OSTBERG HERU S AC Series Manual

UL VERSION. Choose language and unit system in the Setting Menu on page 15.
Installation and
directions for use
HERU S AC

WARRANTY
Warranty period valid according to purchase contract
calculated from date of purchase.
SCOPE OF WARRANTY
This warranty covers faults occurring during the war-
ranty period, which have been notified to the dealer
or verified by Ostberg Americas Inc. (warrantor) or a
representative of the warrantor, and which concern
design, manufacturing or material defects and conse-
quential damages occurring on the product itself.
The above mentioned faults will be rectified so that
the product is made operational.
GENERAL WARRANTY LIMITATIONS
The warrantor’s responsibility is limited in accordan-
ce with these warranty terms and the warranty does
not cover property damage or personal injury. Verbal
promises made in addition to this warranty agree-
ment are not binding for the warrantor.
WARRANTY LIMITATIONS
This warranty applies on condition that the product
is used in a normal fashion or under comparable circ-
umstances for its intended purpose and that the
instructions for use are followed.
This warranty does not cover faults caused by:
- Transport of the product.
- Careless use or overstraining of the product.
- Failure on the part of the user to follow instruc-
tions concerning installation, use, maintenance,
care and handling.
- Incorrect installation or incorrect positioning of
the product.
- Conditions that are not due to the warrantor, e.g.
excessive voltage variations, lightning, fire and
other accidents.
- Repair, maintenance or design changes made by
an unauthorized party.
- Faults that do not impact operation, e.g. surface
scratches.
- Parts that through handling or normal wear are
exposed to greater than average hazard, e.g. lamps,
glass, ceramic, paper and plastic parts, and filters
and fuses are not covered by the warranty.
- Settings; information on use, care, handling, service
or cleaning that are customarily described in the
instructions for use; or works caused by the user
neglecting to observe warning or installation
instructions; or investigation of such are not
covered by the warranty.
- The warrantor is responsible only for the operation
if approved accessories are used.
- The warranty does not cover product failures
caused by accessories/equipment from other
manufacturers.
The unit’s current settings must be noted in the
installation/mounting instructions at installation to
avoid costs in the event of fault. The warrantor is not
liable for costs such as adjustment costs related to
the replacement of fans and control boards in the
unit.
SERVICE TERMS DURING
THE WARRANTY PERIOD
According to your agreement with your local distri-
butor.
RECTIFICATION MEASURES
WHEN A FAULT IS DETECTED
When a fault is detected, the customer must notify
this to the dealer. Specify what product this applies
to (part number and manufacture date – year and
week – are listed on the product label), and describe
the fault and how it occurred as accurately as pos-
sible. For a warranty repair to be performed, the cus-
tomer must prove that the warranty is valid by pre-
senting the receipt of purchase. After the warranty
period has expired, warranty claims that have not
been made in writing before the expiration of the
warranty period will not be valid.
In all other respects according to our conditions
of sale.
NOTE!
Ostberg Americas Inc. reserve the right to make
changes without further notice.

WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
UNIT DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . .4
INSTALLATION AND SECURITY . . . . . . . . . . . . . .5
”USE” ”SECURITY” ”MOUNTING” . . . . . . . . . . . . . . . . .5
”PLACING” ”FREE SPACE” . . . . . . . . . . . . . . . . . . . . . . .6
”ASSEMBLY INSTRUCTIONS” . . . . . . . . . . . . . . . . . . . . . .6
”SCHEMATIC DIAGRAMS FOR PLACING” . . . . . . . . . . . .6
STARTING UP THE UNIT . . . . . . . . . . . . . . . . . . . .7
CONTROL DIAGRAM . . . . . . . . . . . . . . . . . . . . . .8
REGULATION FUNCTIONS . . . . . . . . . . . . . . . . . .9
OPERATING THE CONTROL UNIT . . . . . . . . . . .10
VIEW MODES 1-3 . . . . . . . . . . . . . . . . . . . . . . . .11
MAIN MENU . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
”FAN SPEED” MENU . . . . . . . . . . . . . . . . . . . . . .12
”TEMPERATURE” MENU . . . . . . . . . . . . . . . . . . .12
”BOOST” MENU . . . . . . . . . . . . . . . . . . . . . . . . .12
”OVERPRESSURE” MENU . . . . . . . . . . . . . . . . . .13
”WEEK TIMER” MENU . . . . . . . . . . . . . . . . . . . .13
”POWER ON/OFF” MENU . . . . . . . . . . . . . . . . .14
”ALARMS” MENU . . . . . . . . . . . . . . . . . . . . . . . .14
”SETTINGS” MENU . . . . . . . . . . . . . . . . . . . . . . .15
THE ”SERVICE MENU” . . . . . . . . . . . . . . . . . .15-23
”PRESSURE INPUTS” ”FILTER MEASUREMENT”
”AC FAN SETUP” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
”DISPLAY CONTRAST” ”BOOST”
”OVERPRESSURE” ”MAX TEMPERATURE” . . . . . . . . . . .17
”ALARM” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
”CO2” ”RH” ”HEATER” . . . . . . . . . . . . . . . . . . . . . . . .19
”COOLER” ”SUPPLY LIMITS”
”REGULATION MODE” ”MODBUS” . . . . . . . . . . . . . . . .20
”SUMMER COOLING” ”FREEZE PROTECTION”
”FLOW DIRECTION” . . . . . . . . . . . . . . . . . . . . . . . . . . .21
”SENSOR CALIBRATION” ”LOAD/SAVE SETTINGS”
”VERSION INFO” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
”DEVICE PAIRS” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
CHANGING FROM EC TO AC MODE . . . . . . . . .23
OTHER FUNCTIONS . . . . . . . . . . . . . . . . . . . . . .23
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24-25
ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . .26
SPARE PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . .27
ERROR DETECTION DIAGRAM . . . . . . . . . . .28-29
ERROR DETECTION . . . . . . . . . . . . . . . . . . . . . . .30
INTERNAL SETTINGS . . . . . . . . . . . . . . . . . . . . .31
DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . .34
FLOW DIRECTION . . . . . . . . . . . . . . . . . . . . . . . .35
TECHNICAL DATA . . . . . . . . . . . . . . . . . . . . . . . .35
SOUND DATA . . . . . . . . . . . . . . . . . . . . . . . .36-37
PRESSURE/FLOW DIAGRAMS . . . . . . . . . . . .38-39
WIRING DIAGRAMS . . . . . . . . . . . . . . . . . . .40-41
TECHNICAL INFORMATION
CONTENTS

UNIT DESCRIPTION
This ”Installation and directions for use” contains following products:
HERU 14 S AC, HERU 19 S AC, HERU 35 S AC and HERU 52 S AC.
IMPORTANT! Please read this manual before installing the unit.
HERU 14 S AC
HERU 19 S AC
HERU 35 S AC
• HERU S is approved according to the standard
UL 1812 ”Ducted Heat Recovery Ventilators” and
CSA-C22.2 No. 113 ”Fans and Ventilators”.
• HERU S is a heat recovery unit (HRV) or an ener-
gy recovery unit (ERV). It is designed for supply
and exhaust air ventilation combined with heat
and cool recovery.
• HERU S can be used in both residential and com-
mercial applications such as homes, apartments,
offices and schools etc. where there is a need for:
-clean. filtered and fresh air
-high temperature efficiency
-energy saving
-safe and quiet operation
• HERU S;
- has a rotating heat exchanger, of hygroscopic or
non-hygroscopic type and is manufactured of alu-
minium, placed centrally in the unit. The ERV ex-
changer has a humidity efficiency of up to 85%.
The HRV exchanger has a temperature efficiency
of up to 85%.
- has backward curved centrifugal fans with main-
tenance free external rotor motors, which are con-
nected with quick contacts, and are easy to
remove for cleaning.
- has built-in control for heating/cooling.
- can be fitted with a built-in electric heater.
- has as standard, disposable bag filters,
class MERV 13.
- has a wireless remote controller for the operation
and monitoring of the unit.
- has as standard, Modbus communication via
RS485.
- has a double skinned galvanised sheet steel casing
with intermediate insulation.
• The HERU S can be mounted in either warm or
cold space.
• The HERU S is delivered galvanized.
• All HERU S are operated via a wireless remote
controller which can operate and to preset the re-
quired parameters as well as monitor the unit’s
status. The operating range is approximately 50
meters/164 feet.
The antenna which is placed next to the unit can
have the range reduced if there are heavy reinfor-
cing bars in the concrete structure and it should
then be moved either to a position where the sig-
nal is not shielded or nearer to the controller.
HERU 52 S AC
4

INSTALLATION AND SECURITY
USE
• To achieve as comfortable indoor climate as pos-
sible and to avoid moisture damage to the proper-
ty, the house needs a continuous and adequate ven-
tilation. The unit must run continuously and only
be stopped for maintenance.
The air flow is controlled by settings in the wire-
less control unit:
Away – Reduced airflow, can be used when no one
is at home.
Normal – This is adjusted by the installer and
should not be changed by the user.
Boost – A higher air flow than normal, selectable
medium/max. Should be used when there is a need
for a higher air flow than the default mode is
adjusted for, such when cooking, drying laundry,
shower and sauna.
Recommendations for drying laundry: Because of
the high moisture content, an exhaust air tumbler
or a drying cabinet should not be connected to the
system. We recommend a condensing tumbler
without duct connection.
• When installing HERU consideration must be
given to any approval authority requirements and
recommendations concerning siting, accessibility,
electrical connections, etc.
• The HERU unit is accessible for the user, accor-
ding to IEC 60335-2-40, to by themselves do the
service and maintenance, according to this
Directions for use. But before this work the unit
must be currentless.
With reservation according to IEC 60335-2-7.12
”This appliance is not intended for use by persons
(including children) with reduced physical, senso-
ry or metal capabilities, or lack of experience and
knowledge, unless they have been given supervi-
sion or instruction concerning use of the appliance
by a person responsible for their safety.”
”Children should be supervised to ensure that they
do not play with the appliance.”
• The HERU unit should be storage in a sheltered
and dry place before installation.
• Dimensioned air flow should not exceed 60% of
the unit's maximum capacity.
• Check at regular intervals that supply air and ex-
haust air works.
•To avoid condensation in the unit during the cold
season, the unit should not be turned off for a
longer period. When installed in warm moisturre
environment as e.g. bathroom and utilityroom con-
dense may appear on the outside of the unit at low
outside temperatures.
SECURITY
Caution! Do not apply electric power until after
completion of the installation. Ensure the installation
and wiring is in accordance with CEC, NEC and
local electrical codes..
• Attention, look out for sharp edges and corners on
the HERU unit and fans.
• Consider the weight of the unit. See page 35.
• Before maintenance work the HERU unit must be
currentless. If there is a need of changing or comp-
lement any electrical components, it should be
done by a qualified person.
• The HERU unit includes rotating parts that could
cause serious danger on the occasion of contact.
This is why the unit must be duct connected and
the lid closed with the screws tightened, before
starting up the unit.
• After the current is cut for service and maintenan-
ce the electric heater may still be warm.
• Make sure that the access cable is not damage
when mounting and installation.
• HERU must be equipped with residual-current
device (RCD).
• The HERU S needs a permanent electrical supply.
• The unit must be connected via a safety switch.
Any electrical connections must be made by a qua-
lified electrician.
• Keep in mind that rotating, warm and electrical
components can cause serious damage.
MOUNTING THE HERU S
• HERU S should be installed according to the
assembly instructions. See picture on next page.
• Place the unit on a insulation board, min. 2 inch.
• Supply and exhaust air must be duct connected on
the same side of the unit.
• Acoustic silencer should be planned with the help
of sound data and required sound levels.
• Use duct clamp or flange with encompassing insu-
lation when connecting to duct.
• If the supply and the exhaust air ducts are installed
in a cold space they should be insulated. To pre-
vent condensation the supply air duct should also
be insulated if installed in warm space at low supp-
ly air temperatures.
• The fresh air and extract air duct should always be
condense insulated.
• The ducts should be insulated all the way towards
the unit.
• The duct sensor GT7 should be mounted in the
supply air duct, and the antenna on a suitably posi-
tion beside the unit (not against metal).
• If a heating coil is connected a cut off damper must
be mounted in the fresh air duct.
• Cooker hoods must not be connected to the
HERU S because of the increased cleaning de-
mand.
• Ducting must be conntected to external ground on
the unit, see picture.
External
ground.
5

SCHEMATIC DIAGRAM FOR HERU S PLACED IN AN ATTIC
ASSEMBLY INSTRUCTION
6
PLACING THE HERU S UNIT
The HERU S should be installed with the lid upwards (A) or on the side (B). Because of the risk of injury
we do not recommend installing the unit vertically (C) or with the lid downwards (D). Allowances must be
made to access the unit for servicing or maintenance.
A B C D
Inch A+D B C
H E R U 14 S/19 S 217/8 311/2 16
H E R U 35 S 24 393/8 201/2
H E R U 52 S 28 48 247/8
Clearance for servicing
and maintenance
CLEARANCEE FOR SERVICING
AND MAINTENANCE
INSULATION BOARD
min. 2 inch
FLOOR

7
WARNING!
Improper installation, adjustment, alternation, servi-
ce or maintenance can cause property damage, per-
sonel injury or loss of life.
Installation and service must be performed by a
qualified installer or service agency.
Carefully read through the manual before starting
up the unit.
• NB! Always mount the temperature sensor GT7 in
the supply air duct. See page 8. GT7 is connec-
ted at the relay card.
• The antenna should be mounted outside the unit.
The antenna for HERU S is connected ans is loca-
ted in the connection box when delivered.
NB! The antenna should not be mounted against
any metal area or metal items as this will shield
the signal.
The antenna should be mounted as central as
possible. This to achieve the best signal all over
the house. If needed an extension cord is available
as an accessorie.
• Install the 3 AA batteries in the wireless control
unit that are placed inside the HERU®when deli-
vered.
• HERU starts automatically (with a few minu-
tes delay) when the power is switched on, or
alternative with the wireless control unit.At power
outage, always check so the unit is starting up
again.
•HERU S is supplied for right handed application,
see picture below. If the unit is installed left
handed, and no electrical heater is fitted, changes
can be made in the ”Service Menu” and in the sub-
menu ”Flow Direction”. See page 20.
• Important when adjusting the flow: Go to Service
Menu (password 1199), choose “AC -motor setup”.
This disable functions such as Summer cooling or
Boost during flow adjustment. The fan speed is
standard. See page 21.
When adjusting the airflow of AC-fans there is a
possibility to change the voltage for the different
fan speeds via the separate transformers for supply
resp. exhaust fan. Normal operation should be
done in standard mode. Wiring diagrams with trans-
former steps see pages 40-41.
All HERU S has 7-step transformers. See wiring
diagrams on pages 40-41.
Note! When ajusting fan speed manully, make
sure that the speed keeps the sequences.
• All HERU can be fitted with a built-in electric
heater. Choose heater ”On/Off” according to the
instruction on page 19. For a heating coil see
instruction on page 19.
• Set the temperature according to the instruction
on page 12.
• Save settings according to the instruction on page
22.
•Note! The unit must not be operating without
filter.
STARTING UP THE UNIT NB! Important information before starting!
SUPPLY
AIR
FRESH
AIR
EXHAUST
AIR
EXTRACT
AIR
CONTROL CABINET

8
CONTROL DIAGRAM HERU S shows all sensors, flow direction right
*
*
*
*
*
*
*
*
*
*
*
*
*
*Accessories

9
REGULATE THE TEMPERATURE
The air temperature can be regulated either for con-
stant supply air temperature, constant room temper-
ature or constant exhtract air temperature.
For constant room temperature a sensor should be
placed in the room for room regulation (this is also
suitable when a cooling coil is incorporated in the
system).
Extract air regulation functions in a similar way
but with the difference being that the sensor is
placed at the extract air of the unit.
The temperature can be regulated in 5 sequences:
1.Cooling recovery + After cooling: The regulation
unit can regulate a cooling coil (e.g. cooling water
from bedrock), when the cooling recovery from
the rotor is not enough.
2.Cooling recovery or regulated after cooling: The
rotary heat exchanger starts if the extract air tem-
perature is lower than outside temperatur.
Regulated after cooling: The aftercooling starts
when the outside temperature is lower than de-
sired room temperature and is not enough to lower
the room temperature.
3.Outside temperature =desired temperature: When
the outside temperature is the same as desired sup-
ply air temperature the rotor stops.
4.Heat recovery: The rotary heat exchanger starts to
recover the warmer room temperature.
5.Heat recovery + heat: In climate conditions where
the rotary heat exchanger, in spite of its high effi-
ciency, is not sufficient to reach the desired supply
air temperature, the controller can regulate either
the built-in electric duct heater or a heating coil.
FAN CAPACITY
Airflow (fan speed) is regulated via the week timer
that can be programmed for specific time points
when the fan speed should change from one speed to
antoher (e.g. home or away setting).A special feature
is that you can pressure compensate when supple-
mentary heating, using an open fire or stove (the
extract air fan then drops to a lower speed).
With the weektimer function it is possible to
schedule different fan speeds e.g away/boost or
standby. The fan speed can also be controlled by a
carbon dioxide (CO2) and humidity (RH) sensor so
that the unit gives a higher airflow (boost) when the
maximum limit value has been exceeded.
”Summer Cooling” is a function where you can use
the cool outside temperature to cool down the inside
air. The fan speed is boosted when the ratio between
the outside temperature and the extract air temper-
ature is within the programmed criteria.
Via the wireless control unit the HERU can be put in
an ”Off mode”, which means that the motors for fans
and rotor are ”Off” but the unit is ”Stand by”. If there
is a requirement of totally cut off power, a discon-
nect switch must be mounted on the main electrical
feed.
Boosting the airflow for a specified time can be done
via the wireless control, there is also a opportunity to
do that via a timer connected to the ”0” and ”Boost”
connection on the PCB. With the connectors closed
the boost function will be ”On”.
REGULATION FUNCTIONS
3.
Outside temperature = Desired temperature
1.
Cooling recovery
+
After cooling
2.
Cooling recovery
or After cooling
4.
Heat recovery 5. Heat recovery
+
After heat
Regulated
after cooling
0-100%
Regulated
after heating
0-100%
Rotor 100%
Regulated rotor
0-100%
Rotor 100%
Regulated rotor
0-100%

10
OPERATING THE CONTROL UNIT
Std
SYSTEM OK ...
StdStd
SYSTEMSYSTEM OK ......
To activate or disable the keylock;
press down the key for 3 seconds.
VIEW MODE 1 shows alarm and VIEW MODE 2 shows what kind of alarm.
Information of the units current status such as temperature, fan speed, the rotor temperature efficiency when
operating, heat respectively cooling needs is shown in the VIEW MODE 1, 2, 3 and 4. These menus is normally
not lit up for battery-saving purposes but is lit up after the first press of the button and is switched off after
about 2 minutes of not being in use.
The control unit automatically returns to VIEW MODE 1 after one minute when one has viewed other submenus.
NB! At new setting a delay of 15 seconds should be taken into consideration.
Bottom row shows the
possible choices with
key or .
E.g turn on/off the unit
with the key.
Top row and
middle field
displays current
values and
activities.
Changes or modifications not expressly approved by the
party responsible for compliance could void the user’s aut-
hority to operate the equipment.
This exuipment has been tested and found to comply
with the limits for Class B digital device, pursuant to part
15 of the FCC Rules. These limits are digned to provide
reasonable protection against harmful interference in a
residential installation. This equipment generates, uses and
can radiate radio frequency energy and, if not installed and
used in accordance with the instruction, may cause harm-
ful interference to radio communications. However, there
is no guarantee that interference will not occur in a parti-
cular installation. If this equipment does cause harmful
interference to radio or television reception, which can be
determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one or
more of the following measures: -Reorient or relocate the
receiving antenna. -Increase the separation between the
equipment and receiver. -Connect the equipment into an
outlet on a circuit different from that to which the recei-
ver is connected. Consult the dealer or an experienced
radio/tv technician for help.
FCC ID: ASW-4020527
This device complies with part 15 of the FCC Rules
and RSS-210 of IC Rules. Operation is subject to
the following two conditions: (1) This device may
not cause harmful interference, and (2) this device
must accept any interference received, including
interference that may cause undesired operation of
the device.
USER INFORMATION FOR RF DEVICE:
FCC ID: A8W-4020528
This device complies with part 15 of the FCC Rules
and RSS-210 of IC Rules. Operation is subject to
the following two conditions: (1) This device may
not cause harmful interference, and (2) this device
must accept any interference received, including
interference that may cause undesired operation of
the device.
50°F
54°F 70°F
72°F

= Supply air temperature
after the rotor.
= Function of keys up and down
for view mode 1, 2 and 4.
= Indicates Boost is active.
= Pressure compensation is active.
= CO2compensation is active.
= RH compensation is active..
CO2
= Indicates that the rotor is operating.
+
= heat recovery
-= cooling recovery
= Temperature efficiency.
= Symbol indicates that
the heating coil is on.
= Symbol indicates that
the cooling coil is on.
= Week timer is active.
= Summer cooling is active.
= Outside temperature.
= Exhaust air temperature.
= Supply air temperature.
= Extract air temperature.
= CO2compensation is active.
= Function of A-key.
Press A-key to regulate ”boost”
of supply & exhaust air flow
= Function of B-key.
Press B-key to turn off
pressure compensation.
= Function of B-key.
Press B-key to choose
”Away” on or off.
= Function of keys up and down
for view mode 1, 3 and 4.
= Alarm
= Indicates Boost is active.
= Indicates Away is active.
= Pressure compensation is active.
= RH compensation is active.
C
CO2
In order to go
view mode 2
or 4 press
or .
In order to
return to view
mode 1, press .
In order to go
view mode 3
or 4 press
or .
In order to
return to view
mode 1, press .
VIEW MODE 3
= Display weekday and time.
= Indicates that Summer
cooling is active.
= Indicates that week timer
is active.
= Room temperature.
Sensor placed in room.
= Relative air humidity in per cent.
= Carbon dioxide level in PPM
(part per million).
SYMBOLS THAT CAN BE DISPLAYED IN VIEW MODE 3:
Press key to choose Boost off/on of the
supply & exhaust air flow for a specific time
(time and fan speed settings during the boost
is made in the Service menu ”Boost” page 69).
When the ”plus”+
+
symbol is displayed in the
right corner, the boost is activated.
...
VIEW MODE 1
In order to go
view mode 2, 3
or 4 press
or .
In order to
return to view
mode 1, press .
= Indicates that the rotor is operating.
+
+
= heat recovery
-= cooling recovery
= Fan speed. Choose from min,
standard, medium, max.
= Symbol indicates that
the heating coil is on.
= Summer cooling is active.
= Week timer is active.
= Function of A-key.
Press A-key to regulate ”boost”
of supply & exhaust air flow.
= Function of B-key.
Press B-key to turn off
pressure compensation.
VIEW MODE 2
SYMBOLS THAT CAN BE DISPLAYED IN VIEW MODE 1:
SYMBOLS THAT CAN BE DISPLAYED IN VIEW MODE 2:
= Function of B-key.
Press B-key to choose
”Away” on or off.
= Symbol indicates that
the cooling coil is on.
= Function of keys up and down
for view mode 2, 3 and 4.
= Alarm
= Indicates Boost is active.
= Indicates Away is active.
= Pressure compensation is active.
IN VIEW MODE 1 AND 2 BOOST OFF/ON AND AWAY OFF/ON CAN BE CHOOSEN.
Press key to choose Away off/on.
When the symbol ”suitcase” is
displayed in the right corner, the away
mode is activated, i.e. the fan speed is
minimum.
11
5
50°F
54°F 70°F
72°F
50°F
54°F 70°F
72°F
72°F 68°F
68°F

12
In this menu desired fan speed is chosen. You can choose from 4 speeds: Min, Standard, Medium and Max.
Normal operation should be done in standard mode
Press in order to go forward from the Main Menu. Press again and then in order to choose
the desired fan speed. Confirm with .
In this menu desired temperature is chosen (supply air, extract air or room temperature) depending on what
kind of regulation that is choosed, see page 20.
Press in order to go forward from the Main Menu. Press again and then in order to choose the
desired temperature (15-30°C/59-86°F). Confirm with .
In this menu Boost On/Off is chosen. The time has the factory setting of 30 min. and fan speed Medium.
To adjust the fan speed and time, see page 17.
Boost is activated/disable (On/Off) with the key.
”FAN SPEED” MENU (Only for HERU®AC)
”TEMPERATURE” MENU
”BOOST” MENU
In order to go forward in the menu from the View mode to the Main Menu press .
In the Main Menu is used to select the desired menu, after the choice is made with .
The procedure is the same in the submenu. In order to return to the previous page press .
”MAIN MENU”
The Boost function can also be activated with an external switch with double pressure or timer.
See wiring diagram page 40-41. The Boost is On as long as the breaker is closed.
Made settings is overridden if Week Timer is activated.
Made settings is overridden if Week Timer is activated.
O
Off
70°F
70°F

When in normal operation the unit runs with the fan speed that was choosen in the “Fan Speed” menu and
the temperature that was choosen in the “Temperature” menu. A departure from these programmed values that
you periodically want to recall is done in this menu. For example if you want to have a lower flow/temperature
during the daytime when nobody is at home then there is the possibility to adjust this here.
Week timer. If end time is the same or less than start time the program will end the following day.
Press in order to go forward from the Main Menu.
Press again and then in order to choose off/on of the week timer. Confirm with .
Press to choose/adjust the desired program. There are 5 programs for the adjustment of the fan speed
and temperature available. Press to choose a program.
Press in order to go forward to choose a weekday, start time, end time, fan speed and temperature.
Use the keys to choose the settings of weekday, start time, and end time, fan speed (Min, Standard,
Medium, Max, Standby*) and temperature (15-30°C/59-86°F).
Overpressure is a special feature were you can pressure compensate when supplementary
heating using an open fire or stove. The exhaust air fan then drops to a lower speed
during set time.
In this menu Overpressure On/Off is chosen. The time has the factory setting of 15 min.
To adjust the time, see page 17.
Overpressure is activated/disable (On/Off) with the key.
13
“OVERPRESSURE” MENU
“WEEK TIMER” MENU
Cont.
Cont. next line.
When pressure compensate is
activated the symbol ”Away”
will be change to the symbol
”Overpressure” in View
mode 1 and 2.
Than press directly in the
View mode to turn off Over-
pressure.
Cont
Cont. next line.
O
Off
* Standby mode must only be used if a motorized damper is mounted on the exhaust and fresh air duct, in order to
protect from condensation inside the unit. The dampers should be connected to the control board "Duct valve".
Power On/Off
N.B! The activated Week Timer over-
rides the manuel settings of fan speed
and temperature.
Program with the lowest index has
priority when two programs overlap
each other. E.g. Program 1 has priority
over program 2 when overlapped.
70°F 70°F
70°F

This meny displayes triggered alarms.
View mode 1 shows alarm and
View mode 2 shows what kind of alarm.
Press in order to go forward from the Main Menu and to view status.
When alerting a dialogue box for the alarm is shown in the Main Menu and the display will flash.
“View alarms” is shown and the possibility for equalization is given.
Press to see the cause of alarm in Submenu. Control the cause and remedy the alarm.
Press to ”Clear all” and than .
Current alarm is viewed. When "Sensor open" and "Sensor shorted" press "Show"
to view which sensor GT 1-8 is alerting.
See Control diagram on page 8.
In order to return to the previous pages press .
14
“ALARMS” MENU (Displayed only if an alarm is triggered)
In the ”Power On/Off” Menu you have the possibility of turning off the unit via the wireless control unit.
NB! The unit must be currentless during service and maintenance.
Press in order to go forward from the Main Menu. Press in order to choose on/off of the unit.
When "On" is displayed in the center of the display, the unit is on. When "Off" is displayed the unit is off.
“POWER ON/OFF” MENU
Alarms is shown for:
• ”Fire alarm” • ”Sensor open” • ”Sensor shorted” • ”Overheating”• ”Freeze alarm” • ”Supply temp. low”
• ”Rotor temp. low” • ”Rotor failure” • ”Filter” • ”Filter timer” • ”Supply fan alarm” • ”Exhaust fan alarm”
!
!Filtertimer
Reset
To avoid condensation in the unit during the cold season
the unit should not be turned off for a longer period.
Power On/Off
Settings
Power On/Off
Power On/Off
When alarm for Filter timer is triggered it can be equalized with Reset.
A reminder to change filter comes in a seven-day interval.
To restart the timer see ”Service Menu Alarm” page 18.
50°F
54°F 70°F
72°F

“SETTINGS” MENU
In this menu settings are made for weekday, time what language and unit system.
Press in order to go forward from the Main Menu. Press again and then in order to choose weekday.
Press again and then in order to enter the time.
Press in order to enter a language. Press and then in order to choose a language. Confirm with .
5 languages are available: Swedish, Finnish, French, English and Spanish.
Press in order to enter a unit system. Press and then in order to choose. Confirm with .
Choose from: Metric and Imperial.
15
W
Week timer
Power On/Off
U
Unit system
Imperial
Unit system
Imperial
THE “SERVICE MENU”
In this menu a password is required in order to make adjustments. The password is 1199 and it can not be changed.
Press in order to go forward from the Main Menu.
The password is entered with the keys and every number is confirmed with .
After the password 1199 to the Service Menu the question “Are you sure?” will be displayed.
Press for “No” or for “Yes”.
To go further to the different functions in the ”Service menu” press or .
A
Are you sure?
No Yes
Week timer
Power On/Off

SERVICE MENU: “AC FAN SETUP”:
When adjusting the unit, the speed is set to
standard and functions that may affect the
fan speed, such as “Away” and “Boost”,
is inactivated.
SERVICE MENU: “FILTER MEASUREMENT”
If filter switches are installed and activated, weekday and time is set when the unit should boost
to measure the pressure drop in supply air filter GP1 and exhaust air filter GP2.
If no filter switches or pressure sensor are selected this is displayed:
ServicemenyServicemeny
FiltermätningFiltermätning
EC-motor setupEC-motor setup
Display kontrastDisplay kontrast
Är du säker?
Bör endast ändras
av installatör!
Standard (%)
Tilluft: 60%
Frånluft: 70%
Minimum
Min: 20%
EC-motor setupEC-motor setup
StandardStandard
Min
Medium
Medium Avbryt Ok
Standard
(konst.tr.)
Till: 90Pa (45%)
Från: 110Pa (50%)
Till konst.tr.
EC-motor setup
Standard
Min
Medium
Minimum
Min: 20%
Standard (%)
Tilluft: 60%
Frånluft: 70%
Standard (%)
Tilluft: 60%
Frånluft: 70%
Pressure inputs
Filter measurement
EC fan setup
Display contrast
Are you sure?
Should not be
changed by user!
Standard (%)
Sup: 60%
Exh: 70%
Minimum
Min: 20%
EC fan setup
Standard
Min
Medium Cancel Ok
Standard
(CPC)
Sup: 90Pa (45%)
Exh: 110Pa (50%)
Go to CPC
EC fan setup
Standard
Min
Medium
Minimum
Min: 20%
Standard (%)
Sup: 60%
Exh: 70%
Standard (%)
Sup: 60%
Exh: 70%
-
--Fan speed--
Standard
Service menu
Service menu
Filter measurement
AC fan setup
Display contrast
SERVICE MENU: “PRESSURE INPUTS”
If filter switches are installed these can be activated in this meu.
If ”None” is set, the filter measurement is automatically deactivated.
Pressure sensors can not be used for HERU®AC.
16

SERVICE MENU: “MAX TEMPERATURE”:
Setting the Max temperature. This gives a max´ temperature of electrical heater, supply air limit and
temperature in the week timer. The factory setting is 30°C/86°F. Possible to change the max temperature to
40°C/104°F.
Press in order to go forward from the Service Menu. Press again and then
in order to choose the desired Max temperatur (15-40°C/59-104°F).
SERVICE MENU: “DISPLAY CONTRAST”
Display contrast setting. The contrast can be set between 0-63.
17
SERVICE MENU: “BOOST”:
Time settings for Boost and Fan speed. Boost means that during a limited time the air flow increases, which can
be good for example at larger gatherings.
This boost can then be activated at the View mode 1 and 2, and in the Main Menu “Boost”.
Press in order to go forward from the Main Menu. Press again and then in order to choose
the desired duration. (10-240 min. with the interval of 10 min.)
Press in order to confirm and go forward to fan speed.
Choose the desired fan speed with (medium or max) and confirm with .
Boost is activated/disable (on/off) with the key.
E
EC fan setup
Display contrast
SERVICE MENU: “OVERPRESSURE”
Time settings for Overpressure. Overpressure compensate is a special feature when supplementary heating
using an open fire or stove (the exhaust air fan drops to a lower speed during a specific time).
Press in order to go forward from the Service Menu. Press again and then
in order to choose the desired duration (5-60 min.).
D
Display contrast
Boost
Max temperature
B
Boost
Overpressure
Max temperature
Alarm
Max temperature
86°F
M
Max temperatur e
86°F
AC fan setup

SERVICE MENU: “ALARM”
In this menu alarm limits is set for Filter timer, Low temperature and setting for Fire sensor, Automatic reset
and Alarm indication to the alarm port.
”Filter timer” can be set from ”Off” to ”6-12 months” and generates alarm for filter change.
Filter timer can not be used in combination with another filter measurement, see page 16.
We recommend filter change at least once a year.
To restart the filter timer press “Reset” with the -key.
Alarm limits for ”Low temperature”.
Alarm limit A: (+2 to +10ºC/+36° to +50°F) but must be lower than ”Alarm limit B”).
Alarm for low rotor temperature is displayed when the temperature is lower than set value. Normally nothing
needs to be done. If “Rotor Alarm” appear at the same time as “Rotor temp. Low” the unit is stopped.
Alarm limit B: Supply air flow is reduced with one step when the temperature in supply air duct (GT7) is
lower than set value, the temperature efficiency will increase (the temperature can be change from
+5 to +12ºC/+41° to +54°F but have to be higher than ”Alarm limit A”).
If the unit operating at Min. speed the extract air increases one step.
In menu ”Fire sensor” type of installed fire sensor is set.
Choose ”Normally open” NO or ”Normally closed” NC depending on
the type of smoke detector.
"Automatic reset" allows a automatic restart of the unit after
the fire alarm is restored to normal (NO, NC).
In the menu ”Alarm indication”, the alarm can be associated to the alarm
port on the control board (NO,NC).
If all is choosed this is indicated by "All". If only one or more is selected
this is indicated by "Selected".
A
Auto.reset: Off Aut. reset: Off
N
Not installed
Auto.reset: On
A
Alarm indication
None
Alarm indication
Fire alarm
Sensor open
Sensor shorted
A
Alarm indication
Fire alarm
Sensor open
Sensor shorted

A
Alarm indication
Overheating
Freese alarm
Supply temp. low
A
Alarm indication
Rotor temp. low
Fan failure
Rotor failure
A
Alarm indication
Rotor failure
Filter
Filter timer
A
Alarm indication
All
A
Alarm indication
Selected
R
Reset
Overpressure
Max temperature
36°F
54°F
36°F
54°F
36°F
54°F
18

SERVICE MENU: “RH” Relative air humidity in percent
In this menu settings are made for regulation with installed RH sensor.
Press again and then in order to choose the ”Limit value” of boost (50%-100%).
Press again and then in order to choose Interval (1-10 min.).
At levels above the limit value the fan speed will increase one step according to the set Interval value.
Current RH value is displayed in View mode 3, see page 11.
19
I
Interval: 5 min. Interval: 5 min.
Interval: 5 min.
SERVICE MENU: “CO2” Carbon dioxide level in PPM (part per million).
In this menu settings are made for regulation with installed CO2 sensor.
Press again and then in order to choose the Limit value (500-1400 PPM).
Press again and then in order to choose Interval (1-10 min.).
At levels above the limit value the fan speed will increase one step according to the set Interval value.
Current CO2 value is displayed in View mode 3, see page 11.
I
Interval: 5 min. Interval: 5 min.
Interval: 5 min.
SERVICE MENU: “HEATER”
In this menu type of Heater is chosen to be activated.
If ”Afterblow” is activated and the heater has operated, the supply air fan continues to run for at least two min-
utes after the heater is turned off.
If a heating coil is used a freeze protection sensor (GT5) must be installed, and a damper ST1 must be
mounted in the fresh air duct. The GT7 must be mounted after the Heater.
Press again and then in order to choose On or Off.
A
Afterblow: Off
Afterblow: Off Afterblow: Off
Afterblow: Off
Cont. next line.
Cont.

SERVICE MENU: “REGULATION MODE”
3 different types of regulation modes can be used.
• At a constant supply air regulation the temperature sensor (GT7) is placed in the supply air duct and
a constant incoming air temperature is obtained.
• At room regulation a sensor (GT8) is placed in the room and a sensor (GT7) in the supply air duct
(minimum/maximum limitation) and a constant room temperature is obtained (suitable when
a cooling coil is installed).
• The extract air regulation works in a similar way as the room regulation with the difference being that
the temperature is measured in the extract air duct.
Press again and then in order to choose Supply reg., Extract reg. or Room reg.
SERVICE MENU: “MODBUS”
Menu "Modbus" appears only in version + wireless control unit.
Version + wireless control unit activates the Modbus port on the control board and the ability to communicate
via RS485. For this you need complete Modbus index that you can download from www.ostberg.com.
ID and baud rate must match the client settings.
M
Modbus Id
1
9600 Baud
Modbus Id
1
9600 Baud
Modbus Id
1
9600 Baud
Device name Device name
Done Clear
1/128
Modbus
Extract reg.
Supply limits
Regulation mode
Modbus
Freeze protection
20
SERVICE MENU: “SUPPLY LIMITS”
In this menu the upper and lower limit value for the supply air temperature at room or extract air regulation is set.
Press again and then in order to choose a minimum limit value (15-19°C/59-66°F).
Press again and then in order to choose a maximum limit value (20-30°C/68-86°F).
SERVICE MENU: “COOLER”
In this menu a cooling coil can be activated if installed.
Press again and then in order to choose On or Off.
8
86°F 86°F
63°F
63°F
79°F
63°F