Flexit Nordic KS3 User manual

USER MANUAL
Air handling unit with optional kitchen hood connection
Nordic KS3
ART.NO. 800300, 800301
120320-02
2023-05
Flexit
GO

2
NORDIC KS3
Contents
1. Automatic control.........................................................................................................6
2. Functional description .................................................................................................7
2.1. Heating element ................................................................................................7
3. Door ...............................................................................................................................8
3.1. Unit door.............................................................................................................8
3.2. Design front/External front ..............................................................................8
4. Cleaning and maintenance .........................................................................................9
4.1. Cleaning the fans...............................................................................................9
 &KDQJLQJWKHȴOWHUV ........................................................................................ 10
4.3. Changing the brush strips ............................................................................. 11
4.4. Cleaning the rotor .......................................................................................... 13
5. Maintenance table .................................................................................................... 14
6. Troubleshooting ........................................................................................................ 15
7. Complaints ................................................................................................................. 16
8. Disposal...................................................................................................................... 16

3
NORDIC KS3
FRONTFRONT
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 Extract air
from kitchen
Outdoor air
Supply air
Exhaust air
DANGER:
ELECTRICITY
INFO! When a text box is this
FRORXULWbPHDQVWKDWLWFRQWDLQV
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)

4
NORDIC KS3
• To avoid the risk of fire, electric
shock or injury, read all the safety
instructions and warning texts
before using the unit.
• There is a fire risk if cleaning is not carried
out in accordance with the instructions.
• 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.
• The air must not be released into extract
air ducts used for air extracted from
appliances which burn gas or other fuel.
• CAUTION! Accessible parts may become
hot when used together with kitchen
equipment.
• Do not flame food under the kitchen hood.
• It is the installer’s responsibility to carry out
a full safety and function assessment of the
appliance.
• WARNING! Failure to install the screws
or fixing device in accordance with these
instructions may result in electrical hazards.
• Follow the current regulations for extract
air.
• Before opening the door: switch off the
KHDWOHWWKHIDQVFRQWLQXHIRUbPLQXWHVWR
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.
• Connection/disconnection to supply
mains and interconnection of separate
components must be possible.
• Allow disconnection of the appliance after
installation, by accessible plug or a switch in
the fixed wiring.
• Dette apparatet kan brukes av barn over
This appliance may be used by children of 8
years or above or by persons with reduced
!SAFETY
INSTRUCTIONS
!
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.

5
NORDIC KS3
• 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.
• If the supply cord is damaged,
it must be replaced by the
manufacturer, its service agent or
similarly qualified persons in order
to avoid a hazard.
• Applicable for Germany market only:
When the range hood and appliances
supplied with energy other than electricity
are simultaneously in operation, the
negative pressure in the room must not
exceed 4 Pa (4 × 10-5 bar).
i

6
NORDIC KS3
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,
VHHZZZȵH[LWFRP
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

7
NORDIC KS3
2. Functional description
Cold outdoor air passes through one half of the rotor
(HR-R), while warm extract air passes through the other
half, without the two mixing. Using this principle, a large
proportion of the heat in the extract air is transferred
to the supply air - the heat store principle (see system
sketches). If the outdoor temperature is extremely low, a
thermostat-controlled heating element (EB) also ensures
that the supply air has the desired temperature. This
supply air is passed via ducts and valves to living rooms
and bedrooms. The extract air is extracted either from
WKHVDPHURRPRUYLDGRRUJDSVRYHUȵRZJUDWLQJVWR
toilets and wet rooms. The used air is passed via a duct
V\VWHPEDFNWRWKHXQLWJLYHVR΋LWVKHDWDQGLVH[SHO-
led from the building via a roof cowl, combi-box or wall
grating.
When there is no need for recovery, the rotor will stop.
When outdoor temperatures are extremely low, it may
be necessary to use electric battery-type duct pre-
heating (accessory).
2.1. HEATING ELEMENT
The heating element is secured from overheating by the
F20 thermostat, which cuts out at 40°C. For extra safety,
the F10 thermostat cuts out at 80°C.
The F10 thermostat needs to be reset manually by
pressing the reset button.
<RXFDQȴQGWKHUHVHWEXWWRQE\RSHQLQJWKHXQLWGRRU
located just above the system plate on the electrical
compartment cover.
INFO! This is purely a ventilation
system and not a heating system.
The home must be heated in the
normal manner.
i
Outdoor Exhaust Extract Supply
air air air air
7
2
5
3
6
1
8
4
No. Abbreviation Description
1 FI2 ([WUDFWDLUȴOWHU
2 FI1 6XSSO\DLUȴOWHU
3 EB Heating battery
4 F10 Overheating thermostat, manual reset
4 F20 Overheating thermostat, automatic
reset
5 F10 reset button
6 M1 Supply air fan
7 M2 Extract air fan
8 HR-R Rotary wheel-type heat exchanger

8
NORDIC KS3
3. Door
!
DANGER! Before opening the door
of the heat recovery unit or carrying
out maintenance on the kitchen
KRRGVZLWFKR΍WKHKHDWOHWWKH
fans continue for three minutes to
remove hot air, disconnect power
from the unit and wait 2 minutes
before opening the doors.
!
DANGER! Remember that the unit
door (7 kg) and design front (5 kg)
are heavy when lifting them down
from the unit.
3.1. UNIT DOOR
1. Undo the four screws in the unit door
2. /LIWWKHGRRUR΋
1
3.2. DESIGN FRONT/EXTERNAL FRONT
1. Unhook the design front/external front
2. Undo the four screws in the unit door
3. /LIWWKHGRRUR΋
1 2 3
2
User manual
Flexit GO
User manual
NordicPanel
)RUPRUHLQIRUPDWLRQRQVZLWFKLQJR΋WKHKHDWLQJ
element, see the user manual for Flexit GO (117078) or
NordicPanel (120426).

9
NORDIC KS3
4. Cleaning and maintenance
!
DANGER! Before opening the door
of the heat recovery unit or carrying
out maintenance on the kitchen
KRRGVZLWFKR΍WKHKHDWOHWWKH
fans continue for three minutes to
remove hot air, disconnect power
from the unit and wait 2 minutes
before opening the doors.
4.1. CLEANING THE FANS
&OHDQWKHIDQVDWWKHWLPHLQWHUYDOVVSHFLȴHGLQFKDS
Maintenance table on page 14. 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.
!
CAUTION! If the unit is connected
to a kitchen hood and used
frequently, the extract air fan
must be checked, and if necessary
cleaned more often than indicated
in the maintenance table.
To avoid mixing the fans up, it is
best to disconnect one fan at a
time.
i
The fans are removed as follows:
TIP: You need a T20
• Remove the door as shown in the previous chapter.
• Undo the screws in the electrical compartment cover
DQGWDNHWKHFRYHUR΋
• Disconnect the electric quick-release contact in the
electrical compartment by pressing in at the same
time as pulling the contact apart.
• Pull the cable feeds out of the grooves.
• Remove the covers placed over the fans (2).
• Pull out the fans (3).
1
2
3
2
3
When the fans are replaced, they
must be pushed in firmly.
i

10
NORDIC KS3
4.2. CHANGING THE FILTERS
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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
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least once a year, preferably in the autumn (after the
pollen season). In areas with a lot of dust and contam-
LQDWLRQWKHȴOWHUVVKRXOGEHFKDQJHGLQWKHVSULQJDQG
autumn.
'LUW\ȴOWHUVFDQDPRQJRWKHUWKLQJVOHDGWR
• Reduced performance of the unit
• The unit becoming dirty
• Humidity damage
• Reduced indoor air quality
$ȴOWHUVXEVFULSWLRQLVUHFRPPHQGHGWRHQVXUHIXOO
EHQHȴWIURPWKHV\VWHP
!
It is important to use a Flexit
original filter.
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the ventilation unit may not work as intended. Flexit
therefore accepts no liability for any operating faults.
!
Change both filters (supply air and
exhaust air) at the same time.
!
Make sure that the filter is not
damaged during fitting. A damaged
filter reduces the unit’s power and
air purity.
!
Check that the filter’s seal is intact
before inserting the filter.
Then push the filter properly into
place to prevent air leakage.
CAUTION! The unit must not be
used without a filter.
!
Clogged filters may reduce heat
recovery in the ventilation unit and
cause humidity damage.
Please note that a complaint may be rejected if you use
DȴOWHURWKHUWKDQDQRULJLQDO)OH[LWȴOWHU
)RUWKHULJKWȴOWHUVHHȆ$FFHVVRULHVȇXQGHU\RXUXQLWRQ
)OH[LWȇVZHEVLWH
7KHȴOWHUVDUHUHPRYHGDVIROORZV
When replacing the filters, it is
important to push the short end
with the gasket in first.
i

11
NORDIC KS3
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 approximately 2-3 cm out.
5. Pull the cable feed attached to the side of the rotor
out of the groove.
2. 'LVFRQQHFWWKHURWRUȇVTXLFNUHOHDVHFRQWDFWIURP
the circuit board.
3. Also pull the cable lug out to disconnect the earth on
the circuit board.
e
.
5
6. Pull the rotor module right out and position it with
the brush strips facing up.
6
3
2

12
NORDIC KS3
7
98
LEVEL 1
LEVEL 2
8. Pull the brush strips out of the groove.
9. Move the brush strips down to level 2, or replace
them with new ones if they are completely worn out.
10. 3UHVVWKHEUXVKVWULSSURȴOHEDFNLQWRSODFH
7. )OLSR΋WKHEUXVKVWULSSURȴOHVZLWKDVFUHZGULYHUIRU
example. There are total of four brush strips on the
rotor, two on each side.
Use a broad screwdriver so you can get good pur-
FKDVHZLWKRXWEHQGLQJWKHSURȴOH6WDUWDWRQHHQG
and continue to the other. Lift it carefully, bit by bit.
10

13
NORDIC KS3
4.4. CLEANING THE ROTOR
$KLJKLPSHUPHDELOLW\ȴOWHULVLQVWDOOHGLQWKHXQLW
ΔWbLVbQRWWKHUHIRUHXVXDOO\QHFHVVDU\WRFOHDQWKHURWRU
ΔIbIRUbDQ\UHDVRQLWVKRXOGVWLOOEHQHFHVVDU\GXVWFDQ
EHbUHPRYHGZLWKDVRIWEUXVK
Further cleaning is possible by removing the rotor, spray-
ing 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.

14
NORDIC KS3
5. Maintenance table
Component Action Interval
Filter Filters must be changed at least once a year. It is best to do this twice a year, before and after
WKHbSROOHQVHDVRQ&KHFNWKDWWKHȴOWHUVHDOLVFRPSOHWHO\WLJKW
$VVWDQGDUGDPDLQWHQDQFHUHPLQGHUWRFKDQJHWKHȴOWHUZLOODSSHDUHYHU\PRQWKV
6-12 months
Fans The fan in a unit connected to a kitchen hood should be inspected once a year.
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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. 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
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.

15
NORDIC KS3
6. Troubleshooting
INFO! In the case of a power cut,
the unit will automatically return to
normal operation (user's settings)
when starting up again.
i
Type of fault Remedial action
Cold draughts Check which supply temperature has been selected. See operating panel.
Check that the rotor is rotating.
Check that heating comes on.
1HHGVQHZH[WUDFWȴOWHU
Fans not working Check that the power to the unit is connected.
Check that the overheating thermostat has not cut out.
Reset by pressing the button. Also needs correcting on the automatic control panel.
Check that the unit has not been set in stop position.
Low air volume Check the speed the unit is set to.
&KHFNWKDWWKHȴOWHUVȴWWLJKWO\
Check the intake grille.
When connecting a kitchen hood
The kitchen hood is
not working
Check that the cable between the kitchen hood and the unit is connected.
Poor extraction
above the kitchen
hood
&KHFNWKDWWKHJUHDVHȴOWHULVQRWEORFNHG
&KHFNWKDWWKHȴOWHUWRWKHH[WUDFWDLUIDQLVQRWEORFNHG
INFO! If none of this helps, please
contact your supplier for service.
Please state the model designation
and serial number (on the rating
plate inside the unit/open door).
i

16
NORDIC KS3
7. Complaints
Warranty claims will only be valid
if the instructions in the manuals
have been followed.
i
This product is covered by warranty in accordance with
the current terms of sale, provided that the product is
used correctly and properly maintained.
The warranty may be rendered invalid if the system is
used incorrectly or maintenance is grossly neglected.
Complaints resulting from incorrect or defective instal-
lation 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. Disposal
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 negative consequences for the environ-
ment 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.

17
NORDIC KS3

18
NORDIC KS3

19
NORDIC KS3

The product is listed in the
database for building products
that can be used in Nordic
Swan Ecolabelled buildings.
Flexit AS, Moseveien 8, 1870 Ørje, Norway
www.flexit.com
Flexit participates in the ECP programme for RAHU.
&KHFNRQJRLQJYDOLGLW\RIFHUWLȴFDWH
ZZZHXURYHQWFHUWLȴFDWLRQFRP