, HP return temperature [°C] Heating circuit 2, HP flow temperature [°C]
Outside temperature [°C]
HTG CURVE
BACK