Bosch Compress 3400i AWS User manual

6721852066 (2023/01) GB/IE
Installation manual
Indoor Unit for Air to Water Heat Pump
Compress 3400i AWS
CS3400iAWS 10 E

Table of contents
Compress 3400i AWS – 6721852066 (2023/01)
2
Table of contents
1 Explanation of symbols and safety instructions . . . . . . . . . . . 3
1.1 Explanation of symbols . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.1 Refrigerant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Water quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Product description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Supplied parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Information on the indoor unit. . . . . . . . . . . . . . . . . . . . . 7
3.3 Declaration of Conformity . . . . . . . . . . . . . . . . . . . . . . . . 7
3.4 Type plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.5 Functional principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.6 Product overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.7 Product dimensions and minimum clearances. . . . . . . . 8
3.8 Connection dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Preparing for installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1 Considerations for assembling the indoor unit . . . . . . . 9
4.2 Heating system minimum volume and flow . . . . . . . . . . 9
5 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1 Transport and storage . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2 Insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.3 Checklist. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.4 Removing the front cover of the indoor unit . . . . . . . . . 10
5.5 Assembling the drip tray . . . . . . . . . . . . . . . . . . . . . . . . 11
5.6 Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.6.1 Connectingtheindoorunitwith integratedelectric
booster heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.6.2 Filling the outdoor unit, indoor unit and heating
system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.6.3 Primary circulation pump (PC0) . . . . . . . . . . . . . . . . . . 13
5.6.4 Heating circuit pump (PC1). . . . . . . . . . . . . . . . . . . . . . 13
5.7 Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.7.1 Connecting the indoor unit . . . . . . . . . . . . . . . . . . . . . . 14
5.7.2 Connections to installer module of the indoor unit . . . . 15
5.7.3 CAN-BUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.7.4 EMS BUS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.7.5 Fitting temperature sensors . . . . . . . . . . . . . . . . . . . . . 17
5.7.6 External connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.7.7 Terminals for electrical connections . . . . . . . . . . . . . . . 18
6 Commissioning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.1 Commissioning checklist. . . . . . . . . . . . . . . . . . . . . . . . 18
6.2 Venting the indoor unit. . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.3 Adjusting the operating pressure of the heating
system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.4 Pressure switch and overheating protection . . . . . . . . 20
6.5 Function test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.5.1 Operating temperatures . . . . . . . . . . . . . . . . . . . . . . . . 20
7 Operation without the outdoor unit (individual
operation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
8 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
8.1 Particle filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
8.2 Replacing components . . . . . . . . . . . . . . . . . . . . . . . . . 21
9 Installation of accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.1 CAN-BUS accessories . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.2 EMS-BUS for accessories . . . . . . . . . . . . . . . . . . . . . . . 22
9.3 External inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
9.4 Installation of the domestic hot water cylinder . . . . . . 23
9.5 DHW cylinder temperature sensor TW1. . . . . . . . . . . . 24
9.6 Diverter valve VW1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
9.7 DHW circulation pump PW2 (accessory). . . . . . . . . . . 25
9.8 Several heating circuits (with heating circuit
module) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
9.9 Installation with swimming pool . . . . . . . . . . . . . . . . . . 25
9.10 Connect-Key K 30 RF. . . . . . . . . . . . . . . . . . . . . . . . . . . 26
10 Environmental protection and disposal . . . . . . . . . . . . . . . . . 26
11 Technical information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
11.1 Specifications - Indoor unit with integrated
electric booster heater . . . . . . . . . . . . . . . . . . . . . . . . . 26
11.2 Primary circulation pump diagram (PC0) . . . . . . . . . . 27
11.3 System solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
11.3.1 Explanations of the system solutions . . . . . . . . . . . . . . 28
11.3.2 Bypass of the heating system . . . . . . . . . . . . . . . . . . . . 29
11.3.3 System with integrated booster heater, DHW and
heating circuit without bypass and mixing valve . . . . . 30
11.3.4 System with integrated booster heater, DHW and
heating circuit with or without mixing valve and
with bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
11.3.5 System with integrated booster heater, buffer,
DHW and heating circuit with or without mixing
valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
11.3.6 Explanation of symbols . . . . . . . . . . . . . . . . . . . . . . . . . 33
11.4 Wiring diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
11.4.1 Installer module of indoor unit with integrated
electric booster heater . . . . . . . . . . . . . . . . . . . . . . . . . 34
11.4.2 CAN & EMS BUS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
11.4.3 Wiring diagram for 5.85kW 230V~ electric
booster heater, CS3400iAWS 4-10 OR-S 230V~ . . . . 36
11.4.4 Wiring diagram for 5.85kW 3N ~ electric booster
heater, CS3400iAWS 4-10 OR-S 230V~. . . . . . . . . . . 36
11.4.5 400V 3N~ indoor unit with 230V~ outdoor unit . . . . . 37
11.4.6 Connection alternative for EMS bus . . . . . . . . . . . . . . . 38
11.4.7 EVU/SG wiring diagram for the indoor unit with an
integrated electric booster heater . . . . . . . . . . . . . . . . 38
11.4.8 Photovoltaic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
11.5 Cable scheme. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
11.6 Measurements from temperature sensors . . . . . . . . . . 39
12 System Commissioning Report . . . . . . . . . . . . . . . . . . . . . . . . 40
13 Maintenance protocol, refrigerant (log book) . . . . . . . . . . . 41

Explanation of symbols and safety instructions
3
Compress 3400i AWS – 6721852066 (2023/01)
1 Explanation of symbols and safety instructions
1.1 Explanation of symbols
Warnings
In warnings, signal words at the beginning of a warning are used to
indicate the type and seriousness of the ensuing risk if measures for
minimizing danger are not taken.
The following signal words are defined and can be used in this document:
DANGER
DANGER indicates that severe or life-threatening personal injury will
occur.
WARNING
WARNING indicates that severe to life-threatening personal injury may
occur.
CAUTION
CAUTION indicates that minor to medium personal injury may occur.
NOTICE
NOTICE indicates that material damage may occur.
Important information
The info symbol indicates important informationwhere there is no risk to
people or property.
Additional symbols
Table 1
Table 2
1.2 General safety instructions
HNotices for the target group
These installation instructions are intended for plumbing, heating and
electrical contractors. All instructions must be observed. Failure to
comply with instructions may result in material damage and personal
injury, including danger to life.
▶ Read the installation, service and commissioning instructions (heat
source, heating controller, pumps, etc.) before installation. Non-
compliance with safety instructions may result in electric shock,
water leakage, fire or other dangerous situations.
▶ The appliance must be installed, maintained, repaired and removed
in accordance with the installation manual by a qualified installer or
service technician.
A qualified installer or qualified service technician is a person who
has the qualifications and knowledge described in the installation
manual.
▶ This unit is part of a system that contains fluorinated gases as
refrigerant. For specific information on the type of gas and its
amount, please refer to the relevant label on the outdoor unit.
▶ Only qualified personnel can handle, fill, purge and dispose of the
refrigerant.
▶ Observe the safety instructions and warnings.
▶ Follow national and regional regulations, technical regulations and
guidelines.
▶ Record all work carried out.
HIntended use
This product is intended for use in sealed heating systems in residential
buildings.
Anyotheruseisconsideredasnotintended.Liabilitywill notbe assumed
for any resulting damage.
HInstallation, commissioning and service
The product may only be installed, brought into operation and
maintained by trained personnel.
▶ Use only original spare parts.
HRisk of burn from hot surfaces
Exterior pipework of the appliance can reach temperatures above 60 °C,
these should not be touched while the appliance is in operation. Suitable
insulation on the pipework must be installed.
HElectrical work
Electrical work must only be carried out by electrical installation
contractors.
Before starting electrical work:
▶ Isolate all poles of the mains voltage and secure against
reconnection.
▶ Make sure the mains voltage is disconnected.
▶ Before touching live parts: Wait at least 5 minutes to discharge the
capacitors.
▶ Observe the wiring diagrams of other system components as well.
HWhat to do if refrigerant leaks
If refrigerant leaks and touches the skin, it can cause frostbite.
▶ In case of a refrigerant leak, never touch any components of the air to
water system.
▶ Avoid skin or eye contact with refrigerant.
▶ Seek medical attention if you get refrigerant on your skin or in your
eyes.
Symbol Meaning
▶ a step in an action sequence
a reference to a related part in the document
• a list entry
–a list entry (second level)
Symbol Meaning
Warning low burning velocity material. This appliance
uses a flammable refrigerant with low burning velocity
(A2L). If refrigerant leaks and isexposed to an external
ignition source, there is a risk of fire.
Warning strong magnetic field.
Maintenance by a qualified person should be carried
out while following the instructions of the service
manual.
For operation, follow the instructions of the user
manual.

Regulations
Compress 3400i AWS – 6721852066 (2023/01)
4
HHandover to the user
When handing over, instruct the user how to operate the heating system
and inform the user about its operating conditions.
▶ Explain how to operate the heating system and draw the user's
attention to any safety relevant action.
▶ In particular, point out the following:
– Modificationsandrepairs must only be carried out byanapproved
contractor.
– Safe and environmentally compatible operation requires
inspection at least once a year and proper cleaning and
maintenance.
▶ Point out the possible consequences (personal injury, including
danger to life or material damage) of non-existent or improper
inspection, cleaning and maintenance.
▶ Leavethe installation instructions and the operatinginstructionswith
the user for safekeeping.
1.2.1 Refrigerant
HRefrigerant R32
▶ This appliance is filled with refrigerant R32. If refrigerant gas gets
into contact with fire, it may generate a toxic gas or fire.
▶ Do not let any other substance than the specified refrigerant enter
the refrigerant circuit.
▶ Ensure that the refrigerant pipe is connected before running the
compressor.
▶ Be aware that refrigerant may not contain any odour.
▶ Read all safety instructions for handling flammable refrigerants
provided with this appliance in a separate document.
HInstallation, commissioning and service
▶ Do not smoke and makesure that any other possible ignitionsources
are kept way from the working area. Ensure that the installation area
is adequately ventilated.
▶ Do not pierce or burn.
▶ This appliance must be stored in a room without continuously
operating ignition sources (e.g. open flames, operating gas or
operating electric heater).
▶ Prior and during installation, make sure that there are no refrigerant
leaks using an appropriate refrigerant detector that is adequately
sealed and intrinsically safe (i.e. no sparking). Never use potential
sources of ignition to search for refrigerant leaks. A halide torch (or
any other detector using a naked flame) may not be used. If a
refrigerant leak is detected, ventilate the room immediately.
▶ Whenperforming anyhot work,a dry powder orCO2fireextinguisher
should be kept ready.
▶ Wear protective gloves during installation.
▶ Do not use means to accelerate the defrosting process or to clean the
appliance, other than those recommended by the manufacturer.
HMaintenance
▶ When changing electrical components assure that these correspond
with the correct specification. Maintenance and service guidelines
must always be followed.
▶ Before any repair and maintenance procedure, an initial safety check
and component inspection procedures should be performed to
check that:
– Capacitors are discharged.
– All electrical components are switched off and wiring is not
exposed.
– Earth bonding continuity is ensured.
▶ Do not connect any electrical supply to the circuit if a fault that can
compromise safety is detected.
2Regulations
This is an original manual. This manual may not be translatedwithout the
approval of the manufacturer.
Follow the directives and regulations given below:
• Local provisions and regulations of the electricity supplier and
corresponding special rules
• National building regulations
•F-Gas regulation
•EN 50160 (Voltage characteristics of electricity supplied by public
electricity networks)
•EN 12828 (Heating systems in buildings - Design for water-based
heating systems)
•EN 1717 (Protection against pollution of potable water installations
and general requirements of devices to prevent pollution by
backflow)
•EN 378 (Refrigerating systems and heat pumps - Safety and
environmental requirements)
2.1 Water quality
Water quality in the heating system
Heat pumps operate at lower temperatures than other heating systems
which means that the thermal de-airing is not as effective and oxygen
levels are never as low as with a system incorporating an electric/oil/ gas
boiler. This means that the heating system will be more susceptible to
corrosion when exposed to aggressive water.
Preventive actions are required if the heating system require recurrent
filling or where a heating water sample don’t show clear water.
Preventive actions can be to supplement the heating system with a
magnetite filter and a de-airing valve.
Actions when the heating system requires recurrent filling:
▶ Check that the volume of the expansion vessel is sufficient to the
heating system volume.
▶ Replace the expansion vessel.
▶ Check the heating system for leaks.
A system separation with the help of a heat exchanger may be required if
the limits in table 3 can not be achieved.
Do not use any water additives except for a non-toxic pH-enhancer
and keep the water clean.
The limits stated in table 3 are required to ensure the output data and
operation of the heat pump throughout its entire service life.
Table 3 Water quality
Additional water treatment to prevent lime-scale deposits
A poor quality of the heating water promotes the formation of sludge and
lime-scale. This can lead to malfunctions and damage of the heat
exchanger in the heat pump. According to the current guideline VDI
2035 “Prevention of damage in water heating installations” and
depending on the degree of hardness of the filling water, the system
volume and the total output of the system, water treatment may be
required to avoid damage due to the formation of lime-scale.
Water quality
Hardness <3 °dH
Oxygen content <1 mg/l
Carbon dioxide, CO2<1 mg/l
Chloride ions, CL-<250 mg/l
Sulphate, SO4<100 mg/l
Conductivity <350 μS/cm
pH 7,5 – 9

Regulations
5
Compress 3400i AWS – 6721852066 (2023/01)
If the limits for water hardness stated in table 3 are exceeded, the
performance of the heat pump will deteriorate over time. If this
performance degradation can be accepted, the limits in figure 1 are
required to ensure the operation of the heat pump throughout its entire
service life.
Table 4 Table for heat pumps
Fig. 1 Limits for water treatment in heat pump systems
A Use completely de-mineralized fill water above the curve,
conductivity ≤ 10 microsiemens /cm.
B Use untreated tap water below the curve. Fill according to the
drinking water regulation.
HwWater hardness.
V Total water volume: fill volume of the heating system and top-up
volume over the service life of the heat pump.
Ifthe total watervolumeis abovethelimit curve in the diagram (Fig. 1)
suitable measures are required for water treatment.
Suitable measures are:
• Use of fully de-mineralized fill water with a conductivity of ≤ 10
microsiemens / cm.
To prevent oxygen from entering the heating water, the expansion vessel
must be adequately dimensioned.
When installing diffusion open pipes, a system separation with the help
of a heat exchanger is required.
Heat pump
output [kW]
Total alkalinity
/total hardness
of the filling
water [°dh]
Maximum fill and top-up water
volume Vmax [m3]
Q< 50 Requirements
according to
figure 1
Requirements according to
figure 1
0,00
0,20
0,40
0,60
0,80
1,00
1,20
1,40
1,60
1,80
2,00
2,20
2,40
2,60
0 5 10 15
0010036248-002
V [m
3
]
H
W
[°dH]
A
B

Product description
Compress 3400i AWS – 6721852066 (2023/01)
6
3 Product description
3.1 Supplied parts
Fig. 2 Supplied parts
[1] Indoor unit
[2] Documentation
[3] Drill template
[4] Magnetic particle filter with strainer
[5] Jumpers for 1-phase installation
[6] Mounting rail
[7] DHW (domestic hot water) temperature sensor
[8] Bag with connectors for the installation module
[9] Outdoor temperature sensor
[10] Screws (x2) and dowels (x2) for mounting bracket
[11] Screws for drip tray (x4)
[12] Copper pipe
[13] Heating circuit flow temperature sensor
[14] Drip tray
1
2
3
4
5
6
7
001004821-001
8
9
14
11
13
10
12

Product description
7
Compress 3400i AWS – 6721852066 (2023/01)
3.2 Information on the indoor unit
The AWS E indoor units are intended for installation inside the building
and for connection to the outdoor unit.
Possible combinations of indoor unit with different outdoor units:
Table 5 Possible combinations
AWS E is equipped with an integrated electric booster heater.
3.3 Declaration of Conformity
The design and operating characteristics of this product comply with the
British, European and supplementary national requirements.
TheUKCA and CE markingsdeclarethattheproduct
complies with all the applicable British and
European legislation, which is stipulated by
attaching these markings.
You can request the complete text of the Declaration of Conformity from
the UK address indicated in this document.
3.4 Type plate
The type plate of the indoor unit is on the side of the appliance. It
contains information on the part number andserialnumberas wellas the
date of manufacture of the device.
3.5 Functional principle
Thefunctionis based on the demand-actuatedcontrolof thecompressor
output and, if needed, by switching on the integrated electric booster
heater via the indoor unit. The control unit controls the outdoor unit
depending on the set heating curve.
If the outdoor unit is unable to satisfy the heat energy demand of the
house, the indoor unit automatically starts the integrated electric
booster heater which produces the desired temperature in the house
together with the outdoor unit.
The DHW heating is controlled via the TW1 sensor in the DHW cylinder.
During the heat-up phase of the DHW cylinder, the heating mode of the
heating system is temporarily switched off via a 3-way valve. Once the
DHW cylinder is heated up, heating mode is resumed by the outdoor
unit.
Heating and DHW mode when the outdoor unit is deactivated
When the outdoor temperature is below –20 °C (approximately) or
exceeds 45 °C (approximately), the outdoor unit is automatically turned
off and is unable to produce any heat. In this case, the integrated electric
booster heater of the indoor unit adopts the heating and DHW mode.
3.6 Product overview
Fig. 3 Components and pipework connections of the indoor unit with
electric booster heater (views with drip tray)
[1] Automatic air vent valve (VL1)
[2] Electric booster heater
[3] Pressure gauge
[4] Installer module
[5] Reset of the overheating protection
[6] Primary circulation pump (PC0)
[7] Flow to the heating system
[8] Drain of the pressure relief valve and condensates
[9] Return from the heating system
[10] Cable feed for power supply
[11] Cable feed for sensor, CAN-BUS and EMS BUS
[12] Refrigerant out to outdoor unit (liquid)
[13] Refrigerant in from outdoor unit (gas)
AWS E CS3400iAWS
CS3400iAWS 10 E CS3400iAWS 4 OR-S1)
1) A 5/8” to 1/2” adapter is provided with CS3400iAWS 4 OR-S
CS3400iAWS 10 E CS3400iAWS 6 OR-S
CS3400iAWS 10 E CS3400iAWS 8 OR-S
CS3400iAWS 10 E CS3400iAWS 10 OR-S
4
5
6
1
2
3
7
13 12
11
8910
001004822-001

Preparing for installation
Compress 3400i AWS – 6721852066 (2023/01)
8
3.7 Product dimensions and minimum clearances
Mount the indoor unit high enough so that the control unit is easy to use.
In addition, take into account pipes and connections under the indoor
unit.
Fig. 4 Minimum distance (mm)
[A] It is recommended to ensure a minimum volume of 1 m³ underneath
the indoor unit. If this is not possible, ensure that the room is not
air-tight by allowing an air vent passage at a height lower than the
bottom of the indoor unit.
Fig. 5 Dimensions and connections (view without drip tray)
3.8 Connection dimensions
Table 6 Pipe dimensions for CS3400iAWS 10 E
4Preparingforinstallation
CAUTION
Risk of fire or explosion!
All possible ignition sources must be kept away from the installation site
as it may lead to fire or explosion.
▶ This appliance must be stored in a room without continuously
operating ignition sources (e.g. open flames, cigarette smoking, an
operating gas or operating electric heater).
NOTICE
Risk of damaging the product!
The indoor unit must not be installed in areas where it isexposed to water
splashes.
▶ Do not install the indoor unit in bathrooms or exterior areas.
WARNING
Strong magnet
Can be harmful to pacemaker wearers.
▶ Do not clean the filter or check the magnetite indicator if you are
pacemaker wearer.
The drain pipe of the pressure relief valve in the indoor unit must be
installed so that it is protected against frost and the drain pipe must be
routed to the drain.
▶ Run the connector pipes for the heating system and cold/domestic
hot water in the building up to the installation location of the indoor
unit.
50 50
800
550
0010035680-001
A
Pipe Connections
Heating system flow 1” male thread
Heating system return 1” female thread
Drain/discharge ø 22
Refrigerant pipe to/from outdoor
unit
1/4” - 5/8”1)
1) A 5/8” to 1/2” adapter is provided for connection with CS3400iAWS 4 OR-S

Installation
9
Compress 3400i AWS – 6721852066 (2023/01)
4.1 Considerations for assembling the indoor unit
• Mount the indoor unit at a suitable location within the house. Use a
spirit level to ensure that the appliance is in the correct position.
• Make sure that there are no operating ignition sources in the room
where the indoor unit is installed.
• Pipe work between the outdoor and indoor units must be as short as
possible. Use insulated pipes.
• Check that all pipe connections are intact and have not come loose
during transportation.
• Ensure all pipes and connections are protected against physical
damage. Mechanical connections to the indoor unit must be
accessible for maintenance purposes.
• Follow the instructions of the outdoor unit installation manual.
• Water discharged from the pressure relief valve should be routed
away from the indoor unit to visibly terminate in a frost-free outlet.
• The installation location of the indoor unit must have a drain.
• The low voltage cables must be routed with a minimum clearance of
100 mm from live 230V cables.
4.2 Heating system minimum volume and flow
A sufficient amount of energy stored in the system is required to avoid
multiple start/stop cycles, incomplete defrosting or unnecessary
alarms.Energyis storedin the heating system watervolume, as well as in
the system components (radiators and underfloor heating).
For the defrost operation of the outdoor unit, a minimum volume and
flow must be ensured and permanently available.
The minimum volume can be provided by the open circuits (the
necessary zone valves/thermostatsmustbe alwaysfullyopen)and/orby
a buffer tank. For an optimal and most efficient defrost operation a
recommended volume is stated.
The minimum flow must be ensured within the minimum volume
available. If the minimum flow is not met, additional measures are
needed, e.g. differential bypass valve or parallel buffer. Note that if an
hydraulic separator is present it requires an additional heating circuit
pump.
In certain circumstances depending on the available energy stored in the
system, the auxiliary heater may be used to ensure the complete defrost.
Table 7 Minimum volume and flow for outdoor unit CS3400iAWS 4 OR-
S
Table 8 Minimum volume and flow for outdoor unit CS3400iAWS 6-10
OR-S
5 Installation
NOTICE
Residue in the pipework can damage the system.
Residue and particles in the heating system impair the flow rate and lead
to faults.
▶ Before connecting the indoor unit, flush the pipe system to remove
any foreign bodies.
CAUTION
Risk of injury!
During transport and installation there isa risk of crushing injury. During
maintenance, internal parts of the appliance may become hot.
▶ The installer is obliged to wear gloves during transport, installation
and maintenance.
The indoor unit is part of a heating system. Faults in the indoor unit can
occur from poor water quality in the radiators or pipework of the
underfloor heating system, or when the oxygen content in the system is
persistently high.
Oxygen causes corrosion products in the form of magnetite and
sediment.
Magnetite is an abrasive material which affects pumps, valves and
components with turbulent flow characteristics, e.g. in the condenser.
If heating systems have to be regularly refilled or if hot water samples
from these systems are cloudy, corresponding measures such as
retrofitting magnetite separators and air vents are required.
▶ Ensure the insides of the pipes are clean and do not contain any
harmful contaminants such as sulphuric compounds, oxidants,
debris and dust.
– Never store refrigerant pipes outdoors.
– Only remove seals from the pipe ends when you are ready to
connect them.
– Utmost care must be taken when routing refrigerant lines.
– Only shorten refrigerant lines using pipe cutters and seal the ends
afterwards to prevent the ingress of dirt and moisture.
Dust, foreign bodies and moisture inside the refrigerant lines can be
detrimental to oil quality or can result in compressor failure.
▶ After cutting, immediately reseal reusable lengths of refrigerant
pipes.
▶ Purge the refrigerant pipes with nitrogen.
NOTICE
Danger of malfunction due to contaminants in pipework!
Solids, metal/plastic filings, flux and thread tape residue and similar
material can get stuck in pumps, valves and heat exchangers.
▶ Keep foreign bodies from entering the pipework.
▶ Do not leave pipe parts and connections directly on the ground.
▶ When deburring, make sure that no residue remains in the pipe.
WARNING
Risk of personal injury and damage to property
Using the incorrect sensors may lead to personal injury such as scalding
as well as damage to property due to an excessively high or low
Outdoor Unit CS3400iAWS 4 OR-S
Minimum Recommended
Underfloor/fan coils 13l 35l
Radiators 4l 13l
Minimum flow 15l/min
Outdoor Unit CS3400iAWS 6-10 OR-S
Minimum Recommended
Underfloor/fan coils 27l 40l
Radiators 10l 15l
Minimum flow 15l/min

Installation
Compress 3400i AWS – 6721852066 (2023/01)
10
temperature. Comfort can also be adversely affected by using the
incorrect sensors.
▶ Make sure that you use the correct sensor with the appropriate
characteristics when exchanging a sensor (Chapter 11.6). Using
sensors with other characteristics will lead to problems because the
systemwillbecontrolledwith referencetotheincorrecttemperature.
5.1 Transport and storage
The indoor unit must always be transported and stored in an upright
position. If needed, it may be leaned temporarily.
The indoor unit may not be stored or transported at temperatures below
– 10 °C.
5.2 Insulation
NOTICE
Material damage from frost!
In case of a power failure, the water in the pipes may freeze.
▶ All heat-conducting pipework must be provided withsuitable thermal
insulation according to applicable regulations.
If it is envisaged that the cooling operation will be carried out below the
dew point, all connections and pipes must be appropriately insulated in
accordance with the valid regulations (minimum insulation thickness 13
mm).
5.3 Checklist
Each installation is different. The following checklist contains a general
description of the recommended installation steps.
As a recommendation, the refrigerant line should be connected before
the hydraulic connections.
The particle filter is installed horizontally in the heating system return
upstream of the inlet of the indoor unit. Note the direction of flow of the
filter.
1. Remove the front cover of the indoor unit.
2. Assemble the drip tray.
3. Mount the leakage copper pipe and assure the proper pipework from
the indoor unit.
4. Connect the refrigerant pipes from the outdoor unit to the indoor
unit.
5. Connect the indoor unit to the heating system.
6. Connect, fill and vent the DHW cylinder (if installed).
7. Before starting operation, fill the heating system.
8. Vent the heating system.
9. Install the outside temperature sensor and, if necessary, the room
controller.
10.Connect the CAN-BUS cable to the outdoor and indoor unit.
11.Install accessories (heating circuit module, etc.).
12.If required, connect the EMS BUS cable to the accessory.
13.Establish the electrical connection of the system.
14.Put the heating system into operation. Use the control unit to make
the necessary settings (instructions for control unit).
15.Check that all sensors display the appropriate values.
16.Check and clean the particle filter.
17.Check the operation of the heating system after starting up (
instructions for control unit).
5.4 Removing the front cover of the indoor unit
Fig. 6 Remove front cover
To remove the front cover of the indoor unit, follow these steps:
1. Unscrew the lower part of the front cover.
2. Hold the lower part of the front cover on the holders.
3. Unscrew the upper part of the front cover.
4. Remove the upper part of the front cover.
5. Remove the intermediate connector of the control device and
complete the removal of the lower part of the front cover.
4
11
5
33
0010035653-002