Nibe ERS 20-250 User guide

IHB EN 2001-1
531798
INSTALLER MANUAL
Ventilation heat exchanger
NIBE ERS 20-250
LEK

41 Important information
4Safety information
4Serial number
4Recovery
5Inspection of the installation
62 Delivery and handling
6Transport and storage
6Assembly
6Supplied components
7Removing the covers
83 The ventilation heat exchanger design
9Pipe connections
9Sensors etc.
9Electrical components
9Ventilation
9Miscellaneous
104 Pipe and ventilation connections
10Mounting
10Condensation water drain
11General ventilation connections
12Ventilation flow
12Adjusting ventilation
12Dimension and ventilation connections
12Preheating outdoor air
135 Electrical connection
13Connecting to main product
15Outside air sensor
166 Commissioning and adjusting
16Preparations
16Filling
16Start-up and inspection
177 Program settings
17Start guide
17Menu system
188 Disturbances in comfort
18Troubleshooting
199 Accessories
2010 Technical data
20Dimensions ERS 20
21Technical specifications
22Energy labelling
23Electrical circuit diagram
27Contact information
3Table of ContentsNIBE ERS 20-250
Table of Contents

Safety information
This manual describes installation and service proced-
ures for implementation by specialists.
The manual must be left with the customer.
This appliance can be used by children
aged from 8 years and above and persons
with reduced physical, sensory or mental
capabilities or lack of experience and
knowledge if they have been given super-
vision or instruction concerning use of the
appliance in a safe way and understand
the hazards involved. Children shall not
play with the appliance. Cleaning and user
maintenance shall not be made by children
without supervision.
Rights to make any design or technical
modifications are reserved.
©NIBE 2020.
SYMBOLS
NOTE
This symbol indicates danger to person or ma-
chine .
Caution
This symbol indicates important information
about what you should consider when installing
or servicing the installation.
TIP
This symbol indicates tips on how to facilitate
using the product.
MARKING
The CE mark is obligatory for most products sold
in the EU, regardless of where they are made.
CE
Classification of enclosure of electro-technical
equipment.
IP21
Serial number
The serial number can be found at the top left.
LEK
Serial number
LEK
Caution
You need the product's serial number for servi-
cing and support.
Recovery
Leave the disposal of the packaging to the in-
staller who installed the product or to special
waste stations.
When disposing of the product, its constituent
materials and components, e.g. compressors,
fans, circulation pumps and circuit boards, must be dis-
posed of at a special waste station or dealer who
provides this type of service.
To access the separate components, refer to the section
that shows the construction of the product. No special
tools are required for access.
Improper disposal of the product by the user results in
administrative penalties in accordance with current le-
gislation.
NIBE ERS 20-250Chapter 1 | Important information4
1 Important information

Inspection of the installation
Current regulations require the heating installation to be inspected before it is commissioned. The inspection must
be carried out by a suitably qualified person. In addition, fill in the page for the installation data in the User Manual.
DateSigna-
ture
NotesDescription
✔
Electricity (page 13)
Connections
Main voltage
Fuses property
Earth circuit-breaker
5Chapter 1 | Important informationNIBE ERS 20-250

Transport and storage
ERS 20 should be transported and stored in the dry.
Assembly
ERS 20 is installed in the roof using the enclosed roof
brackets. Noise from the fans can be transmitted to the
brackets.
• Install ERS 20 on an outside wall, ideally in a room
where noise does not matter, in order to eliminate
noise problems. If this is not possible, avoid placing
it against a wall behind a bedroom or other room
where noise may be a problem.
• Wherever the unit is located, walls to sound sensitive
rooms should be fitted with sound insulation.
• Condensation comes from the ventilation heat ex-
changer. A condensation outlet with a water seal must
be installed and routed to an internal drain.
• The ventilation heat exchanger’s installation area
should always have a temperature of at least 10 °C
and max. 35 °C.
INSTALLATION AREA
Leave a free space of 1,000 mm in front of the distribu-
tion box and 200 mm in front of the other sides. Because
servicing is carried out from underneath, free space of
1,600 mm is recommended below the unit.
1000
200 200
200
Supplied components
2 x roof brackets
NIBE ERS 20-250Chapter 2 | Delivery and handling6
2 Delivery and handling

Removing the covers
1. Slacken off the four screws holding the side panel.
Move the panel out and downwards.
LEK
2. Unscrew all the screws holding the bottom panel.
LEK
3. Lift the bottom panel down.
LEK
7Chapter 2 | Delivery and handlingNIBE ERS 20-250

LEK
LEK
GQ3
XL32 XL34
XL33 XL31AA5
GQ2 EP26
XL40
HQ10HQ11
UB1
QN37
W1W2PF1
BT22BT20BT23BT21BL2
NIBE ERS 20-250Chapter 3 | The ventilation heat exchanger design8
3 The ventilation heat
exchanger design

Pipe connections
Ventilation connection, exhaust airXL31
Ventilation connection, extract airXL32
Ventilation connection, supply airXL33
Ventilation connection, outdoor airXL34
Condensation water drainXL40
Sensors etc.
Level monitorBL2
Temperature sensor, exhaust airBT20
Temperature sensor, extract airBT21
Temperature sensor, supply airBT22
Temperature sensor, outdoor airBT23
Electrical components
Accessory cardAA5
Cable glandUB1
Cord with connection plugW101
Communication cableW102
Ventilation
Heat exchangerEP26
Exhaust air fanGQ2
Supply air fanGQ3
Exhaust air filterHQ10
Supply air filterHQ11
Bypass damperQN37
Miscellaneous
Type platePF1
Condensation water troughWM5
Designations according to standard EN 81346-2.
9Chapter 3 | The ventilation heat exchanger designNIBE ERS 20-250

Mounting
When installing on a wooden roof, a vibration damper
is recommended to prevent vibration being transferred.
1. Install the two enclosed roof mountings in the roof.
1205
2. Move ERS 20 into position.
LEK
3. Secure ERS 20 with screws.
Condensation water
drain
ERS 20 can produce several litres of condensation water
per day. It is therefore important for the condensation
outlet to be correctly executed and for the ventilation
heat exchanger to be installed horizontally.
Check that the water seal is airtight and firmly in posi-
tion. The connection must be made so that the user can
check and top up the water seal, without opening ERS
20.
CLEANING THE CONDENSATION WATER
DRAIN
Condensation forms when ERS 20 is working. This
condensation is led off and collected in the condensation
water drain. Apart from water, a certain amount of dust
and particles also collect there.
Check regularly that the condensation water drain and
any floor drains are not blocked; water must be able to
run through freely. Clean, if necessary.
NOTE
During operation, negative pressure arises in
the ventilation heat exchanger, which means
that a water column of at least 100 mm must
be guaranteed in the water seal.
NIBE ERS 20-250Chapter 4 | Pipe and ventilation connections10
4 Pipe and ventilation
connections

100
General ventilation
connections
• Ventilation installation must be carried out in accord-
ance with current norms and directives.
• Provision must be made for inspection and cleaning
of the duct.
• The air duct system must be a minimum of air tight-
ness class B.
• To prevent fan noise being transferred to the ventila-
tion devices, silencers should be installed in the duct
system. In the event of ventilation devices in noise-
sensitive rooms, silencers must be installed.
• The extract air and outdoor air ducts are insulated us-
ing diffusion-proof material (at least PE30 or equival-
ent) along their entire lengths.
• Ensure that the condensation insulation is fully sealed
at any joints and/or at lead-in nipples, silencers, roof
cowls or similar.
• The air must be routed to the outdoor air duct through
an outer wall grille in the facade. The outer wall grille
must be installed so that it is protected from the
weather and must be designed so that no rainwater
and/or snow can penetrate the facade or follow the
air into the duct.
• When positioning the outdoor air and extract air
hood/grille, bear in mind that the two air flows must
not short circuit to prevent the extract air from being
drawn into ERS 20 again.
• A duct in a masonry chimney stack must not be used
for extract air or outdoor air.
NOTE
To ensure a sealed connection to ERS 20,
nipples must be used when connecting the air
ducts.
EXHAUST AIR DUCT /KITCHEN FAN
Exhaust air duct (kitchen fan) must not be connected to
ERS 20.
To prevent food vapour being transferred to ERS 20 the
distance between the kitchen fan and the exhaust air
device must be considered. The distance should not be
less than 1.5 m, but this can vary between different in-
stallations.
Always use a kitchen fan when cooking.
11Chapter 4 | Pipe and ventilation connectionsNIBE ERS 20-250

Ventilation flow
Connect ERS 20 so that all the exhaust air, except kit-
chen duct air (kitchen fan), passes through the heat ex-
changer (EP26) in the product.
The ventilation flow must comply with the applicable
national standards.
The supply air flow must be lower than the exhaust air
flow to prevent over pressure in the house.
Set the ventilation capacity in the main product’s menu
system (menu 5.1.5).
Adjusting ventilation
To obtain the necessary air exchange in every room of
the house, the exhaust air valve and the supply air inlet
as well as the fans in the ventilation heat exchanger
must be correctly positioned and adjusted.
Immediately after installation adjust the ventilation so
that it is set according to the projected value of the
house.
Incorrect adjustment of the ventilation may lead to re-
duced installation efficiency and thus poorer operating
economy, and may cause moisture damage in the
building
Dimension and
ventilation
connections
Ø125
110125
255130
120120
Ø125
LEK
Exhaust air
Supply air
Outdoor air
Extract air
Preheating outdoor air
If the extract air temperature is too low, the supply air
fan slows down to prevent the condensation water in
the heat exchanger from freezing.
To prevent this from happening too often in areas with
colder climates, an electrical air heater EAH (EB17) and
an outdoor air sensor (BT23) should be installed in the
outdoor air duct as illustrated. EAH heats the incoming
outdoor air so that the extract air temperature does not
fall to the stated level.
See the Installer Manual for EAH for more information.
EB17BT23
ERS 20
NIBE ERS 20-250Chapter 4 | Pipe and ventilation connections12

NOTE
All electrical connections must be carried out
by an authorised electrician.
Electrical installation and wiring must
be carried out in accordance with the
stipulations in force.
ERS 20 must not be powered during installa-
tion.
NOTE
If the supply cable is damaged, only
NIBE, its service representative or
similar authorised person may replace
it to prevent any danger and damage.
NOTE
To prevent interference, sensor cables to ex-
ternal connections must not be laid close to
high voltage cables.
For electrical wiring diagram, see page 23.
Connecting to main
product
If several accessories are to be connected, or are already
connected, the following cards must be connected in
series with the previous card.
Use cable type LiYY, EKKX or similar.
ON
12345678
-X9
-X2
24 20212223 1516171819 1011121314 56789 1
1
N
L
PE
PE
1
2
3
4
5
6
7
8
2
3
4
5
6
7
8
9
234
-X8
-X4
-X10
-X1
AA5-S2
AA5-X4
13Chapter 5 | Electrical connectionNIBE ERS 20-250
5 Electrical connection

S-SERIES
The communication cable (W102) in ERS 20 must be
connected to the main product.
B A GND +12V
AA2-X30
1 2 3 4
AA5-X4
1
2
3
4
5
6
7
8
A
B
GND
Main product
ERS 20
If more ERS 20 are to be installed, they must be connec-
ted in series as illustrated:
B A GND
+12V
AA2-X30
1 2 3 4
AA5-X4
1
2
3
4
5
6
7
8
A
B
GND
A
B
GND
AA5-X4
1
2
3
4
5
6
7
8
A
B
GND
A
B
GND
ERS 20 1
Main product
ERS 20 2
F-SERIES
The communication cable (W102) in ERS 20 must be
connected to the main product.
15
A (vit)
B (brun)
GND (grön)
A (vit)
B (brun)
GND (grön)
14
13
AA3-X4
1
2
3
4
5
6
7
8
AA5-X4
Main product
ERS 20
A (white)
B (brown)
GND (green)
A (white)
B (brown)
GND (green)
If more accessories are installed, they must be connec-
ted in series, as illustrated:
1
2
3
4
5
6
7
8
AA5-X4
15
A (vit)
B (brun)
GND (grön)
A (vit)
B (brun)
GND (grön)
A
B
GND
A
B
GND
14
13
AA3-X4
1
2
3
4
5
6
7
8
AA5-X4
Main product
Accessories 1
ERS 20
A (white)
B (brown)
GND (green)
A (white)
B (brown)
GND (green)
TIP
See the main product’s Installer Manual for the
placing of the input board.
NIBE ERS 20-250Chapter 5 | Electrical connection14

The DIP switch (AA5-S2) must be set as follows.
ON
1 2 3 4 5 6 7 8
ERS 20 no. 2
ON
1 2 3 4 5 6 7 8
ERS 20 no. 1
ON
1 2 3 4 5 6 7 8
ERS 20 no. 4
ON
1 2 3 4 5 6 7 8
ERS 20 no. 3
Outside air sensor
When installing with an electrical preheater (EAH), dis-
connect the outdoor air sensor (BT23) in ERS 20.
The enclosed outdoor air sensor EAH is placed in the
outdoor air duct and connected to the accessory board
(AA5) according to the Installer Manual for EAH.
15Chapter 5 | Electrical connectionNIBE ERS 20-250

Preparations
• Check the miniature circuit-breaker (FA1) in the main
product. It may have tripped during transportation.
• Check that the air filters are clean, they can become
dirty after installation.
Filling
• Check that there is water in the water seal, fill if ne-
cessary.
Start-up and
inspection
SETTING THE VENTILATION
The ventilation must be set according to applicable
standards. The supply air flow is adjusted to guarantee
a negative pressure. The settings are made in menu
7.1.4 for the S-series and in menu 5.1.5 and 5.1.6 for
the F-series.
Even if ventilation is roughly set at installation it is im-
portant that a ventilation adjustment is ordered and
permitted.
Caution
An incorrectly set ventilation flow can damage
the house and may also increase energy con-
sumption.
NOTE
Order a ventilation adjustment to complete the
setting.
Ventilation capacity
00 10 20 30 40 50 60 70 80
100
50
150
250
350
200
300
400
Tillg ngligt tryck
(Pa)
Flöde
(l/s)
30%
100%
80%
60%
40%
50%
70%
Available pressure
Airflow
Fan output1
0100 20 30 40 50 60 70
10
20
30
40
50
60
70
Effekt
(W)
Fl de
(l/s)
30%
100%
80%
60%
50%
70%
40%
Output
Airflow
1The diagram shows the power consumption per fan.
Dry temperature efficiency according to EN 308
78 0 25 50 75 100 125 150 (l/s)
0 100 15050 200 300250 350 400 500450 550 (m3/h)
80
82
84
86
88
90
92
94
Temperatur
( C)
Luftflöde
Temperature efficiency
Airflow
(m³/h)
NIBE ERS 20-250Chapter 6 | Commissioning and adjusting16
6 Commissioning and adjusting

Program setting of ERS 20 can be performed via the
start guide or directly in the menu system in the main
product.
Caution
See the documentation for the main product.
Start guide
The start guide appears at the first start-up after the
heat pump installation, but can also be found in menu
7.7 in the S-series and menu 5.7 in the F-Series
Menu system
S-SERIES
If you do not make all settings via the start guide or need
to change any of the settings, this can be done in the
menu system.
Menu 7.2.1. - Add/remove accessories
Activating/deactivating of accessories.
Select “exhaust/supply air module 1-4"”.
F-SERIES
If you do not make all settings via the start guide or need
to change any of the settings, this can be done in the
menu system.
Menu 5.2.4 -system settings
Activating/deactivating of accessories.
Activate: "exhaust/supply air module".
Menu 5.3.12 - exhaust/supply air module
Settings specific to ERS 20.
"Lowest extract air temp.": Set the minimum extract air
temperature to prevent the heat exchanger freezing.
The supply air fan speed reduces if the extract air tem-
perature at (BT21) is lower than the set value.
"Bypass at excess temperature": If a room sensor is in-
stalled, set the over-temperature at which the bypass
damper (QN37) must open here.
"Bypass during heating": Set here if you want to allow
the bypass damper (QN37) to open during heat produc-
tion as well.
"Months btwn filter alarms": Set how often the filter
alarm must be displayed.
"Action level monitor": If level monitor is selected, the
product issues an alarm and the fan stops when the in-
put is closed. When blocking is selected, text in operat-
ing info shows that the input is closed. The fans stop
until the input is open.
TIP
When ERS 20 is activated, the other ventilation
menus will also light up.
17Chapter 7 | Program settingsNIBE ERS 20-250
7 Program settings

In most cases, the main product notes a malfunction (a
malfunction can lead to disturbance in comfort) and in-
dicates this with alarms and shows action instructions
in the display.
Troubleshooting
If the operational interference is not shown in the display
the following tips can be used:
BASIC ACTIONS
Start by checking the following possible fault sources:
• That the main product is running and that the supply
cable to ERS 20 is connected.
• Group and main fuses of the accommodation.
• The property's earth circuit breaker.
• The main product's fuses/temperature limiter.
HIGH OR LOW ROOM TEMPERATURE
• See Installer Manual for the main product.
LOW OR A LACK OF VENTILATION
• Level monitor (BL2) tripped.
– Checking the condensation water drain and water
seal.
• Filter blocked.
– Clean or replace the filter.
• The ventilation is not adjusted.
– Order/implement ventilation adjustment.
•Closed, too much choke or blocked ventilation device.
– Check and clean the exhaust air devices.
• Fan speed in reduced mode.
–Go to the main product’s menu 1.2.1 for the S-series
and 1.2 for the F-Series and select "normal".
• External switch for changing the fan speed activated.
– Check any external switches.
• Fan running slow because of low incoming outdoor
air temperature.
– Check the function and settings for the electrical air
heater (EAH) if installed.
HIGH OR DISTRACTING VENTILATION
• Filter blocked.
– Clean or replace the filter.
• The ventilation is not adjusted.
– Order/implement ventilation adjustment.
•Closed, too much choke or blocked ventilation device.
– Check and clean the exhaust air devices.
• Fan speed in forced mode.
–Go to the main product’s menu 1.2.1 for the S-series
and 1.2 for the F-Series and select "normal".
• External switch for changing the fan speed activated.
– Check any external switches.
• Silencers not correctly installed.
– Check the silencers.
NIBE ERS 20-250Chapter 8 | Disturbances in comfort18
8 Disturbances in comfort

Some accessories manufactured before 2019 may need
to have their circuit board updated in order to be com-
patible with ERS 20. For more information, see the In-
staller Manual for the relevant accessory.
ELECTRICAL AIR HEATER EAH 20
In cold weather, EAH 20-900 heats the incoming outdoor
air slightly to prevent the condensation in ERS 20 from
freezing. Used mainly in colder climates.
Part no. 067 604
19Chapter 9 | AccessoriesNIBE ERS 20-250
9 Accessories

Dimensions ERS 20
1271 (1367 inkl takfäste)
Ø125
673
110125
1202
255130
120120
241
Ø125
Ø15
1271 (1367 incl. roof mounting)
NIBE ERS 20-250Chapter 10 | Technical data20
10 Technical data