Flexit Nordic S4 User manual

Nordic S4
USER MANUAL
Air handling unit
ART.NO. 800130, 800131, 800132, 800133
115546EN-01
2018-02
Flexit
GO

2
NORDIC S4

3
NORDIC S4
Contents
1. Automatic control.........................................................................................................6
2. Functional description of balanced ventilation ........................................................7
2.1. Fans (M1, M2) ................................................................................................................. 7
2.2. Filters (FI1, FI2)................................................................................................................ 7
2.3. Rotor (HR-R) .................................................................................................................... 7
2.4. Heating element (EB1)..................................................................................................7
2.5. Temperature sensors (B1, B4)....................................................................................7
2.6. For use with dampers................................................................................................... 7
2.6.1. Damper (DA1) .....................................................................................................7
2.6.2. Damper (DA2) .....................................................................................................7
3. Operating the door ......................................................................................................8
3.1. If a door needs to be removed ..................................................................................9
4. Cleaning and maintenance ...................................................................................... 10
4.1. Cleaning the fans .........................................................................................................10
 &KDQJLQJWKHȴOWHUV .....................................................................................................11
4.3. Changing the brush strips .........................................................................................13
4.4. Cleaning the rotor .......................................................................................................15
4.5. External cleaning..........................................................................................................15
5. Maintenance table .................................................................................................... 16
6. Troubleshooting ........................................................................................................ 17
7. CE Declaration of Conformity .................................................................................. 18

4
NORDIC S4
DANGER! DO NOT
TOUCH
Symbols used
These products bear a number of symbols used for
labelling the actual product and in installation and user
documentation.
Extract air
Outdoor air
Supply air
Exhaust air
DANGER:
ELECTRICITY
EXAMPLE OF NIPPLE LOCATIONS
(shown as a right model)
!
DANGER! When a text box is this colour,
it means that a life-threatening or
serious personal injury may be the
consequence of not following the
instructions.
CAUTION! When a text box is this
colour, it means that material damage
may be the consequence of not
following the instructions.
!
EXAMPLE OF NIPPLE LOCATIONS
(shown as left model)
FRONT FRONT
NOTICE! When a text box is this colour,
it means that a poor utilisation ratio or
product operating issues may be the
consequence of not following the
instructions.
!
INFO! When a text box is this colour,
LWbPHDQVWKDWLWFRQWDLQVLPSRUWDQW
information.
Extract air
from kitchen

5
NORDIC S4
!SAFETY
INSTRUCTIONS
• 7RDYRLGWKHULVNRIȴUHHOHFWULF
shock or injury, read all the safety
instructions and warning texts
before using the unit.
• All electrical connections must be
FDUULHGRXWE\TXDOLȴHGHOHFWULFLDQV
• If the power lead is damaged,
it must be replaced by the
manufacturer, the manufacturer’s
VHUYLFHDJHQWRUDVLPLODUO\TXDOLȴHG
person.
• The unit must not be used to
H[WUDFWFRPEXVWLEOHRUȵDPPDEOH
gases.
• It is the installer’s responsibility to
carry out a full safety and function
assessment of the appliance.
• %HIRUHRSHQLQJWKHGRRUVZLWFKR΍
the heat, let the fans continue for
bPLQXWHVWRUHPRYHKRWDLUXQSOXJ
the unit and wait 2 minutes before
opening the doors, as the unit
contains elements that must not
EHbWRXFKHGZKHQKRW
• This appliance may be used by
children of 8 years or above or
by persons with reduced sensory
capacity or reduced physical or
mental capacity, or by persons
lacking experience or knowledge,
provided they have received
instruction in the safe use of the
appliance or are supervised to
ensure safe use and providing they
are aware of the risks.
• The product is not suitable for use
by children. Children must not be
allowed to play with the appliance.
Children must not carry out
cleaning or maintenance without
supervision.
!
• This unit is only designed for
ventilation air in homes and
commercial buildings.
• To maintain a good indoor climate,
comply with regulations and avoid
condensation damage, the unit
must never be stopped apart from
during service/maintenance or in
connection with an accident.
• The unit must not be operated
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• All plumbing work must be carried
out by an authorised plumber.
• The location of the water battery
must be approved by a plumber
owing to the risk of water leaks.
!
• Tumble dryers must not be
connected to the unit.
• The room must have a separate,
adequate air supply when products
such as gas cookers, gas heaters,
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RLOȴUHGERLOHUVHWFDUHXVHG
!

6
NORDIC S4
1. Automatic control
These instructions only describe how to use the air
handling unit and do not go into the details of installing/
using automatic control.
Alternative user interfaces:
• Flexit GO app (standard)
To control the air handling unit via a smartphone/
tablet, download the app from Google Play Store or
WKH$SSb6WRUH
See manual (116909) for automatic control system.
• CI 70 control panel
See manual (116081).
For more information on the automatic control system,
VHHZZZȵH[LWFRP

7
NORDIC S4
2. Functional description of balanced ventilation
2.6. FOR USE WITH DAMPERS
2.6.1. Damper (DA1)
There is a closing air damper in the exhaust air duct to
prevent cold draughts.
2.6.2. Damper (DA2)
There is a closing air damper in the outdoor air duct to
prevent cold draughts.
If a water battery is used, the damper prevents frost
damage to the battery.
!
Adjustment must always be carried
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LQVWDOODWLRQLVXVHGIRUWKHȴUVWWLPH
B1
M2
M1
EB1
F10
F20
M4
HR-R
FI2 FI1
B4
K
DA1DA2
B3 B6
2.1. FANS (M1, M2)
The fans ensure that air enters and leaves the building.
They can be individually adjusted for optimal operation.
7KHXQLWFDQEHUHJXODWHGDWGL΍HUHQWVSHHGVYLDWKH
control panel: Home, Away, High.
2.2. FILTERS (FI1, FI2)
)LOWHUVZLWKDKLJKȴOWHUJUDGHDUHXVHGDVVWDQGDUGIRU
both supply air and extract air so that the air which
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WKHXQLWVWD\VFOHDQDQGFDQPDLQWDLQWKHUPDOHɝFLHQF\
DQGDLUȵRZ
2.3. ROTOR (HR-R)
The air passes through the rotary wheel-type heat
exchanger (recovery system). The rotor functions as
a heat magazine. The heat from the extract air heats
up one part of the rotor. When the heated part comes
over to the supply air side, the heat is transferred to
WKHbVXSSO\DLU
2.4. HEATING ELEMENT (EB1)
If the energy recovered from the extract air is
LQVXɝFLHQWbWRPDLQWDLQWKHVHWVXSSO\DLUWHPSHUDWXUH
an electric heating element will help raise the
WHPSHUDWXUH7KHbKHDWLQJHOHPHQWLVSURWHFWHGDJDLQVW
overheating by the thermostat (F20) which cuts out
at high temperature. For extra safety, the thermostat
(F10) cuts out at critical temperatures. Thermostat F10
needs to be reset manually by pressing the reset button.
6HHbReset button on page 17.
2.5. TEMPERATURE SENSORS (B1, B4)
As standard, the unit has four temperature sensors.
Supply air sensor (B1) registers the temperature after
the heating battery. The extract air sensor (B3) registers
the temperature of the extract air. The outdoor air
sensor (B4) registers the temperature of the outdoor
DLU7KHH[KDXVWDLUȴOWHU%UHJLVWHUVWKHWHPSHUDWXUH
RIbWKHH[KDXVWDLU

8
NORDIC S4
3. Operating the door
1. Turn the screw in the lock 90°.
2. Flip up the lock handle
3. The lock handle needs to be lifted right up to release.
Therefore press the lock handle right up while
opening the door.
1 2 3
90°

9
NORDIC S4
3.1. IF A DOOR NEEDS TO BE REMOVED
7KHGRRUFDQEHOLIWHGR΍ZKHQLWLVRSHQEHWZHHQ
|bDQG|VHH)LJ
If there is limited space in front of the unit, the lock
screw on the underside of the unit can be unscrewed
(see Fig. 2) and the door pushed out sideways (see Fig. 3).
In this case it can be open less than 40º.
!
The door weighs 6.5kg – take care
when removing it.
40-105°
Fig. 1
Fig. 2 Fig. 3

10
NORDIC S4
grease solvent on a cloth (e.g. methylated spirits) and
compressed air if possible.
NB: Take care that the motor is not exposed to water.
To take out the fans:
1. Unplug.
2. Remove the cover, if there is one, on the fan
compartment.
3. Undo the screws on the electric cover and take the
FRYHUR΍
4. Disconnect the electric quick-release contact by
pressing in at the same time as pulling the contact
apart.
5. Pull the cable bushings for the fans out of the grooves
so that the cables with quick-release contacts come too.
6. Remove the fans by pulling on the holes.
4. Cleaning and maintenance
!
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the heat, let the fans continue for
bPLQXWHVWRUHPRYHKRWDLUXQSOXJ
the unit and wait 2 minutes before
opening the doors.
4.1. CLEANING THE FANS
The fans must be inspected at least once a year
and cleaned as needed. Clean the fan blades with a
21
3
6
x2
4
5

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NORDIC S4
4.2. CHANGING THE FILTERS
7KHȴOWHUVKDYHDOLPLWHGOLIHDQGWRSUHVHUYHDKHDOWK\
indoor air quality it is important to change them when
they are dirty.
+RZRIWHQWKHȴOWHUVQHHGWREHFKDQJHGGHSHQGVRQ
the degree of contamination of the air where they are
LQVWDOOHGΖQJHQHUDOWKHȴOWHUVQHHGWREHFKDQJHG
at least once a year, preferably in the autumn (after
the pollen season). In areas with a lot of dust and
FRQWDPLQDWLRQWKHȴOWHUVVKRXOGEHFKDQJHGLQWKH
spring and autumn.
'LUW\ȴOWHUVFDQDPRQJRWKHUWKLQJVOHDGWR
• Reduced performance of the unit
• The unit becoming dirty
• Humidity damage
• Reduced indoor air quality
$ȴOWHUVXEVFULSWLRQLVUHFRPPHQGHGWRHQVXUHIXOO
EHQHȴWIURPWKHV\VWHP
7RWDNHRXWWKHȴOWHUV
1. Unplug.
2. 5HPRYHWKHFRYHULIWKHUHLVRQHRQWKHȴOWHU
compartment.
3. *ULSWKHKDQGOHDQGSXOOWKHȴOWHURXW
4. ΖQVHUWDQHZȴOWHU
&KDQJHERWKȴOWHUVVXSSO\DLUDQG
exhaust air) at the same time.
21
3

12
NORDIC S4
0DNHVXUHWKDWWKHȴOWHULVQRW
GDPDJHGGXULQJȴWWLQJ+ROGWKH
ȴOWHUȇVRXWHUHGJHZKHQSXVKLQJLWLQ
$GDPDJHGȴOWHUUHGXFHVWKHXQLWȇV
power and the air’s purity.
&KHFNWKDWWKHȴOWHUȇVVHDOLVLQWDFW
EHIRUHLQVHUWLQJWKHȴOWHU7KHQSXVK
WKHȴOWHUSURSHUO\LQWRSODFHWR
prevent air leakage.
:KHQFKDQJLQJWKHȴOWHUFKHFNWKDWWKHZKROHXQLWLV
working normally. Use the following checklist:
• Check that the rotor rotates. Turn the rotor in the
direction of rotation as shown on the rotor cassette.
• If necessary, clean the rotor, see 4.4. Cleaning the
rotor on page 15.
• 7KHXQLWKDVȴOWHUVIRUERWKRXWGRRUDLUDQGH[WUDFWDLU
• Check that the fans are clean, see 4.1. Cleaning the
fans on page 10.

13
NORDIC S4
4.3. CHANGING THE BRUSH STRIPS
The brush strips become worn over time. If they do
not lie tightly against the rotary exchanger, it may be
necessary to change them.
Alternatively, they may be moved closer to the rotor,
DVbWKHSURȴOHWKH\DUHPRXQWHGLQKDVWZRJURRYHV
Proceed as follows:
1. Undo the screws on the electric cover and take the
FRYHUR΍
1
4
4. Pull the rotor module out about 2-3 cm.
5. Pull the cable bushing over the middle of the rotor
out of the groove so that the cable with the quick-
release contact comes too.
2. Pull the cable lug out to disconnect the earth on the
circuit board.
3. Also disconnect the rotor’s quick-release contact
from the circuit board.
6. Pull the cable bushing at the side of the rotor out
DVbZHOO
2
3
5
5
6

14
NORDIC S4
9
1110
LEVEL 1
LEVEL 2
7. Pull the rotor module right out and position it with
the brush strips facing up.
8. 8QGRWKHVFUHZLQWKHFHQWUHRIWKHVWHHOSURȴOH
5HOHDVHWKHWRSRIWKHVHDOLQJVWULSVRWKDWWKHSURȴOH
can be removed.
8
7
9. )OLSR΍WKHEUXVKVWULSSURȴOHVZLWKDVFUHZGULYHUHWF
There are 4 brush strips on the rotor, 2 on each side.
Use a broad screwdriver, so you can get a good
FRQWDFWZLWKRXWEHQGLQJWKHSURȴOH6WDUWDWRQHHQG
and continue to the other. Lift it carefully, bit by bit.
10. Pull the brush strips out of the groove.
11. Move the brush strips down to level 2, or replace
them with new ones if they are completely worn out.

15
NORDIC S4
4.4. CLEANING THE ROTOR
$KLJKLPSHUPHDELOLW\ȴOWHULVLQVWDOOHGLQWKHXQLW
ΖWbLVbQRWWKHUHIRUHXVXDOO\QHFHVVDU\WRFOHDQWKHURWRU
ΖIbIRUbDQ\UHDVRQLWVKRXOGVWLOOEHQHFHVVDU\GXVWFDQ
EHbUHPRYHGZLWKDVRIWEUXVK
Further cleaning is possible by removing the rotor,
spraying it with a grease solvent and then blowing it
clean from the opposite side. Distance approximately
bPPDQGPD[SUHVVXUHEDU
Ensure that the motor is not exposed to water during
cleaning. Ensure that all seals around the rotor are intact
and tight. Ensure that there is no damage to the rotor
belt, and that the rotor rotates freely.
4.5. EXTERNAL CLEANING
Many kitchen surface cleaners contain chemicals
that may damage the product’s plastic components.
Therefore use a soft cloth moistened with warm water
and a neutral detergent to clean the outside of the
product.
Do not use sharp objects, powerful
cleaners or scouring powder, as such
products can damage the surfaces.
Cleaners containing ammonia or
citrus must not be used. Products
that give stainless steel an anti-
ȴQJHUSULQWFRDWLQJPXVWQRWEH
XVHGbHLWKHU
12
13
12. 3UHVVWKHEUXVKVWULSSURȴOHEDFNLQWRSODFH
13. 7KHQVFUHZWKHVWHHOSURȴOHEDFNRQ3UHVVWKH
sealing strip towards the short end of the steel
SURȴOHWRIRUPDVHDO7KHSURȴOHDOVRKDVDVHDOLQJ
strip along one side. NB: It is important to screw the
SURȴOHRQWKHULJKWZD\VRWKDWWKHVHDOVLWVWLJKWO\
against the partition inside the unit.
Push the rotor back in.

16
NORDIC S4
5. Maintenance table
Component Action Interval
Filter Filters must be changed at least once a year. It is best to change them twice a year, before and after
WKHSROOHQVHDVRQ&KHFNWKDWWKHȴOWHUVHDOLVFRPSOHWHO\WLJKW
6-12 months
Fans The fan in a unit connected to a kitchen hood should be inspected once a year.
)RUDIDQLQDXQLWWKDWLVQRWFRQQHFWHGWRDNLWFKHQKRRGLQVSHFWLRQHYHU\\HDUVLVVXɝFLHQW
The fans should be cleaned as needed.
12 months
3 years
Recovery
system
Check that the surfaces are clean. Check that the sealing strips face in towards the rotary wheel-type
heat exchanger.
Check that the rotor belt is intact and not too slack.
3 years
Kitchen fan For a unit with exhaust from a kitchen fan connected:
:DVKWKHJUHDVHȴOWHU&KHFNWKDWWKHGDPSHULVFOHDQDQGFORVHVIXOO\
2 weeks
Seals &KHFNWKDWWKHVHDOVRQWKHGRRUXQGHUWKHȴOWHUVRQWKHIDQPRGXOHVDQGRQWKHURWRUPRGXOH
DUHbLQWDFW
12 months
Valves The supply air and extract air valves (for the bathroom, bedroom, laundry room, etc.) must be
cleaned at least once a year.
12 months
Air intake Check that no leaves or other items have caught in the grille.
The air intake can freeze up in winter and should be checked regularly (daily if necessary).
If necessary, it must be scraped clean so that the air can pass through.
12 months
Roof cowl If the unit has a roof cowl, this must be checked for leaves and the like. Also check that the drain
slots are open.
12 months
Ducts Check that the ducts are clean. 10 years
Brush strips Check that the brush strips are intact and sit tightly against the rotor. If they are worn, they can be
PRYHGWRWKHQH[WJURRYHLQWKHSURȴOHVRWKDWWKH\DUHFORVHUWRWKHURWRU
3 years
Inside unit A combination of a very low outside temperature and damp extract air can lead to the formation of
ice. Normally this will not be a problem – when normal operating conditions return the ice crystals
will be converted to steam and removed from the unit via the exhaust air. In the case of extreme
cold over extended periods the unit should be checked for ice.

17
NORDIC S4
6. Troubleshooting
Type of fault Remedial action
Cold draughts Check which supply temperature has been selected. See control panel.
Check that the rotor rotates. The rotor belt can be tightened by moving the rotor motor bracket*
Check that heating comes on.
1HZH[WUDFWȴOWHUQHHGHG
Fans not working Check that power is connected to the unit.
Check that the overheating thermostat has not cut out.
Restart the overheating thermostat by pressing the button**. It also has to be reset in the app or on the control
panel.
/RZDLUȵRZUDWH Check what speed the unit is set to.
&KHFNWKDWWKHȴOWHUVDUHWLJKW
Check the intake grille.
Reset button
The thermostat (F10) has to be reset manually by
pressing the reset button.
(left model)
**
To tighten the rotor belt, move the rotor motor bracket to the
free holes in the rotor box.
*

18
NORDIC S4
7. CE Declaration of Conformity
7KLVGHFODUDWLRQFRQȴUPVWKDWWKHSURGXFWVPHHWWKH
requirements in the following Council Directives and
standards:
2004/108/EC Electromagnetic compatibility (EMC)
2006/95/EC Low-voltage Directive (LVD)
1253/2014 Ecodesign Directive
1254/2014 Energy Labelling Directive
Our products have been tested in accordance with parts of:
2006/42/EC Machine Directive (Safety)
Producer: FLEXIT AS, Televeien 15, 1870 Ørje, Norway
Type: Nordic S4 Air handling unit
Complies with the following standards:
Safety standard EN 60335-1:2012 + A11
EMF standard: EN 62233: 2008
EMC standard: EN 55014-1.2006 + A1 + A2
EN 61000-3-2: 2006 + A1 + A2
EN 61000-3-3: 2013
EN 55014-2:1997 + A1 + A2
The product is CE-marked: 2016
FLEXIT AS 2017
Knut Skogstad
CEO

19
NORDIC S4

FLEXIT AS, Televeien 15, 1870 Ørje, Norway
www.flexit.no