Zehnder Rittling ComfoAir 350 Basic Series User guide

Cooling Fresh Air Clean AirHeating
ComfoAir 350 Basic
Installer manual

EN - II
All rights reserved.
This manual has been compiled with the utmost care. The publisher cannot be held liable for any damage caused as a result
of missing or incorrect information in this manual. In case of disputes the Dutch version of these instructions will be binding.

III - EN
Table of Contents
Preface ............................................................................................................................................................. 1
1 INTRODUCTION ............................................................................................................................................. 1
1.1 Warranty and liability .......................................................................................................................... 1
1.1.1 Guarantee conditions ................................................................................................................ 1
1.1.2 Liability ...................................................................................................................................... 1
1.2 Safety ................................................................................................................................................... 2
1.2.1 Safety regulations...................................................................................................................... 2
1.2.2 Safety provisions and measures ............................................................................................... 2
1.2.3 Pictograms used ....................................................................................................................... 2
2 FOR THE FITTER ............................................................................................................................................ 3
2.1 ComfoAir configuration...................................................................................................................... 3
2.2 Technical specifications ..................................................................................................................... 4
2.3 Dimension sketch ............................................................................................................................... 6
2.4 Installation conditions ........................................................................................................................ 7
2.5 Installation of the ComfoAir ............................................................................................................... 7
2.5.1 Transport and unpacking........................................................................................................... 7
2.5.2 Checking the delivery ................................................................................................................ 7
2.6 Mounting of the ComfoAir.................................................................................................................. 7
2.6.1 Mounting on the wall ................................................................................................................. 7
2.6.2 Connection of the air ducts ....................................................................................................... 8
2.6.3 Connection of the condensation drain ............................................................................................... 8
2.7 Commissioning the ComfoAir............................................................................................................ 9
2.7.1 Display on the unit..................................................................................................................... 9
2.7.2 P menus for the installer.......................................................................................................... 10
2.8 Programming air specifications ...................................................................................................... 13
2.9 Maintenance by the installer............................................................................................................ 14
2.9.1 Inspecting and cleaning the heat exchanger........................................................................... 14
2.9.2 Inspecting and cleaning the fans............................................................................................. 15
2.10 Malfunctions...................................................................................................................................... 16
2.10.1 Malfunction alerts on the digital operating device .................................................................. 16
2.10.2 3-position switch with malfunction indicator........................................................................... 16
2.10.3 What to do in the event of a malfunction / Troubleshooting ................................................... 17
2.10.4 Malfunctions (or problems) without alerts ............................................................................... 21
2.11 Service parts...................................................................................................................................... 22
2.12 Wiring diagram: ComfoAir 350 Basic – LEFT-HAND version......................................................... 23
2.13 Wiring diagram: ComfoAir 350 Basic – RIGHT-HAND version ...................................................... 24
2.14 EEC declaration of conformity......................................................................................................... 25

EN - IV

1 - EN
Preface
Carefully read this manual before use.
This manual provides all the information required for
safe and optimal installation and maintenance of the
ComfoAir 350 Basic. It is also intended as a refer-
ence for servicing, so that this can be carried out in
a responsible manner. The device is subject to con-
tinuous development and improvement. As a result,
the ComfoAir 350 Basic may slightly differ from the
descriptions.
1 Introduction
The device's name is ComfoAir 350 Basic. In the fol-
lowing it will be referred to as ComfoAir.
The ComfoAir is a balanced ventilation system with
heat recovery in order to create healthy, balanced
and energy-efcient ventilation in houses. The Com-
foAir has a CE marking on the identication plate.
The identication plate can be found on top of the
ComfoAir.
1.1 Warranty and liability
1.1.1 Guarantee conditions
The ComfoAir is covered by a manufacturer’s war-
ranty for a period of 24 months after tting up to a
maximum of 30 months after the date of manufac-
ture. Warranty claims may only be submitted for ma-
terial faults and/or construction faults arising during
the warranty period. In the case of a warranty claim,
the ComfoAir must not be dismantled without written
permission from the manufacturer. Spare parts are
only covered by guarantee, if they were supplied by
the manufacturer and have been installed by an ap-
proved installer.
The warranty becomes invalid if:
■The guarantee period has elapsed;
■The device is used without lters;
■Parts are used that have not been supplied by the
manufacturer;
■Non-authorised changes or modications have
been made to the unit.
1.1.2 Liability
The ComfoAir has been designed and manufactured
for use in balanced ventilation systems incorporating
Zehnder heat recovery systems. Any other applica-
tion is seen as inappropriate use and can result in
damage to the ComfoAir or personal injury, for which
the manufacturer cannot be held liable.
The manufacturer is not liable for any damage origi-
nating from:
■Non-compliance with the safety, operating and
maintenance instructions in this manual;
■The use of components not supplied or recom-
mended by the manufacturer.
Responsibility for the use of such components
lies entirely with the installer;
■Normal wear and tear.

EN - 2
1.2 Safety
1.2.1 Safety regulations
Always comply with safety regulations in this manual.
Non-compliance with the safety regulations, warn-
ings, notes and instructions in this manual can cause
personal injury or damage to the ComfoAir.
■The ComfoAir may only be installed, connected,
rendered operational and maintained by an ap-
propriately approved installer, unless otherwise
indicated in this manual;
■Installation of the ComfoAir must be carried out in
accordance with the general and locally applica-
ble construction, safety and installation instruc-
tions of the local council, electricity and water
boards or other agencies;
■Observe the safety regulations, warnings, com-
ments and instructions as prescribed in this man-
ual at all times;
■Keep this manual with the ComfoAir throughout
its life;
■Instructions with regard to cleaning or replacing
the lters of the intake and exhaust valves must
be carefully observed;
■The specications stated in this document may
not be changed;
■Modifying the ComfoAir is not allowed;
■The ComfoAir is only suitable for connection to
230V 50Hz mains;
■It is recommended to take out a maintenance
contract so that the device is checked on a regu-
lar basis. The supplier can provide a list of regis-
tered installers nearby.
1.2.2 Safety provisions and measures
■The ComfoAir cannot be opened without using
tools;
■It should not be possible to touch the fans, there-
fore ducting must be connected to the ComfoAir
at a minimum duct length of 900mm.
1.2.3 Pictograms used
The following pictograms are used in this manual:
Point of attention.
Risk of:
- damage to the device;
- performance of the device is compro-
mised if instructions are not observed
carefully.
Risk of personal injury for the user or
installer.

3 - EN
2 For the Fitter
2.1 ComfoAir configuration
The standard ComfoAir conguration consists of:
■External casing (A) of coated sheeting;
■Interior (B) of high-quality, expanded polypropylene EPP;
■4 connections (C) for the air ducts;
■ 2 plate lters (D) for air purication. Filter classication: outside air G4, return air G4;
■2 energy-efcient DC motors (E) with high-efcient fan;
■HE (High efcient) heat exchanger (F);
■Control circuit board (H) with connections for the fans, the bypass, temperature sensors (T1 to T4), the 3-posi-
tion switch with or without malfunction indicator (optional) and the bathroom switch (optional);
■Identication plate (I) detailing information on the ComfoAir (not visible);
■Condensation drain (J) to drain the condensation of the warm return air;
■Sticker (K) detailing the air connections (not visible);
■Cable (L) for power supply (not visible).

EN - 4
2.2 Technical specifications
ComfoAir 350 nL (normal air volumes)
Position Ventilation capacity Power
Low Setting 100 m3/h at 20 Pa 21 W
Medium Setting 150 m3/h at 65 Pa 44 W
High Setting 225 m3/h at 150 Pa 105 W
Maximum 325 m3/h at 235 Pa 243 W
Position Ventilation capacity Current
Low Setting 100 m3/h at 20 Pa 0.17 A
Medium Setting 150 m3/h at 65 Pa 0.35 A
High Setting 225 m3/h at 150 Pa 0.81 A
Maximum 325 m3/h at 235 Pa 1.77 A
Electricity
Power supply 230/50 V/Hz
Cos.phi 0,50 - 0,60
Supply fan noise level (at 0 m)
Position Ventilation capacity Sound power
Low Setting 100 m3/h at 20 Pa 49 dB(A)
Medium Setting 150 m3/h at 65 Pa 59 dB(A)
High Setting 225 m3/h at 150 Pa 70 dB(A)
Maximum 325 m3/h at 235 Pa 75 dB(A)
Exhaust fan noise level (at 0 m)
Position Ventilation capacity Sound power
Low Setting 100 m3/h at 20 Pa 43 dB(A)
Medium Setting 150 m3/h at 65 Pa 48 dB(A)
High Setting 225 m3/h at 150 Pa 55 dB(A)
Maximum 325 m3/h at 235 Pa 61 dB(A)

5 - EN
ComfoAir 350 HL (high air volumes)
Position Ventilation capacity Power
Low Setting 125 m3/h at 25 Pa 27 W
Medium Setting 225 m3/h at 150 Pa 105 W
High Setting 300 m3/h at 230 Pa 196 W
Maximum 325 m3/h at 235 Pa 243 W
Position Ventilation capacity Current
Low Setting 125 m3/h at 25 Pa 0.21 A
Medium Setting 225 m3/h at 150 Pa 0.81 A
High Setting 300 m3/h at 230 Pa 1.42 A
Maximum 325 m3/h at 235 Pa 1.77 A
Electricity
Power supply 230/50 V/Hz
Cos.phi 0,50 - 0,60
Supply fan noise level (at 0 m)
Position Ventilation capacity Sound power
Low Setting 125 m3/h at 25 Pa 54 dB(A)
Medium Setting 225 m3/h at 150 Pa 67 dB(A)
High Setting 300 m3/h at 230 Pa 73 dB(A)
Maximum 325 m3/h at 235 Pa 75 dB(A)
Exhaust fan noise level (at 0 m)
Position Ventilation capacity Sound power
Low Setting 125 m3/h at 25 Pa 45 dB(A)
Medium Setting 225 m3/h at 150 Pa 55 dB(A)
High Setting 300 m3/h at 230 Pa 59 dB(A)
Maximum 325 m3/h at 235 Pa 61 dB(A)
General Specifications
HE Exchanger Material Polystyrene
Interior Material (E)PP / PA / PC
Thermal Yield 95%
Mass 39 kg

EN - 6
2.3 Dimension sketch
801 35
214
761
ø180
851
845
702
ø160
ø151
354 348
264
161
572
625
269
172 172
CONDENSATION DRAIN
LEFT-HAND VERSION
CONDENSATION DRAIN
RIGHT-HAND VERSION
CONDENSATION DRAIN ø32 (OUTSIDE)

7 - EN
2.4 Installation conditions
In order to determine whether the ComfoAir can be
installed in a certain area, the following aspects must
be taken into account:
■The ComfoAir must be installed according to the
general and locally applicable safety and installa-
tion regulations of power and water companies, as
well as the instructions in this manual.
■ The system must be tted to allow sufcient room
around the ComfoAir for the air connections and
supply and exhaust ducts as well as for carrying
out maintenance activities.
■
T he ComfoAir must be installed in a frost-free space.
The condensation must be drained off frost-free, at a
gradient and incorporate a 'U' bend.
We do not recommend installing the Com-
foAir in areas with a higher average humidity
(such as bathroom or toilet). This will prevent
condensation on the outside of the ComfoAir.
■The room must offer the following provisions:
- Air duct connections.
- 230V electrical connection.
- Provisions for the condensation drain.
- Wiring for a wired 3-position switch
(optional).
■A gap should be left near the doors in order to
ensure effective and draughtfree airow in the
house. A gap under the inside doors must be at
least 10mm.
If these openings are obstructed, due to
draught excluders or deep-pile carpet, the
airflow in the house will stagnate. As a result,
system performance will be compromised or
fail altogether.
2.5 Installation of the ComfoAir
2.5.1 Transport and unpacking
Take the necessary precautions when transporting
and unpacking the ComfoAir.
Make sure the packing material is disposed
of in an environmentally friendly manner.
2.5.2 Checking the delivery
Contact your supplier immediately in case of dam-
age or an incomplete delivery. The delivery should
include:
■ComfoAir;
Check the identication plate to ensure that it is
the required type.
■4 x 45Oconnection bends;
■Mounting bracket;
■Documentation.
The ComfoAir is supplied in the following types:
Type
ComfoAir 350 L Basic
ComfoAir 350 R Basic
Meaning of the sufxes:
* L = Left version
* R = Right version
2.6 Mounting of the ComfoAir
2.6.1 Mounting on the wall
Mount the ComfoAir against a wall with a minimum
mass of 200 kg/m2. For other types of wall, we recom-
mend using the Zehnder mounting frame on the oor
(available as an optional extra). This reduces contact
noise as much as possible. The ComfoAir does not
require any space at the sides for effective operation.
Do not mount the side of the ComfoAir
against the wall due to the risk of impact
sound.
1. Fasten the mounting bracket to the wall. Make
sure it is level and at least 878mm from the oor
(depending on the type of condensation drain se-
lected).
Leave a minimum space of 1m in front of the
ComfoAir for carrying out maintenance.
2. Hang the ComfoAir on the mounting bracket.
3. Mount the condensation drain under the Com-
foAir. The stated dimension of 235 mm is an in-
dication only, and is dependent on the type of
condensation drain selected.

EN - 8
2.6.2 Connection of the air ducts
The following aspects must be taken into account,
while installing the air ducts:
■Install the air exhaust duct so it drains in the di-
rection of the ComfoAir.
■Insulate the outside air supply and the air ex-
haust duct between the roof/wall passage to
render the ComfoAir damp proof. This prevents
the formation of condensation on the outside of
the ducts.
■To prevent unnecessary temperature loss in ei-
ther the summer or the winter, we recommend
tting thermal and damp-proof insulation to the
supply ducts from the ComfoAir up to the supply
valves.
■Install the air ducts with a minimum ø of 150
mm, as little air resistance as possible and free
from air leakage.
■Install a silencer of at least 1m straight directly
onto the supply and return air connections. For
relevant advice, please contact Zehnder.
■ When using exible channels only Zehnder
channel systems may be used. Any other exible
channel will disturb the basic operating principle
of the balanced ventilation system.
■ We recommend that the ventilation system is
tted with intake and exhaust valves made by
Zehnder.
Outside air
Exhaust air
Supply air
Return air
ComfoAir 350 - LEFT
Return air
Supply air
Exhaust air
Outside air
ComfoAir 350 - RIGHT
2.6.3 Connection of the condensation drain
ComfoAir 350 - LEFT
ComfoAir 350 - RIGHT
Warm exhaust air is cooled by the outside air in the
heat exchanger. This causes the moisture in the
indoor air to condense in the heat exchanger. The
condensation water created in the heat exchanger is
fed to a PVC condensation drain.
The connection for the condensation drain has an
external diameter of 32 mm. It is located underneath
the ComfoAir.
■Connect the condensation drain, via a pipe or
hose, to the water seal (U bend) of the domestic
waste-water system.
■Position the upper edge of the water seal at least
40 mm underneath the condensation drain of
the ComfoAir.
■Make sure that the outer end of the pipe or tube
exits is at least 60mm below the water level.
Ensure that the water seal connected to the
domestic waste-water system is always full
of water. This prevents the ComfoAir from
sucking in any leakage air.

9 - EN
2.7 Commissioning the ComfoAir
After installation, the ComfoAir must be commis-
sioned.
This can be done via the P menus on the digital op-
erating device. These P menus can be used to enter
various settings (ventilation programmes, in particu-
lar) for the ComfoAir. An overview of the available P
menus is given below:
Menu Options
P1 Reading statuses (from menu P2)
P2 Setting time delays
P3 Setting and reading the ventilation
levels
P4 Setting and reading the temperatu-
res
P5 Setting additional programmes
P6 Setting additional programmes
P7 Reading and resetting malfunctions
(and system information)
P8 N/A
P9 Reading statuses (from menu P5
and P6)
P menus P1, P2 and P9 can be accessed by the user,
mainly to read statuses and set time delays. The re-
maining P menus P3 to P8 are intended solely for
the installer.
The ComfoAir's bypass valve will not work
for the rst 4 minutes after a power cut un-
less the programme mode is activated.
2.7.1 Display on the unit
The ComfoAir can be operated and commissioned
by means of a display. The display is a digital op-
erating device which is mounted on the ComfoAir.
select menu up
OK down
supply off supply on
(led green) (led green)
comfort temperature
Shown in display
Ventilation setting absent
Ventilation setting low
Ventilation setting medium
Ventilation setting high
Menu symbol
Malfunction code (ashes)
Bypass
Access to the menus
Se-
quence
Press Display Description
1 MENU P2 Time delay
2s + ▼
(3 seconds)
P3 Press the buttons
simultaneously.
3sP4 Temperatures
4sP5 Settings
5sP6 Settings
6sP7 Malfunction / Reset /
Self-test
7sP8 0 - 10V Inputs
8sP9 Status
Example
Setting the MEDIUM POSITION of the supply fan to
40%.
Se-
quence
Press Display Description
1 MENU P2 Time delay
2s + ▼
(3 seconds) P3 Press the buttons simultaneously.
3 OK P30 Exhaust fan
Position A
4s (6x) P36 Select P36
5 OK 50 Current setting
6
▼ (10 x or
press con-
tinuously)
40 Select 40
7 OK P35 Value is 40
8 MENU P3
9 MENU 1 Fan setting
Some P menus (such as P1 and P9) can only
be read.
Leaving Reading menu
• At action point 6 press "MENU" (instead of
"OK").
The display can not be used for setting the
ventilation positions of the ComfoAir. The
arrowkeys are only for setting the additional
programmes.
OK
MENU
·
·
·
OK
MENU
·
·
·
OK
MENU
·
·
·
OK
MENU
·
·
·
OK
MENU
·
·
·
1
A
2
3
X X
X X
•
1
A
2
3
X X
X X
•
1
A
2
3
X X
X X
•
1
A
2
3
X X
X X
•
1
A
2
3
X X
X X
•
1
A
2
3
X X
X X
•
1
A
2
3
X X
X X
•

EN - 10
2.7.2 P menus for the installer
Menus with a line at minimum and maximum value are Reading menus.
Menu P3 ¨Setting ventilation programmes
Ventilation programme values
Submenu Description Minimum Maximum General
Reset
P30 n/a 0% or 15% 97% nL / HL
15% / 15%
P31 Setting the capacity (in %) of the
exhaust fan in
low position
.
16% 98% nL / HL
35% / 40%
P32 Setting the capacity (in %) of the
exhaust fan in
medium position
.
17% 99% nL / HL
50% / 70%
P33 Setting the capacity (in %) of the
exhaust fan to
high position.
18% 100% nL / HL
70% / 90%
P34 n/a 0% or 15% 97% nL / HL
15% / 15%
P35 Setting the capacity (in %) of the
supply fan in
low position
.
16% 98% nL / HL
35% / 40%
P36 Setting the capacity (in %) of the
supply fan in
medium position
.
17% 99% nL / HL
50% / 70%
P37 Setting the capacity (in %) of the
supply fan in
high position
.
18% 100% nL / HL
70% / 90%
P38 Current capacity (in %) of the
exhaust fan.
- - Current %
P39 Current capacity (in %) of the
supply fan.
- - Current %
Menu P4 ¨Reading the temperatures
Temperature values
Submenu Description Minimum Maximum General
Reset
P41 Comfort temperature 12 oC 28 oC 20 oC
P45 Current value of T1
(= outside air temperature)
- - Current oC
P46 Current value of T2
(= supply air temperature)
- - Current oC
P47 Current value of T3
(= return air temperature)
- - Current oC
P48 Current value of T4
(= exhaust air temperature)
- - Current oC

11 - EN
Menu P5 ¨Setting additional programmes
Additional programme values
Submenu Description Minimum Maximum General
Reset
P50 Activation of the open re programme. 0 (= No) 1 (= Yes) 0
P51 n/a 0 (= No) 1 (= Yes) 0
Always keep this setting on Default.
P52 n/a 0 3 2
P54 Conrming the presence of a bypass. 0 (= No) 1 (= Yes) 1
The standard ComfoAir conguration includes a bypass. Therefore, leave the value at ‘1’.
P56 Setting the required air volume in the house.
■nL: ”normal air volume”.
■HL: "high air volume".
nL HL HL
Setting the air volume is the starting point for programming the air specications and setting the fans.
P57 Setting the ComfoAir type.
■Li = ”Left-hand version”.
■Re = ”Right-hand version”.
Li Re Li
With delivery the ComfoAir is correctly pre-programmed at the factory.
After a general reset the pre-programming is lost and the setting must be reset.
The correct setting is mentioned on the identication plate on top of the ComfoAir.
P58 n/a 0 1 0
P59 n/a 0 (= No) 2 (= Yes) 0
Always keep this setting on Default.
Menu P6 ¨Setting additional programmes
Additional programme values
Submenu Description Minimum Maximum General
Reset
P60 n/a 0 (= No) 3 (= Yes) 0
Always keep this setting on Default.

EN - 12
Menu P7 ¨Reading malfunctions (and system information)
(Malfunction) information values
Submenu Description Minimum Maximum General
Reset
P70 Current software version. Version number of the software (without “v”)
P71 Most recent malfunction. Code in accordance with alarm and malfunction alert
P72 Malfunction before the most recent one Code in accordance with alarm and malfunction alert
P73 Malfunction before the most recent two Code in accordance with alarm and malfunction alert
P74 Resseting malfunction(s)
■Set value to '1' and press "OK" on the
display.
0 1
(= activate)
0
P75 General reset.
■press "OK" on the display for at least 5
seconds to carry out a general reset.
All original software settings are restored
following a general reset.
0 1
(= activate)
0
After a general reset, the ComfoAir will ask you to reset the “nL / HL” (see P56) and “Li
/ Re” (see P57) settings.
Following a general reset, all settings and programmes need to be checked and set to
the right value.
P76 Self-testing the ComfoAir 0 1
(= activate)
0
• The ComfoAir will run at maximum Rotations Per Minute (RPM).
• The bypass valve will open and close.
P77 Resetting lter dirty counter 0 1
(= activate)
0
This resets the counter that triggers a dirty lter alert on the ComfoAir. This allows the lter to be
cleaned or replaced before the dirty lter alert appears.
Menu P8 ¨N/A
Analogue input values
Submenu Description Minimum Maximum General Reset
850 n/a 0 1 0
851 n/a 0 1 0
852 n/a 0 100 50
853 n/a 0 99 0
854 n/a 0 100 100
855 n/a 0 1 0
856 n/a 0 100 -

13 - EN
2.8 Programming air specifications
After installation, the ComfoAir must be programmed.
This can be done using the air specications of the
ComfoAir above.
The default settings of the ComfoAir nL are:
Position
low
35%
Position
medium
50%
Position
high
70%
The default settings of the ComfoAir HL are:
Position
low
40%
Position
medium
70%
Position
high
90%
Follow this procedure to programme the ComfoAir
(after installation):
1. Set the ComfoAir in programming mode.
- Press simultaneously for at least 3 seconds on
"" and " " until “InR” appears on
the display.
In programming mode, the bypass and valve
is valves are always closed. After 30 minutes,
the ComfoAir automatically terminates the
programming mode.
2. Close all windows and outside doors.
3. Close all inside doors.
4. Check the presence of structural overow provi-
sions.
5. Check if both fans function in the three speed set-
tings.
6. Switch the ComfoAir to high speed.
7. Install all valves and set the valves according to
the settings given or as set in the reference house.
8. Change the fan settings in P menus P30 to P37 of
the digital operating device if required.
Use the chart of the ComfoAir's air specica-
tions to set the fans.
9. In the event that the currently set air volumes still
deviate too much: Adjust the valves.
10. Check the entire installation again, after all valves
have been set.
11. Switch the ComfoAir (back) to ventilation position
1.
- Press simultaneously for at least 3 seconds on
"" and " " until “InR” disappears of
the display.

EN - 14
2.9 Maintenance by the installer
The following maintenance must be carried out by the
installer:
■Inspecting and (if necessary) cleaning the heat
exchanger;
■Inspecting and (if necessary) cleaning the fans.
A concise explanation of these maintenance activities
is given in the paragraphs below.
Check the condensation drain once every 5
years.
Failure to carry out (periodic) maintenance
on the ComfoAir ultimately compromises the
performance of the ventilation system.
2.9.1 Inspecting and cleaning the heat
exchanger
Check the heat exchanger once every 5
years.
1. Disconnect the power from the ComfoAir.
2. Remove the handles (B) from the ComfoAir;
3. Remove the lters from the ComfoAir.
4. Release the front panel by unscrewing the screws
(C).
5. Slide the front panel upwards and remove the
front panel from the ComfoAir.
C
B
A
6. Release the cover panel by unscrewing the
screws (D).
7. Remove the cover panel.
When reassembling the front cover, the
lower section must rst be inserted behind
the raised edge to ensure a good seal.
D
ComfoAir – Left-hand version
8. Pull the strap (E) to remove the heat exchanger
and the leakage tray (F).
9. Remove the bypass duct (G) in the left-hand ver-
sion of the ComfoAir.
ComfoAir – Right-hand version
8. Remove the bypass duct (G) in the right-hand
version of the ComfoAir.
9. Pull the strap (E) to remove the heat exchanger
and the leakage tray (F).
E
F
G
E
F
G
10. Remove the heat exchanger from the leakage tray
(F).
The heat exchanger may contain some re-
sidual water!

15 - EN
When reassembling the leakage tray the
openings in the leakage tray must be on the
side of the condensation drain.
11. Inspect and if necessary clean the heat exchang-
er.
- Use a soft brush to clean the ns.
- Use a vacuum cleaner or air gun (no high
pressure) to remove dirt and dust.
Always clean against the direction of
the airflow. This prevent dirt from get-
ting stuck in the heat exchanger.
Standard heat exchanger only:
a. Submerge the heat exchanger several times in
hot water (max. 40 °C).
b. Rinse the heat exchanger with clean hot tap wa-
ter (max. 40 °C).
c. Clasp the heat exchanger between both hands
(on the coloured side surfaces) and shake the wa-
ter from the heat exchanger.
Do not use aggressive cleaning agents or
solvents.
If the fans also need maintenance do not re-
install the heat exchanger yet.
12. If no more maintenance is necessary install all
parts in reverse order, reconnect the power and
carry out the self-test in accordance with menu
P76.
Fasten the screws to a maximum of 1.5 Nm.
This is roughly equal to speed 2 of an aver-
age battery-powered drill.
2.9.2 Inspecting and cleaning the fans
Check the fans once every 2 years.
1. Remove the heat exchanger as instructed in the
maintenance chapter of the heat exchanger.
2. Remove the small plastic panel (H) in front of the
control circuit board panel by unscrewing the
two screws.
3. Release the connectors (K) and the earth wire on
the control circuit board panel and fully remove the
cables including the two grommets (K).
4. Remove the entire scroll casing (L) by pressing
the click fasteners.
5. Remove the inow nozzle by pressing the click
fasteners surrounding the scroll casing.
6. Inspect and if necessary clean the fans.
- Use a soft brush to clean the fan impellers.
- Use a vacuum cleaner to remove dust.
L
K
H
Do not damage the fan impellers or tempera-
ture sensor.
7. If no more maintenance is necessary install all
parts in reverse order, reconnect the power and
carry out the self-test in accordance with menu
P76.
Fasten the screws to a maximum of 1.5 Nm.
This is roughly equal to speed 2 of an aver-
age battery-powered drill.

EN - 16
2.10 Malfunctions
Malfunctions in the ComfoAir are reported as follows:
■The malfunction alert appears on the display;
■The malfunction indicator on the 3-position
switch lights up.
Malfunction alerts may not appear on the digital oper-
ating device in all cases, even though there is a mal-
function (or problem). A concise explanation of both
types of malfunction (or problem) is given in the fol-
lowing paragraphs.
2.10.1Malfunction alerts on the digital
operating device
In the event of a malfunction, the corresponding mal-
function code will be displayed on the digital operat-
ing device of the ComfoAir.
Below is a list of the malfunction alerts on the digital
operating device.
In the chapter about troubleshooting is explained
how to solve these malfunctions
Code Description
A1 NTC sensor T1 is defective.
(= outside air temperature)
A2 NTC sensor T2 is defective.
(= supply air temperature)
A3 NTC sensor T3 is defective.
( =return air temperature)
A4 NTC sensor T4 is defective.
(= exhaust air temperature)
A5 Malfunction in the bypass motor.
A6 n/a
A7 n/a
E1 Exhaust fan not rotating.
E2 Supply fan not rotating.
EA2 n/a
‘Fil’ ‘tEr’ Internal Filter is dirty.
2.10.2 3-position switch with malfunction
indicator
The 3-position switches that are tted with a malfunc-
tion indicator show when a malfunction or lter dirty
alert has occurred. In the event of a malfunction or
lter dirty alert the indicator lights up;