Flexit Nordic S4 User manual

Nordic S4
USER MANUAL
Air handling unit
ART.NO. 800130, 800131, 800132, 800133
115546EN-06
2023-08
Flexit
GO

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NORDIC S4

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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 (EB) ....................................................................................................7
2.5. Temperature sensors (B1, B3/H1, B4, B6)............................................................... 7
2.6. For use with dampers...................................................................................................7
2.6.1. Damper (DA1) .....................................................................................................7
2.6.2. Damper (DA2) .....................................................................................................7
2.7. Kitchen fan....................................................................................................................... 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
4.2. Changingthelters .....................................................................................................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. Complaints ................................................................................................................. 18
8. Waste handling.......................................................................................................... 18

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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
Extract air
from kitchen
INFO! When a text box is this
colour, itmeans that it contains
important information.
i
CAUTION! When a text box is this
colour, it means that material
damage may be the consequence
of not following the instructions.
!
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.
!
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.
EXAMPLE OF NIPPLE LOCATIONS
(shown as a right model)
EXAMPLE OF NIPPLE LOCATIONS
(shown as left model)
FRONTFRONT

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NORDIC S4
!
SAFETY
INSTRUCTIONS
!
• 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, fireplaces, wood-
burning stoves, oil-fired boilers,
etc., are used.
• 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
without the filters being in place.
• 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.
!
• To avoid the risk of fire, electric
shock or injury, read all the safety
instructions and warning texts
before using the unit.
• All electrical connections must
be carried out by qualified
electricians.
• If the power lead is damaged, it
must be replaced by the
manufacturer, the manufacturer’s
service agent or a similarly
qualified person.
• The unit must not be used to
extract combustible or flammable
gases.
• It is the installer’s responsibility to
carry out a full safety and function
assessment of the appliance.
• Before opening the door: switch
off the heat, let the fans continue
for 3minutes to remove hot
air, unplug the unit and wait
2 minutes before opening the
doors, as the unit contains
elements that must not be
touched when hot.
• 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.
!
• That precautions must be taken
to avoid the back-flow of gases
into the room from the open
flue of gas or other fuel-burning
appliances (for duct and partition
fans).

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NORDIC S4
1. Automatic control
These instructions only describe how to use the
ventilation unit and do not go into the details of
installing/using automatic control.
There are also automatic functions on the product
which, if necessary, can override the selected operating
mode of the product.
For more information on the automatic control system,
seewww.exit.com.
User manual
Flexit GO
For installer, see startup guide (116628).
For end user, see startup guide (116908).
Flexit GO-app NordicPanel
control panel
(accessory)
Google Play App Store
• Flexit GO app
To control the ventilation unit via a smartphone/tablet,
download the app from Google Play or the App Store.
See startup guide for installer (116628) and startup
guide for end user (116908).
• NordicPanel control panel (accessory)
See manual (120018).
Installation instructions
NordicPanel
NordicPanel can be fitted to Nordic
air handling units manufactured
after 1 October 2022.
i
Just check for a cable on top of the unit marked
“NordicPanel”.
You can also install NordicPanel on older units
manufactured between May 2019 and September 2022.
All you need is a cable kit. Contact your nearest dealer
for more information.

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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
out by qualified staff before the
installation is used for the first time.
2.7. KITCHEN FAN
To reduce the risk of negative pressure in the home,
when using a kitchen fan with an air volume above
approx. 200m3/h is compensated for this with, for
example, an outdoor air valve in the wall.
B1
M2
M1
EB
F10
F20
M4
HR-R
FI2 FI1
B4
K
DA1
DA2
B3/H1 B6
2.1. FANS (M1, M2)
The fans ensure that air enters and leaves the building.
They can be individually adjusted for optimal operation.
Theunitcanberegulatedat3dierentspeedsviathe
control panel: Home, Away, High.
2.2. FILTERS (FI1, FI2)
Filterswithahighltergradeareusedasstandardfor
both supply air and extract air so that the air which
entersthebuildingisclean.Theltersalsoensurethat
theunitstayscleanandcanmaintainthermaleciency
andairow.
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
thesupplyair.
2.4. HEATING ELEMENT (EB)
If the energy recovered from the extract air is
insucienttomaintainthesetsupplyairtemperature,
an electric heating element will help raise the
temperature.Theheatingelementisprotectedagainst
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.
Seechap. Reset button on page 17.
2.5. TEMPERATURE SENSORS (B1, B3/H1,
B4, B6)
As standard, the unit has four temperature sensors.
Thesupplyairsensor(B1)registersthetemperature
after the heating battery. The extract air sensor (B3/
H1) registers the temperature and relative humidity of
the extract air. The outdoor air sensor (B4) registers the
temperature of the outdoor air. The exhaust air sensor
(B6) registers the temperature of the exhaust air.

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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°

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NORDIC S4
3.1. IF A DOOR NEEDS TO BE REMOVED
Thedoorcanbeliftedowhenitisopenbetween
40ºand105º(seeFig.1).
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 6,5 kg – take care
when removing it.
40-105°
Fig. 1
Fig. 2 Fig. 3

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NORDIC S4
To avoid accidental swapping of the
fans, it is recommended that only
one fan is switched off at a time.
i
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
covero.
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
!
Before opening the door: Switch
off the heat, let the fans continue
for 3minutes to remove hot air,
unplug the unit and wait 2 minutes
before opening the doors.
4.1. CLEANING THE FANS
Cleanthefansatthetimeintervalsspeciedinchap.5.
Maintenance table on page 16. Clean the fan blades
with a 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.
2
1
3
6
x2
4
5

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NORDIC S4
4.2. CHANGING THE FILTERS
The lters have a limited life, and to preserve a healthy
indoor air quality it is important to change them when
they are dirty.
Howoftentheltersneedtobechangeddependson
the degree of contamination of the air where they are
installed.Ingeneral,theltersneedtobechanged
at least once a year, preferably in the autumn (after
the pollen season). In areas with a lot of dust and
contamination,theltersshouldbechangedinthe
spring and autumn.
Dirtylterscan,amongotherthings,leadto:
• Reduced performance of the unit
• The unit becoming dirty
• Humidity damage
• Reduced indoor air quality
Altersubscriptionisrecommendedtoensurefull
benetfromthesystem.
!
It is important to use a Flexit
original filter.
If you use a lter other than a Flexit original lter,
the ventilation unit may not work as intended. Flexit
therefore accepts no liability for any operating faults.
!
Change both filters (supply air and
exhaust air) at the same time.
!
Make sure that the filter is not
damaged during fitting. A damaged
filter reduces the unit’s power and
air purity.
!
Check that the filter’s seal is intact
before inserting the filter.
Then push the filter properly into
place to prevent air leakage.
!
CAUTION! The unit must not be
used without a filter.
!
Clogged filters may reduce heat
recovery in the ventilation unit and
cause humidity damage.
Please note that a complaint may be rejected if you use
alterotherthananoriginalFlexitlter.
Fortherightlter,see‘Accessories’underyouruniton
Flexit’swebsite.

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NORDIC S4
Totakeoutthelters:
1. Unplug.
2. Removethecover,ifthereisone,onthelter
compartment.
3. Gripthehandleandpullthelterout.
4. Insertanewlter.
21
3

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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,
astheproletheyaremountedinhastwogrooves.
Proceed as follows:
1. Undo the screws on the electric cover and take the
covero.
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
aswell.
5
5
6
2
3

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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. Undothescrewinthecentreofthesteelprole.
Releasethetopofthesealingstripsothattheprole
can be removed.
8
7
9. Flipothebrushstripproleswithascrewdriver,etc.
There are 4 brush strips on the rotor, 2 on each side.
Use a broad screwdriver, so you can get a good
contactwithoutbendingtheprole.Startatoneend
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.

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NORDIC S4
4.4. CLEANING THE ROTOR
Ahigh-impermeabilitylterisinstalledintheunit.
Itisnotthereforeusuallynecessarytocleantherotor.
If,foranyreason,itshouldstillbenecessary,dustcan
beremovedwithasoftbrush.
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
60mmandmax.pressure8bar.
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.
i
Cleaners containing ammonia or
citrus must not be used. Products
that give stainless steel an anti-
fingerprint coating must not be
usedeither.
i
12
13
12. Pressthebrushstripprolebackintoplace.
13. Thenscrewthesteelprolebackon.Pressthe
sealing strip towards the short end of the steel
proletoformaseal.Theprolealsohasasealing
strip along one side. NB: It is important to screw the
proleontherightwaysothatthesealsitstightly
against the partition inside the unit.
Push the rotor back in.

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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
thepollenseason.Checkthattheltersealiscompletelytight.
Asstandard,amaintenanceremindertochangethelterwillappearevery6months.
6-12 months
Fans The fan in a unit connected to a kitchen hood should be inspected once a year.
Forafaninaunitthatisnotconnectedtoakitchenhood,inspectionevery3yearsissucient.
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:
Washthegreaselter.Checkthatthedamperiscleanandclosesfully.
2 weeks
Seals Checkthatthesealsonthedoor,underthelters,onthefanmodulesandontherotormodule
areintact.
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. Clean if necessary. 6 years
Brush strips Check that the brush strips are intact and sit tightly against the rotor. If they are worn, they can be
movedtothenextgrooveintheprolesothattheyareclosertotherotor.
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.

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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.
Check that heating comes on.
Newextractlterneeded.
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.
Lowairowrate Check what speed the unit is set to.
Checkthattheltersaretight.
Check the intake grille.
Reset button
The thermostat (F10) has to be reset manually by
pressing the reset button.
(left model)
*

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NORDIC S4
7. Complaints
Warranty claims will only be valid
if the instructions in the manuals
have been followed.
i
Complaints about this product may be raised in accordance
with the applicable terms of sale, provided that the
product has been used and maintained correctly.
The right of complaint may be voided if the system is
used incorrectly or maintenance is grossly neglected.
Complaints as a result of incorrect or defective installation
must be submitted to the installation company responsible.
Filters are consumables.
Our products are subject to continuous development
and we therefore reserve the right to make changes.
We also disclaim liability for any printing errors that
mayoccur.
8. Waste handling
The symbol on the product shows that this
product must not be treated as household waste.
It must be taken to a collection point for recycling
electrical and electronic equipment.
By ensuring correct disposal of the equipment, you will help
to prevent the negative consequences for the environment
and health that incorrect handling may entail.
For further information on recycling this product, please
contact your local authority, your refuse collection
company or the company from which you purchased it.

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NORDIC S4

Flexit AS, Moseveien 8, N-1870 Ørje
www.flexit.com
The product is listed in the
database for building products
that can be used in Nordic
Swan Ecolabelled buildings.
Flexit osallistuu asuntoilmastoinnin ECP-ohjelmaan.
Tarkista sertioinnin voimassaolo:
www.eurovent-certication.com