STIEBEL ELTRON wpf 20 Instruction Manual

OPERATION AND INSTALLATION
Brine-water heat pumps
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2| WPF 20-66 www.stiebel-eltron.com
CONTENTS
SPECIAL INFORMATION
OPERATION
1. General information �����������������������������������������3
1.1 Relevant documents_____________________________________________ 3
1.2 Safety instructions_______________________________________________ 3
1.3 Other symbols in this documentation _______________________ 4
1.4 Units of measurement __________________________________________ 4
1.5 Standardised output data ______________________________________ 4
2. Safety����������������������������������������������������������4
2.1 Correct use________________________________________________________ 4
2.2 Safety instructions_______________________________________________ 4
2.3 Test symbols ______________________________________________________ 4
3. Device description �������������������������������������������5
3.1 Operational characteristics ____________________________________ 5
3.2 Function ___________________________________________________________ 5
4. Control ��������������������������������������������������������5
5. Maintenance and care ���������������������������������������5
6. Troubleshooting ����������������������������������������������5
INSTALLATION
7. Safety����������������������������������������������������������6
7.1 General safety instructions ____________________________________ 6
7.2 Instructions. standards and regulations ____________________ 6
8. Device description �������������������������������������������6
8.1 WPF 20 | 27________________________________________________________ 6
8.2 WPF 35 | 40 | 52 | 66 _____________________________________________ 6
8.3 WPF 27 HT_________________________________________________________ 6
9. Standard delivery ��������������������������������������������7
9.1 Accessories________________________________________________________ 7
10. Installation����������������������������������������������������7
10.1 Transport __________________________________________________________ 7
10.2 Positioning ________________________________________________________ 7
10.3 Installation of the heat pump system________________________ 9
10.4 Installation of the heat consumer system__________________ 10
10.5 Fitting the casing parts________________________________________ 11
10.6 Removing the casing parts ___________________________________ 12
11. Power supply ����������������������������������������������� 12
11.1 Modules __________________________________________________________ 13
12. Commissioning ��������������������������������������������� 14
12.1 Heating curve adjustment during commissioning _______ 14
12.2 Operation and control _________________________________________ 14
12.3 Appliance handover ____________________________________________ 15
13. Maintenance ������������������������������������������������ 15
14. Troubleshooting �������������������������������������������� 15
14.1 DIP switch (WP-Typ)____________________________________________ 15
14.2 DIP switch (BA)__________________________________________________ 16
14.3 LEDs _______________________________________________________________ 16
14.4 Reset button _____________________________________________________ 16
15. Specification ������������������������������������������������ 17
15.1 Water and brine connection __________________________________ 17
15.2 Wiring diagrams for heat pump WPF 20 | 27______________ 18
15.3 Wiring diagrams for heat pump WPF 35 | 40______________ 19
15.4 Wiring diagrams for heat pump WPF 52 | 66______________ 20
15.5 Wiring diagrams for heat pump WPF 27 HT_______________ 21
15.6 Output diagrams WPF 20______________________________________ 22
15.7 Output diagrams WPF 27______________________________________ 24
15.8 Output diagrams WPF 27 HT__________________________________ 26
15.9 Output diagrams WPF 35______________________________________ 28
15.10 Output diagrams WPF 40______________________________________ 30
15.11 Output diagrams WPF 52______________________________________ 32
15.12 Output diagrams WPF 66______________________________________ 34
15.13 Data table ________________________________________________________ 36
GUARANTEE
ENVIRONMENT AND RECYCLING

SPECIAL INFORMATION
General information
www.stiebel-eltron.com WPF 20-66 | 3
SPECIAL INFORMATION
- The appliance may be used by children aged8
and up and persons with reduced physical, sen-
sory or mental capabilities or a lack of experience
and know-how, provided that they are supervised
or they have been instructed on how to use the
appliance safely and have understood the result-
ing risks. Children must never play with the ap-
pliance. Children must never clean the appliance
or perform user maintenance unless they are
supervised.
- Use a permanent connection to the power supply.
Ensure the appliance can be separated from the
power supply by an isolator that disconnects all
poles with at least 3mm contact separation.
- Maintain the minimum clearances to ensure trou-
ble-free operation of the appliance and facilitate
maintenance work.
- At the WPM, the COMMISSIONING/ SOURCE/
SOURCE MEDIUM parameter must be set to “eth-
ylene glycol” otherwise the frost stat will stop the
heat pump at temperatures below 7°C.
- Maintenance work, such as checking the electri-
cal safety, must only be carried out by a qualified
contractor.
- We recommend regular inspection (to establish
the current condition of the system), and main-
tenance by a qualified contractor if required (to
return the system to its original condition).
- Never interrupt the power supply, even outside
the heating period. The system‘s active frost pro-
tection is not guaranteed if the power supply is
interrupted.
- There is no need to shut the system down in
summer. The heat pump manager has an auto-
matic summer/winter changeover.
OPERATION
1. General information
The chapters „Special Information“ and „Operation“ are intended
for both the user and qualified contractors.
The chapter „Installation“ is intended for heating contractors.
Note
Read these instructions carefully before using the appli-
ance and retain them for future reference.
Pass on the instructions to a new user if required.
1.1 Relevant documents
Instructions for the WPM heat pump manager
Operating and installation instructions for system
components
1.2 Safety instructions
1.2.1 Structure of safety instructions
!
KEYWORD Type of risk
Here, possible consequences are listed that may result
from failure to observe the safety instructions.
 Steps to prevent the risk are listed.
1.2.2 Symbols, type of risk
Symbol Type of risk
Injury
Electrocution
1.2.3 Keywords
KEYWORD Meaning
DANGER Failure to observe this information will result in serious
injury or death.
WARNING Failure to observe this information may result in serious
injury or death.
CAUTION Failure to observe this information may result in non-seri-
ous or minor injury.
!

OPERATION
Safety
4| WPF 20-66 www.stiebel-eltron.com
1.3 Other symbols in this documentation
Note
Notes are bordered by horizontal lines above and below
the text. General information is identified by the symbol
shown on the left.
 Read these texts carefully.
Symbol Meaning
Material damage
(appliance, consequential and environmental damage)
Appliance disposal
 This symbol indicates that you have to do something. The ac-
tion you need to take is described step by step.
1.4 Units of measurement
Note
All measurements are given in mm unless stated oth-
erwise.
1.5 Standardised output data
Explanations to determine and interpret the specified standardised
output data.
1.5.1 Standard: EN 14511
The output data specifically mentioned in text, diagrams and
technical datasheets has been calculated according to the test
conditions of the standard shown in the heading of this section.
Generally, these standardised test conditions will not fully meet
the conditions found at the installation site of the system user.
Depending on the chosen test method and the extent to which
this method deviates from the conditions defined in the norm
shown in the heading of this section, any deviations can have a
considerable impact.
Further factors that have an influence on the test values are the
measuring equipment, the system configuration, the age of the
system and the flow rates.
A confirmation of the specified output data can only be obtained
if the test conducted for this purpose is also performed in ac-
cordance with the conditions defined in the norm shown in the
heading of this section.
2. Safety
2.1 Correct use
The appliance is designed for central heating within the applica-
tion limits given in the specification.
This appliance is designed for domestic use. It can be safely op-
erated by untrained personnel. The appliance can also be used in
a non-domestic environment, e.g. in a small business, as long as
it is used in the same way.
Any other use beyond that described shall be deemed inappro-
priate. Observation of this document is also part of the correct
use of the unit. Any changes or conversions to the appliance void
any warranty.
2.2 Safety instructions
Observe the following safety information and instructions.
Only recognised, qualified contractors may carry out the electrical
work and installation of the heating circuit.
The recognised contractor is responsible for adherence to
all currently applicable instructions during installation and
commissioning.
Operate this device only if it is fully installed and all safety
equipment is fitted.
!
WARNING Injury
The appliance may be used by children aged 8 and up
and persons with reduced physical, sensory or mental
capabilities or a lack of experience provided that they
are supervised or they have been instructed on how to
use the appliance safely and have understood the result-
ing risks. Children must never play with the appliance.
Children must never clean the appliance or perform user
maintenance unless they are supervised.
!
WARNING Injury
 For safety reasons, only operate the appliance with
the casing closed.
2.3 Test symbols
See type plate on the appliance.
!

OPERATION
Device description
www.stiebel-eltron.com WPF 20-66 | 5
3. Device description
3.1 Operational characteristics
The WPF is a heating heat pump designed as brine-water heat
pump. The heat pump extracts energy from the heat source
medium. i.e. brine. at a low temperature level. This extracted
energy is then transferred to the heating water at a higher
level. enriched with the energy drawn by the compressor.
Subject to the heat source temperature. the heating water can be
heated up to a flow temperature of 60 °C.
With heat pump type WPF HT. subject to the heat source
temperature. the heating water can be heated to a flow
temperature of up to 75 °C.
A modular operation is possible with the WPF.
3.2 Function
The heat source medium (brine) enters the heat pump evaporator.
There. heat is extracted from the medium. so it exits the heat
pump at a lower temperature.
The energy made useful through the heat pump is transferred to
the heating water inside the condenser.
Then the heating water transfers its energy to the heating circuit.
4. Control
The heat pump is exclusively controlled by the heat pump manager
WPM. Observe the instructions for the heat pump manager WPM.
!
Material losses
Never use the heat pump to dry the screed by means of
the underfloor heating system. The heating process and
the additional hours run as a consequence expend heat
source capacity. As a result, the heat source will not be
available for subsequent heating operation.
Never use the heat pump for drying screed, as this places an
excessive demand on the heat source and may cause it to be
damaged. Use the electric emergency/booster heater for the heat-
up program instead. For this, set the LOWERAPPLIMITHZG and
DUALMODETEMPHZG parameters to 30°C and start the heat-up
program. An exception should only be made if the installer of
the heat source system has written permission for screed drying.
5. Maintenance and care
!
Material losses
Maintenance work. such as checking the electrical safe-
ty. must only be carried out by a qualified electrician.
Protect the equipment from dust and dirt ingress during
building work.
We recommend regular inspection (to establish the current con-
dition of the system), and maintenance by a qualified contractor
if required (to return the system to its original condition).
A damp cloth is sufficient for cleaning all plastic and sheet steel
parts. Do not use abrasive or corrosive cleaning agents!
6. Troubleshooting
Fault Cause Remedy
There is no hot water or
the heating system stays
cold.
The fuse/MCB has blown/
responded.
Check the fuse/MCB in
your fuse box/distribu-
tion panel.
If you cannot remedy the fault, notify your qualified contractor.
To facilitate and speed up your enquiry, please provide the serial
number from the type plate. The type plate is located at the back
of the appliance.
Sample type plate
Montageanweisung beachten! Dichtheit geprüft! Made in Germany
*xxxxxxxxxxxxxxxxxx*
26_03_01_1736
1
1 Number on the type plate

INSTALLATION
Safety
6| WPF 20-66 www.stiebel-eltron.com
INSTALLATION
7. Safety
Only qualified contractors should carry out installation, commis-
sioning, maintenance and repair of the appliance.
7.1 General safety instructions
We guarantee trouble-free operation and operational reliability
only if the original accessories and spare parts intended for the
appliance are used.
7.2 Instructions. standards and regulations
Note
Observe all applicable national and regional regulations
and instructions.
8. Device description
8.1 WPF 20 | 27
D0000073455
1
7 6 5 4 3
2
1 Electrical terminals
2 Condenser
3 Drain & fill valve (heating)
4 Expansion valve
5 Compressor
6 Drain & fill valve (brine)
7 Evaporator
8.2 WPF 35 | 40 | 52 | 66
D0000073456
1
7 6 5 4 3
2
1 Electrical terminals
2 Condenser
3 Drain & fill valve (heating)
4 Expansion valve
5 Compressor
6 Drain & fill valve (brine)
7 Evaporator
8.3 WPF 27 HT
D0000073454
1
7 6 5 4 3
2
1 Electrical terminals
2 Condenser
3 Drain & fill valve (heating)
4 Expansion valve
5 Compressor
6 Drain & fill valve (brine)
7 Evaporator

INSTALLATION
Standard delivery
www.stiebel-eltron.com WPF 20-66 | 7
9. Standard delivery
Heat pumps are delivered in two shipping units.
- Standard heat pump device
- Casing parts
9.1 Accessories
- Heat pump manager WPM
- WPE heat pump extension
- Cylinder SBP 700 E
- Cylinder SBP 700 E SOL
- Kit WPVB
- Remote control for heating systems FE 7
- Remote control for heating systems FET
- TAF PT immersion/contact sensor
- Heat transfer medium (concentrate) (10 litre can)
- Heat transfer medium (concentrate) (30 litre can)
10. Installation
10.1 Transport
To protect the equipment against damage. transport it vertically
inside its packaging. Storage and transport at temperatures below
– 20 °C and in excess of + 50 °C are not permissible.
In the top of the frame are four holes for fitting lifting eyes M 12
where the equipment can be lifted.
The casing parts are delivered in a separate package. and these
are fitted to the device at the place of installation.
10.1.1 Dismantling for reduced depth
Note
In order to transport the appliance through an 80cm wide
door, the connectors and terminal box must be removed.
D0000073483
 Undo the screws on the four connectors.
 Push the four connectors into the appliance until the connec-
tors no longer protrude beyond the back of the appliance.
D0000073484
 Undo the screws on the terminal box.
798
D0000073481
10.2 Positioning
Level the device horizontally by adjusting the equipment feet.
To prevent the heat pump from being damaged by frost when
installing outdoors or in a room that is not free from the risk of
frost, fit and electrically connect the immersion/contact sensor
TAFPT as a frost protection facility into the heating return of
the heat pump. Electrical connection and sensor installation see
chapter „Power supply“.
 Observe the minimum clearances.

INSTALLATION
Installation
8| WPF 20-66 www.stiebel-eltron.com
≥500
≥500
≥500
≥500
≥1000
D0000019260
2 heat pumps may also be stacked.
 For this, use the WPVB joining set.
1154 1115
2269
D0000020355
10.2.1 External installation
We recommend foundations as base for the device.
26_03_01_0803
To facilitate connection to the appliance, we recommend using
flexible supply lines in the case of outdoor installation.
Route all supply lines inside a conduit that is free from frost (pro-
tective pipe).
Allow the conduits for the supply lines to protrude slightly above
the foundations. Ensure that no water can enter the conduits.
Protect the connection area at the back panel against all weather
and solar influences.
10.2.2 Internal installation
The room where the WPF is to be installed must meet the following
conditions:
- Load-bearing floor. For the weight of the WPF. see
“Specification”.
- For a quiet heat pump operation on floating screeds. recess
the screed and the anti-vibration insulation around the
installation location
of the heat pump.
1 2 3 54
26_03_01_1466
1 Concrete ceiling
2 Impact sound insulation
3 Floating screed
4 Floor covering
5 Recess

INSTALLATION
Installation
www.stiebel-eltron.com WPF 20-66 | 9
- The room must not be subject to a risk of explosions arising
from dust. gases or vapours. Never allow the floor area
and the volume of the installation room to be less than the
minimum values listed in the table.
Typ Volume Floor area
WPF 20 14 m³ 5 m²
WPF 27 | WPF 27 HT 16 m³ 7 m²
WPF 35 23 m³ 9 m²
WPF 40 23 m³ 9 m²
WPF 52 28 m³ 11 m²
WPF 66 33 m³ 13 m²
- When installing the WPF in a boiler room together with
other heating equipment ensure. that the operation of other
heating equipment will not be impaired.
10.2.3 Sound emission
Never install the heat pump immediately below or adjacent to
bedrooms. Insulate pipes through walls and ceilings against
structure-borne noise transmission.
10.3 Installation of the heat pump system
Design the heat source system for the brine-water heat pump in
accordance with Stiebel Eltron technical guides.
Permitted brine:
- Heat transfer medium as concentrate on an ethylene glycol
base, part no: 231109
- Heat transfer medium as concentrate on an ethylene glycol
base, part no: 161696
10.3.1 Circulation pump and required flow rate
Use a circulation pump with compound-filled windings to supply
the brine. to prevent an earth short circuit through condensation
in the electrical part of the pump (cold water version).
Size the circulation pump in accordance with the system-specific
conditions. i.e. nominal flow rate and pressure drop must be taken
into consideration (see “Specification”).
An adequate flow rate must be safeguarded at every possible
brine temperature. i.e.:
Size the nominal flow rate at brine temperature 0 °C with a
tolerance of + 10 %.
10.3.2 Connection and filling with brine
Before connecting the heat pump, check the heat source circuit
for leaks and flush it thoroughly with brine.
Calculate the volume of the heat source circuit. You can obtain the
brine volume inside the heat pump from the “Data table” table.
The overall volume is equal to the required amount of brine made
by mixing undiluted mono ethylene glycol and water. The chloride
content of the water must not exceed 300 ppm.
Mixing ratio
The brine concentration varies when using a ground collector or
a geothermal probe as a heat source.
The mixing ratio can be found in the table below.
Ethylene glycol Water
Geothermal probe 25 % 75 %
Ground collector 33 % 67 %
After filling the system with brine and prior to commissioning, vent
the brine circuit until there is no more air left in it.
10.3.3 Check the brine concentration:
 Determine the density of the ethylene glycol/water mixture,
e.g. with a hydrometer.
Using the actual density and temperature, you can check the actual
concentration in the diagram.
Note
The quoted details refer to ethylene glycol (see "Speci-
fication").
1,10
1,09
1,08
1,07
1,06
1,04
1,03
1,02
1,01
1,00
0,99
0,98
-20 0 20 40 60 80 100
50 Vol.-%
0
1,05
40
33
30
25
20
10
A
26_03_01_1914
X Temperature [°C]
Y Density [g/cm³]
A Frost protection [°C]
10.3.4 Checking the flow rate (during heat pump
commissioning)
Check the flow and return temperatures of the heat source. For
this. determine the temperature differential by measuring the
temperature under the thermal insulation on both flow and return
pipes of the heat pump.
The diagram shows the temperature spread at the nominal flow
rate.

INSTALLATION
Installation
10 | WPF 20-66 www.stiebel-eltron.com
6
1
2
5
4
3
2
1
-5 0 5 10 15 20
84_03_01_0017
Y Temperature differential
X Source inlet temperature
1 Brine = heating flow 35 °C
2 Brine = heating flow 50 °C
!
Material losses
At the WPM set parameter COMMISSIONING/ SOURCE in
the commissioning list to “Ethylene glycol”. otherwise
the frost stat would stop the heat pump at temperatures
below 7 °C. The source inlet temperature can be checked
on the display of the WPM under the INFO/ SYSTEM/
SOURCE system parameter.
10.4 Installation of the heat consumer system
The layout of the connection material on the heating side has to
be done according to the evaporator and condensator materials
(Technical Datas) to avoide corrosion.
Implement the heat consumer system (heating circuit) in accord-
ance with current technical rules. For safety equipment in heating
systems. consult the DIN EN 12828.
Ensure the correct connection of the heating flow and return.
Protect the heating water lines against frost and moisture (only
in case of external installation). Protect flow and return lines in
external installations with an adequate amount of thermal insu-
lation against frost and by routing them inside a conduit against
moisture.
Maintain the required insulation thickness in accordance with the
Heating System Order [or local regulations].
The integral frost protection control (inside the heat pump). that
automatically starts the circulation pump in the heat pump circuit
at + 8 °C and thereby safeguards circulation in all water-bearing
components. offers additional frost protection. The heat pump is
started automatically no later than when the temperature inside
the buffer cylinder drops below + 5 °C.
Prior to connecting the heat pump. check the heating system for
leaks. flush it thoroughly. fill and carefully vent it.
10.4.1 Oxygen diffusion
!
Material losses
Do not use open vented heating systems. Use oxygen
diffusion-proof pipes in underfloor heating systems with
plastic pipework.
In underfloor heating systems with plastic pipes that are per-
meable to oxygen and in open vented heating systems, oxygen
diffusion may lead to corrosion on the steel components of the
heating system (e.g. on the indirect coil of the DHW cylinder, on
buffer cylinders, steel radiators or steel pipes).
 With heating systems that are permeable to oxygen, separate
the heating system between the heating circuit and the buff-
er cylinder.
!
Material losses
The products of corrosion (e.g. rusty sludge) can settle in
the heating system components and can result in a lower
output or fault shutdowns due to reduced cross-sections.
10.4.2 Filling the heating system
Water quality
A fill water analysis must be available prior to charging the sys-
tem. This may, for example, be requested from the relevant water
supply utility.
!
Material losses
To avoid damage as a result of scaling, it may be neces-
sary to soften or desalinate the fill water. The fill water
limits specified in chapter "Specification / Data table"
must always be observed.
 Recheck these limits 8-12 weeks after commission-
ing and as part of annual system maintenance.
Note
With conductivity of >1000μS/cm, desalination treatment
is recommended in order to avoid corrosion.
Note
Suitable appliances for water softening and desalinating,
as well as for charging and flushing heating systems, can
be obtained via trade suppliers.
Note
If you treat the fill water with inhibitors or additives, the
same limits as for desalination apply.
10.4.3 Buffer cylinder
A buffer cylinder is recommended to ensure a trouble-free heat
pump operation. The buffer cylinder provides hydraulic separation
of the volume flow in the heat pump circuit and the heating circuit.
The flow rate in the heat pump remains constant if. for example.
the flow rate in the heating circuit is reduced by thermostatic
valves.

INSTALLATION
Installation
www.stiebel-eltron.com WPF 20-66 | 11
10.4.4 Circulation pump (cylinder primary pump)
When using a buffer cylinder. observe the pressure drop of the
evaporator. of the connecting lines. bends. valves etc. in sizing the
circulation pump to be installed.
10.4.5 Circulation pump (heating circuit pump)
Where no buffer cylinder is used. size the circulation pump
on the heating side taking the condenser pressure drop into
consideration. The flow rate at DT = 10 K (see “Specification”) of
the heat pump must be assured under all operating conditions of
the heating system through the installation of an overflow valve.
10.4.6 Second external heat source
For dual-mode heating systems. always connect the heat pump
into the return of the second heat source (e.g. oil fired boiler).
High heating water temperature: In dual-mode heating systems.
the return water from the second heat source can flow through
the heat pump. immediately after it has been switched off. with
a max. temperature of 60 °C. The temperature may be 65 °C no
earlier than ten minutes after the heat pump has been shut down.
10.4.7 Heat meter
Observe the additional pressure drop when installing heat meters
on the heating side. The sieves inside the heat meters are easily
blocked by dirt particles in the heating circuit. further increasing
the pressure drop.
10.5 Fitting the casing parts
Fitting the plinth trim and side covers
26_03_01_0791
1
1
2
1.
2. 3.
 Hook the plinth facia 1into the device frame and secure each
with three screws
 Position the covers 2and secure each with two screws to the
sides.
Fitting the shield and control panel frame
26_03_01_0792
2
1
 Fix the guard plate 1with four screws. The both in the front
with the toothed locked washer.
 Secure the control panel frame 2with five screws.
Fitting the side panels and sound insulation
26_03_01_0793
1
1
2
 Hook the side panels 1from the top into the slots and hooks
provided and secure with one screw each at the bottom of
the control panel frame.
 Install sound insulation 2in the control panel frame

INSTALLATION
Power supply
12 | WPF 20-66 www.stiebel-eltron.com
Fit front panel
C26_03_01_0795
 Hook the bottom of the front panel into the control panel
frame. pivot it towards the frame and secure with one screw
on each side.
Fit centre cover
C26_03_01_0794
 Position the cover at the front of the device and push it back;
then secure it with two screws.
Note
Make the power supply before the centre cover and front
panel are fitted.
10.6 Removing the casing parts
The casing parts are removed in reverse order.
11. Power supply
Notify your local power supply utility of the electrical connection.
Only qualified electricians must carry out the installation in
accordance with these instructions.
WARNING Electrocution
Before any work. isolate the equipment from the power
supply at the control panel.
WARNING Electrocution
The connection to the power supply must be in the form
of a permanent connection. Ensure the appliance can be
separated from the power supply by an isolator that dis-
connects all poles with at least 3mm contact separation.
This requirement can be met by using contactors, circuit
breakers, fuses/MCBs, etc.
Observe VDE 0100 [or local regulations] and the regulations of your
local power supply utility.
The terminals are located above the control panel. Remove the lid
to enable the equipment to be connected.
The following are connected at the terminals:
- the power supply of the IWS heat pump control unit
- the compressor power supply
- the brine pump power supply
- the BUS cable (J-Y (St) 2x2x0.8)
Ensure that High. Low and Ground are correctly connected.
- the enable signal for the stand-alone operation at terminal
X4/2. For this. remove the jumper between X4/L and X4/2.
The IWS (integral heat pump controller) is a PCB that is fitted as
standard into the heat pump control panel. The IWS controls the
contactors of the compressors and the starting current limiter.
receives the signal inputs for high pressure. low pressure and
central faults and contains the BUS interface to the WPM.
Use appropriate cables in accordance with local regulations for
all connections. For this. observe the Electrical details in “Speci-
fication” and the Electrical connection diagram.
Check the strain relief function.
Observe the operating instructions for the WPM heat pump man-
ager.
Connect the circulation pump for the heat consumers in accord-
ance with the electrical connection diagram or the engineering
documentation.
In case of external installation. use only weather-proof connecting
cables to VDE 0100 [or local regulations]. As a minimum require-
ment. use cables with rubber sheathing with the identification
60245 IEC 57. Route all lines inside a conduit (protective pipe).
To prevent the heat pump from being damaged by frost when
installing outdoors or in a room that is not free from the risk of
frost, fit immersion/contact sensors TAFPT into the heating return
of the heat pump. The contact sensor is electrically connected at
terminals X2/4 and X2/5.
The heating circuit pumps are started when the heating-return
temperature falls to +8 °C. The reverse switching hysteresis is 4 K.

INSTALLATION
Power supply
www.stiebel-eltron.com WPF 20-66 | 13
Installation as contact sensor
D0000070237
 Clean the pipe.
Note
The recesses on the retaining clip are of different sizes.
 Press the smaller recess on the retaining clip into one of the
notches on the sensor.
 Press the larger recess of the retaining clip onto the sensor.
 Apply heat conducting paste to the sensor.
 Secure the sensor with the retaining clip and the cable tie.
STAND-ALONE operation
In emergencies. this heat pump can also operate without the heat
pump manager (see troubleshooting).
Route all connecting cables and sensor leads through the apertures
in the back panel.
11.1 Modules
When using a modular approach. connect the individual heat
pumps via terminal BUS 1, 2, 3. Ensure that High, Low and Ground
are correctly connected at the WPM as well as at the heat pump.
Power supply WPF 20, WPF 27, WPF 35, WPF 40, WPF 52, WPF
66, WPF 27 HT
Störung
X3
X5
X4
3/N/PE
~400V 50Hz
3/N/PE
~400V 50Hz
~230V 50Hz
X2
WPM
BUS / Sensor
26_03_01_0796
X3 Compressor (HP)
L1, L2, L3, N, PE Power supply
X2 Safety extra low voltage
B6 Temperature sensors
B6 Temperature sensors
⊥Bus earth
L BUS Low
H Bus high
X4 Control voltage
L, N, PE Power supply
Ext. Steuer. (External
control)
Stand-alone operation
ON Compressor output signal
Störung (Fault) Output signal fault
X5 Brine pump
L1, L2. L3, N, PE Power supply
Note
For every appliance fault, the “fault” output issues a
230V signal. The output passes the signal on to the ex-
ternal controller.
In the case of temporary faults, the output switches the
signal through for a specific time.
In the case of faults that result in a permanent appliance
shutdown, the output switches through permanently.
Note
As soon as the compressor is running, the "ON" output
issues a 230V signal.

INSTALLATION
Commissioning
14 | WPF 20-66 www.stiebel-eltron.com
12. Commissioning
Note
Only applies to WPF27HT.
When quick start is used, the starting resistors are not
patched in.
 Do not use quick start when measuring the starting
current.
Only approved contractors may commission this equipment and
instruct the owner in its use.
Commissioning the WPF must be carried out in accordance with
these installation instructions and the instructions for the WPM
heat pump manager. Our customer service can assist in the
commissioning. which is chargeable.
Where this heat pump is used in an installation that is intended
for commercial use. the rules of the relevant Health & Safety at
Work Act may come into play. For further details. check your local
authorising body. The function of the device. including those of
any safety equipment fitted is tested at the factory.
After commissioning. the installer should complete the
commissioning report contained in these instructions.
Check the following prior to commissioning:
Heating system
- Was the heating system filled to the correct pressure. and
was the quick-acting air vent valve opened?
Temperature sensor
- Were the outside temperature and the return temperature
sensor (in conjunction with a buffer cylinder) correctly
positioned and connected?
Power supply
- Was the mains power supply properly connected?
!
Material losses
The compressor in the appliance can only turn in one
direction. If the appliance is not connected correctly. the
compressor remains in operation for 30 seconds then
switches off.
In this case the heat pump manager displays the fault message
„no output“. Two phases should then be interchanged to alter the
direction of rotation.
When everything has been implemented correctly. the system
can be heated to its maximum operating temperature and vented
once again.
!
Material losses
Observe the maximum system temperature in underfloor
heating systems.
12.1 Heating curve adjustment during
commissioning
The efficiency of a heat pump decreases as the flow temperature
rises. Adjust the heating curve carefully. Heating curves that are
set too high cause the zone valves or thermostatic valves to close,
which may lead to the minimum flow rate required for the heating
circuit not being achieved.
The following steps will help you to adjust the heating curve cor-
rectly:
 Fully open thermostatic or zone valves in a lead room (e.g.
living room or bathroom).
We do not recommend installing thermostatic or zone valves
in the lead room. Control the temperature for these rooms
via a remote control.
 At different outside temperatures (e.g. -10 °C and +10 °C),
adjust the heating curve so the required temperature is
achieved in the lead room.
Standard values to begin with:
Parameter Underfloor heating
system
Radiator heating
system
Heating curve 0.4 0.8
Controller dynamics 10 10
Comfort temperature 20 °C 20 °C
If the room temperature in spring and autumn is too low (outside
temperature approx. 10 °C ), the COMFORT TEMPERATURE param-
eter must be raised.
Note
If no remote control is installed, raising the COMFORT
TEMPERATURE parameter leads to a parallel offset of the
heating curve.
If the room temperature is not high enough at low outside tem-
peratures, increase the heating curve parameter.
If the heating curve parameter has been raised, adjust the zone
valve or thermostatic valve in the lead room to the required tem-
perature when outside temperatures are high.
Note
Never reduce the temperature in the entire building by
closing all zone or thermostatic valves; instead use the
setback programs.
12.2 Operation and control
A WPM heat pump manager is required to operate the heat pump.
It regulates the entire heating system. All necessary adjustments
prior and during operation are made on this device.
Only qualified contractors must make adjustments listed in the
commissioning report of the WPM heat pump manager.

INSTALLATION
Maintenance
www.stiebel-eltron.com WPF 20-66 | 15
!
Material losses
The system does not need to be shut down during
summer. as the WPM implements an automatic summer/
winter changeover. If the system is. nevertheless. to be
shut down. set the WPM to standby. That way the safety
functions that protect the system remain enabled (e.g.
frost protection).
Drain the water side of the equipment. if the heat pump is taken
out of use at a location subject to a risk of frost or if it is installed
externally.
Drain the liquid contained inside the evaporator via the fill & drain
valve that becomes accessible after removing the r.h. side panel.
12.3 Appliance handover
Explain the function of the appliance to users and familiarise them
with its operation.
Note
Hand over these operating and installation instructions
to the user for safe-keeping. All information in these
instructions must be closely observed. The instructions
provide information on safety, operation, installation and
maintenance of the appliance.
13. Maintenance
WARNING Electrocution
Before any work. isolate the equipment from the power
supply at the control panel.
!
Material losses
Check the refrigerant circuit of the heat pump WPF 20, 27,
35, 40, 52, 66 annually for tightness in accordance with
EU Directive 517/2014.
Document tightness tests in the service record.
We recommend a regular inspection (to establish the current con-
dition of the system), and maintenance if required (to return the
system to its original condition).
If heat meters are installed. frequently clean their sieves. which
block easily.
When the heat pump operation is impaired (high pressure limiter
responds) through deposits of corrosion by-products (rust sludge)
inside the condenser. only dissolving them by means of solvents
used by our customer service will remove this problem.
A permanently set motor overload relay is built into the com-
pressor.
14. Troubleshooting
WARNING Electrocution
Before any work, isolate the appliance from the power
supply at the control panel.
Checking the IWS settings
BA
3
2
1
4
26_03_01_0661
1 LEDs
2 DIP switch (BA)
3 Reset button
4 DIP switch (heat pump)
The control panel with the “Internal heat pump controller” (IWS)
becomes accessible after removing the front hood. The following
list the adjustments of the IWS required for the WPF:
14.1 DIP switch (WP-Typ)
Factory setting
WP - Typ
ON
1234
D0000057058
 Check whether the DIP switch is set correctly.

INSTALLATION
Troubleshooting
16 | WPF 20-66 www.stiebel-eltron.com
14.2 DIP switch (BA)
Switches 1, 2 and 3 have no relevance to the WPF.
Position switch 4
Switch ON : STAND-ALONE operation
STAND-ALONE operation is only possible if a heat pump type
has been allocated to the WPM under parameter DIAGNOSIS/
SYSTEM/ HEAT PUMP TYPES.
Should the WPM heat pump manager develop a fault. the heat
pump can be operated in STAND-ALONE mode in an emergency.
In this operating mode. there is no communication with the WPM.
The heat pump regulates to a fixed temperature: it starts up at
50 °C and shuts down at 55 °C. For this. 230 V must be applied to
terminal X4/2. and a contact sensor AVF 6 connected as a return
temperature sensor at sensor terminals X2/4 and X2/5. The
sensor must be connected to the heating return (chapter Device
description). The operating mode is indicated by the green LED
on the right.
!
Material losses
For STAND-ALONE operation remove the jumper between
X4/1 and X4/2.
14.3 LEDs
Red LED (left)
Faults indicated by the LED:
- High pressure fault
- Low pressure fault
- Hardware fault on the IWS (see notification list for the heat
pump manager)
Fault Cause Remedy
The appliance stops and
restarts after the idle
time has expired. The red
LED flashes.
There is a heat pump
fault.
Check the fault message
on the WPM.
Find the solution in the
WPM instructions (fault
list). Reset the IWS.
The appliance shuts
down permanently. The
red LED is constantly illu-
minated.
Five faults have oc-
curred within two
hours of compressor
runtime.
Check the fault message
on the WPM.
Find the solution in the
WPM instructions (fault
list). Reset the IWS.
Green LED (centre)
The LED flashes during initialisation and illuminates constantly
after the bus address has been assigned successfully. Connection
to the WPM has been established.
Green LED (right)
Illuminates steady if STAND-ALONE operation has been selected.
14.4 Reset button
If initialised in error, please refer to “Commissioning/ Reset op-
tions IWS” in the heat pump manager operating and installation
instructions.

INSTALLATION
Specication
www.stiebel-eltron.com WPF 20-66 | 17
15. Specification
15.1 Water and brine connection
1250
860
340
470
772
900
1150
720
600
480
360
e01
e02
f01
f02
b01
D0000016833
WPF 20 WPF 27 WPF 35 WPF 40 WPF 52 WPF 66 WPF 27 HT
b01 Entry electrical cables
e01 Heating flow Male thread G 2 G 2 G 2 G 2 G 2 G 2 G 2
e02 Heating return Male thread G 2 G 2 G 2 G 2 G 2 G 2 G 2
f01 Heat source flow Male thread G 2 G 2 G 2 G 2 G 2 G 2 G 2
f02 Heat source return Male thread G 2 G 2 G 2 G 2 G 2 G 2 G 2

INSTALLATION
Specication
18 | WPF 20-66 www.stiebel-eltron.com
15.2 Wiring diagrams for heat pump WPF 20 | 27
8
X2
K1
A2
A1
6
7
Q1
2 1
6
5 4 3
L
11
2 1
suB
Heißgas
12 10
9 8 7
H
Einfrierschutz
3
HD/ND Solepumpe N
5 4 3 2 1
3
4 5
L
M1
M
3
X3
X5
A2
9
10 11 12 13
X1
Fü relh
2 1
L1
L2 L3 N
K4
6
4
2
1 3 5
K1
6
4
2
1 3 5
14
L
N
X4
euetS.txE r.
1/N /PE AC 50Hz 230V
F2
> p
2
3/N/PE AC 50Hz 400V
3/N/PE AC 50Hz 400V
321
4
5
X23
X34 N3
X23
X29
X33
X30
21
1
X24
X24
C
T1
S
T2
R
T3
L1
L2 L3 N
K4
A1
A2
Q1
A2
A1
Q1
2
4
6
5
3
1
L3
L2
L1
T1
T2
T3
A1
A2
T <
E2
1 2 3
Anschluss Solepumpe
L
H
Kleinspannung
BUS
B6
B6
NO
F9
Z2
6
4
2
135
br ws sw br ws sw
3
4 5
2 1
X35
6
P
I
P
I
P3 P1
1 1
2 2
12-18V
X28
B5
3
rungötS
26_03_01_0853_d
A2 Integral heat pump controller IWS B5 Hot gas temperature sensor B6 Frost sensor (only for ext. inst. or inst. in a room
not free from the risk of frost)
E2 Oil sump heater F2 High pressure limiter F9 Solar pump MCB K1 Safety contactor K4 Brine pump contactor
M1 Compressor motor
N3 Temp. controller - oil sump heater P1 High pressure transducer P3 Low pressure transducer
Q1 Softstart contactor X1 Terminals X2 LV terminal
X3 Heat pump - mains X4 Control voltage terminals X5 Brine pump terminals X23 Power supply earth terminal block X24 Power supply earth screw X28 Plug-in connector terminal strip
X29 Plug-in connector IWS 12-PIN X30 Plug-in connector IWS 3-PIN X33 Plug-in connector IWS 5-PIN X34 Plug-in connector terminal strip - oil sump heater
X35 Plug-in connector IWS 6-PIN Z2 Anti-interference capacitor

INSTALLATION
Specication
www.stiebel-eltron.com WPF 20-66 | 19
15.3 Wiring diagrams for heat pump WPF 35 | 40
8
X2
K1
A2
A1
6
7
Q1
2 1
6
5 4 3
L
11
2 1
suB
Heißgas
12 10
9 8 7
H
Einfrierschutz
3
HD/ND Solepumpe N
5 4 3 2 1
3
4 5
L
X3
X5
A2
9
10 11 12 13
X1
Fü relh
2 1
L1
L2 L3 N
K4
6
4
2
1 3 5
K1
6
4
2
1 3 5
14
L
N
X4
euetS.txE r.
1/N /PE AC 50Hz 230V
F2
> p
2
3/N/PE AC 50Hz 400V
3/N/PE AC 50Hz 400V
321
4
5
X23
X34 N3
X23
X29
X33
X30
21
1
X24
L1
L2 L3 N
K4
A1
A2
Q1
A2
A1
T <
E2
1 2 3
Anschluss Solepumpe
L
H
Kleinspannung
BUS
B6
B6
NO
F9
Z2
6
4
2
135
br ws sw br ws sw
3
4 5
2 1
X35
6
P
I
P
I
P3 P1
1 1
2 2
12-18V
X28
B5
M1
M
3
6
4
2
1 3 5
X24
C
T1
S
T2
R
T3
A2
A1
K2
Q1
2
4
6
5
3
1 L3
L2
L1
T1
T2
T3
K2
23
24
A1
A2
X1 1 4
Drossel
Z1
Z1/schräg rechts Z1/schräg links
3
törungS
26_03_01_0806_d
Brine pump connection
Low voltage
A2 Integral heat pump controller IWS B5 Hot gas temperature sensor B6 Frost sensor (only for ext. inst. or inst. in a room
not free from the risk of frost)
E2 Oil sump heater F2 High pressure limiter F9 Solar pump MCB K1 Safety contactor K2 Compressor contactor K4 Brine pump contactor
M1 Compressor motor
N3 Temp. controller - oil sump heater
P1 High pressure transducer P3 Low pressure transducer Q1 Softstart contactor X1 Terminals X2 LV terminal
X3 Heat pump - mains X4 Control voltage terminals X5 Brine pump terminals X23 Power supply earth terminal block X24 Power supply earth screw X28 Plug-in connector terminal strip
X29 Plug-in connector IWS 12-PIN
X30 Plug-in connector IWS 3-PIN X33 Plug-in connector IWS 5-PIN X34 Plug-in connector terminal strip - oil sump heater X35 Plug-in connector IWS 6-PIN Z1 Anti-interference filter Z2 Anti-interference capacitor

INSTALLATION
Specication
20 | WPF 20-66 www.stiebel-eltron.com
15.4 Wiring diagrams for heat pump WPF 52 | 66
8
X2
K1
A2
A1
6
7
Q1
2 1
6
5 4 3
L
11
2 1
suB
Heißgas
12 10
9 8 7
H
Einfrierschutz
3
HD/ND Solepumpe N
5 4 3 2 1
3
4 5
L
X3
X5
A2
9
10 11 12 13
X1
Fü relh
2 1
L1
L2 L3 N
K4
6
4
2
1 3 5
K1
6
4
2
1 3 5
14
L
N
X4
euetS.txE r.
1/N /PE AC 50Hz 230V
F2
> p
2
3/N/PE AC 50Hz 400V
3/N/PE AC 50Hz 400V
321
4
5
X23
X34 N3
X23
X29
X33
X30
21
1
X24
L1
L2 L3 N
K4
A1
A2
Q1
A2
A1
T <
E2
123
Anschluss Solepumpe
L
H
Kleinspannung
BUS
B6
B6
NO
F9
Z2
6
4
2
135
br ws sw br ws sw
3
4 5
2 1
X35
6
P
I
P
I
P3 P1
11
22
12-18V
X28
B5
M1
M
3
6
4
2
1 3 5
X24
C
T1
S
T2
R
T3
A2
A1
K2
Q1
2
4
6
5
3
1
L3
L2
L1
T1
T2
T3
K2
23
24
A1
A2
X1 14
Drossel
Z1
Z1/schräg rechts Z1/schräg links
T1 T2
F7
>u
M2 M1
3
Störung
D0000072637
Brine pump connection
Restrictor
Low voltage
BUS
Sensor
BUS
Brine pump HD/ND
Z1/slanting left
Z1/slanting right
Fault
Ext. control unit
ON
A2 Integral heat pump controller IWS B5 Hot gas temperature sensor B6 Frost sensor (only for ext. inst. or inst. in a room
not free from the risk of frost)
E2 Oil sump heater F2 High pressure limiter F7 Protective motor switch. internal F9 Solar pump MCB K1 Safety contactor K2 Compressor contactor K4 Brine pump contactor
M1 Compressor motor
N3 Temp. controller - oil sump heater P1 High pressure transducer P3 Low pressure transducer Q1 Softstart contactor X1 Terminals X2 LV terminal
X3 Heat pump - mains X4 Control voltage terminals X5 Brine pump terminals X23 Power supply earth terminal block X24 Power supply earth screw X28 Plug-in connector terminal strip
X29 Plug-in connector IWS 12-PIN X30 Plug-in connector IWS 3-PIN X33 Plug-in connector IWS 5-PIN X34 Plug-in connector terminal strip - oil sump heater X35 Plug-in connector IWS 6-PIN Z1 Anti-interference filter Z2 Anti-interference capacitor