Vaillant uniSTOR VIH GB 3 BES Series User manual

Installation and maintenance instructions
uniSTOR
VIH GB .../3 BES
GB, IE
Publisher/manufacturer
Vaillant GmbH
Berghauser Str. 40 D-42859 Remscheid
Tel. [phone] Fax [phone]
[email protected] www.vaillant.de

Contents
2Installation and maintenance instructions uniSTOR 0020221297_05
Contents
1 Safety .................................................................... 3
1.1 Action-related warnings ......................................... 3
1.2 Risk caused by inadequate qualifications.............. 3
1.3 Intended use .......................................................... 3
1.4 General safety information .................................... 3
1.5 Regulations (directives, laws, standards) .............. 4
2 Notes on the documentation .............................. 5
2.1 Observing other applicable documents ................. 5
2.2 Storing documents................................................. 5
2.3 Validity of the instructions...................................... 5
2.4 Benchmark............................................................. 5
3 Product description............................................. 5
3.1 Serial number ........................................................ 5
3.2 Information on the identification plate.................... 5
3.3 CE marking ............................................................ 5
3.4 Hot Water Association ........................................... 6
4 Set-up.................................................................... 6
4.1 Observing the requirements for the product's
installation site ....................................................... 6
4.2 Transport ............................................................... 6
4.3 Unpacking the product........................................... 7
4.4 Checking the scope of delivery.............................. 7
4.5 Product dimensions ............................................... 7
5 Installation............................................................ 8
5.1 Setting up the unit horizontally .............................. 8
5.2 Hydraulic connection ............................................. 8
5.3 Electrical installation ............................................ 11
6 Start-up ............................................................... 13
6.1 Setting the immersion heater thermostat............. 13
6.2 Cold water inlet pressure..................................... 14
6.3 Filling and purging the product ............................ 14
6.4 Filling and purging the heating circuit .................. 14
7 Handing the product over to the end user ...... 14
8 Troubleshooting ................................................ 14
8.1 Detecting and eliminating faults........................... 14
8.2 Procuring spare parts .......................................... 14
9 Inspection and maintenance ............................ 14
9.1 Observing inspection and maintenance
intervals ............................................................... 14
9.2 Draining the product ............................................ 15
9.3 Checking the safety group's expansion relief
valve and the cylinder's expansion relief valve .... 15
9.4 Checking the pre-charge pressure of the
expansion vessel ................................................. 15
10 Decommissioning the product......................... 15
11 Customer service............................................... 15
Appendix ............................................................................ 16
A Detecting and eliminating faults ...................... 16
B Inspection and maintenance work –
Overview............................................................. 16
C Technical data.................................................... 16
D Commissioning Checklist................................. 19
Index ................................................................................... 22

Safety 1
0020221297_05 uniSTOR Installation and maintenance instructions 3
1 Safety
1.1 Action-related warnings
Classification of action-related warnings
The action-related warnings are classified in
accordance with the severity of the possible
danger using the following warning signs and
signal words:
Warning symbols and signal words
Danger!
Imminent danger to life or risk of
severe personal injury
Danger!
Risk of death from electric shock
Warning.
Risk of minor personal injury
Caution.
Risk of material or environmental
damage
1.2 Risk caused by inadequate
qualifications
The following work must only be carried out
by competent persons who are sufficiently
qualified to do so:
–Set-up
–Dismantling
–Installation
–Start-up
–Inspection and maintenance
–Repair
–Decommissioning
▶Proceed in accordance with current tech-
nology.
1.3 Intended use
There is a risk of injury or death to the user or
others, or of damage to the product and other
property in the event of improper use or use
for which it is not intended.
The product is intended as a system com-
ponent for domestic hot water generation and
storage for closed central heating installa-
tions.
Intended use includes the following:
–observance of accompanying operating,
installation and maintenance instructions
for the product and any other system com-
ponents
–installing and setting up the product in ac-
cordance with the product and system ap-
proval
–compliance with all inspection and main-
tenance conditions listed in the instruc-
tions.
Intended use also covers installation in ac-
cordance with the IP code.
Any other use that is not specified in these
instructions, or use beyond that specified in
this document, shall be considered improper
use. Any direct commercial or industrial use
is also deemed to be improper.
Caution.
Improper use of any kind is prohibited.
1.4 General safety information
1.4.1 Risk of death due to lack of safety
devices
The basic diagrams included in this docu-
ment do not show all safety devices required
for correct installation.
▶Install the necessary safety devices in the
installation.
▶Observe the applicable national and inter-
national laws, standards and directives.
1.4.2 Risk of death from electric shock
There is a risk of death from electric shock if
you touch live components.
Before commencing work on the product:
▶Disconnect the product from the power
supply by switching off all power supplies
at all poles (electrical partition with a con-
tact gap of at least 3 mm, e.g. fuse or cir-
cuit breaker).
▶Secure against being switched back on
again.
▶Check that there is no voltage.
1.4.3 Risk of being burned or scalded by
hot components
▶Only carry out work on these components
once they have cooled down.

1 Safety
4Installation and maintenance instructions uniSTOR 0020221297_05
1.4.4 Risk of material damage caused by
using an unsuitable tool
▶Use the correct tool.
1.4.5 Risk of material damage caused by
frost
▶Do not install the product in rooms prone
to frost.
1.4.6 Risk of injury due to the heavy weight
of the product
▶Make sure that the product is transported
by at least two people.
1.5 Regulations (directives, laws,
standards)
▶Observe the national regulations, stand-
ards, directives, ordinances and laws.

Notes on the documentation 2
0020221297_05 uniSTOR Installation and maintenance instructions 5
2 Notes on the documentation
2.1 Observing other applicable documents
▶Always observe all the operating and installation instruc-
tions included with the system components.
2.2 Storing documents
▶Pass these instructions and all other applicable docu-
ments on to the end user.
2.3 Validity of the instructions
These instructions apply only to:
Product article number
VIH GB 120/3 BES 0010019215
VIH GB 150/3 BES 0010019216
VIH GB 180/3 BES 0010019217
VIH GB 200/3 BES 0010019218
VIH GB 250/3 BES 0010019219
VIH GB 300/3 BES 0010019220
2.4 Benchmark
Vaillant is a licensed member of the Benchmark Scheme.
Benchmark places responsibilities on both manufacturers
and installers. The purpose is to ensure that customers are
provided with the correct equipment for their needs, that it is
installed, commissioned and serviced in accordance with the
manufacturer’s instructions by a competent person approved
at the time by the Health and Safety Executive and that it
meets the requirements of the appropriate Building Regu-
lations. The Benchmark Checklist can be used to demon-
strate compliance with Building Regulations and should be
provided to the customer for future reference.
Installers are required to carry out installation, commission-
ing and servicing work in accordance with the Benchmark
Code of Practice which is available from the Heating and
Hotwater Industry Council who manage and promote the
Scheme.
Benchmark is managed and promoted by the Heating and
Hotwater Industry Council.
For more information visit www.centralheating.co.uk
3 Product description
3.1 Serial number
1
You can find the serial number on the data plate (1), which is
located on the cylinder below the electronics box.
3.2 Information on the identification plate
The identification plate is attached to the product at the fact-
ory.
The identification plate keeps record of the country in which
the product is to be installed.
This product meets the requirements of standard EN
12897:2006.
3.3 CE marking
The CE marking shows that the products comply with the
basic requirements of the applicable directives as stated on
the declaration of conformity.
The declaration of conformity can be viewed at the manufac-
turer's site.

4 Set-up
6Installation and maintenance instructions uniSTOR 0020221297_05
3.4 Hot Water Association
Vaillant is a full member of the Hot Water Association and
promotes the scheme in association with its cylinder range.
Details are available on the web site www.vaillant.co.uk
4 Set-up
4.1 Observing the requirements for the
product's installation site
Caution.
Material damage due to frost
If the water in the system freezes, there is
a risk of damage to the domestic hot water
cylinder.
▶Install the cylinder in a dry, permanently
frost-free room.
Caution.
Material damage due to escaping water
In the event of damage, water may escape
from the cylinder.
▶Select the installation location so that, in
the event of damage, large volumes of
water can be drained safely (e.g. into a
floor drain).
Caution.
Material damage due to high load
When filled, the cylinder may damage the
ground on which it stands due to its weight.
▶Take into consideration the weight of the
filled cylinder and the load-bearing capa-
city of the floor.
▶If required, reinforce the installation area.
Select a sensible installation site and take into consideration
the routing of the pipework system.
Install the cylinder as close as possible to the heat generator
in order to minimise heat losses.
Set up the product in a suitable location in a room and, when
doing so, pay attention to the following points:
–Plan the installation of the tundish (→Page 9).
–The installation surface must be even and have sufficient
load-bearing capacity to support the operating weight of
the product.
–The installation site must be frost-free.
–Install the product in such a way that the thermostat and
immersion heater can be accessed easily.
–Leave sufficient space around the product for installing,
maintaining and replacing the expansion vessel.
To prevent heat losses, the pipework system must have heat
insulation in accordance with the applicable energy-saving
regulations.
4.2 Transport
Caution.
Risk of material damage caused by incor-
rect transport.
The components attached to the cylinder
must not be used to transport the cylinder.
Otherwise there is a risk that the cylinder
could malfunction.
▶Do not use the components attached to
the cylinder to transport it.
Always transport the unit as illustrated above.
Never transport the unit while it is horizontal.

Set-up 4
0020221297_05 uniSTOR Installation and maintenance instructions 7
4.3 Unpacking the product
1. Remove the product from its box.
2. Remove the protective film from all of the product's
components.
4.4 Checking the scope of delivery
1
2
3
4
5
6
7
▶Check that the scope of delivery is complete.
Refer-
ence
point
Quant-
ity
Description
1 1 Enclosed documentation
2 1 Tundish with retainer
3 1 2-way motorised valve
4 1 Safety group
5 1 Expansion vessel
6 1 Bag with accessories
7 1 Domestic hot water cylinder and temper-
ature and pressure relief valve
4.5 Product dimensions
Ø 595
638
90°
265
154
A
B
C
D
Dimensions (mm)
A B C D
VIH GB 120/3
BES 840 555 379 317
VIH GB 150/3
BES 1,000 675 379 317
VIH GB 180/3
BES 1,165 840 495 380
VIH GB 200/3
BES 1,265 940 495 380
VIH GB 250/3
BES 1,535 1,210 495 380
VIH GB 300/3
BES 1,745 1,420 495 380

5 Installation
8Installation and maintenance instructions uniSTOR 0020221297_05
5 Installation
5.1 Setting up the unit horizontally
▶Align the product vertically by adjusting the adjustable
feet.
5.2 Hydraulic connection
Caution.
Risk of damage caused by heat transfer
when welding.
The heat that is transferred during welding
may damage the cylinder and its components
as well as the connection seals.
▶Protect the product and its components.
▶Do not weld the connection pieces if these
have been screwed into the pipe fittings.
Caution.
Risk of material damage by drilling
through the product.
The product may be damaged by drilling
work.
▶Do not drill through the product.
Caution.
Risk of material damage to the cylinder.
If an unvented hot water cylinder is fitted at
a high level (eg, loft space), potential dam-
age to the cylinder may occur if the correct
method of draining is not followed.
▶In certain circumstances and at the dis-
cretion of the installer, install a WRAS ap-
proved automatic air vent on the hot water
outlet at the highest point.
4
5
7
6
9
8
10
1
2
3
11
1 Heat generator heating
return
2 Heat generator heating
flow
3 Temperature and pres-
sure expansion relief
valve
4 Domestic hot water
outlet
5 Safety assembly
6 Tundish
7 Expansion vessel
8 2-port motorised valve
9 Dry pocket for the tem-
perature sensor
10 Cold water inlet
11 Drain valve
5.2.1 Connecting the product to the heating circuit
1. Connect the product to the inlet (2) and the outlet (1) on
the heating circuit.
–Minimum diameter of the copper pipe: ≥22 mm
2. Ensure that the distance between the heat generator
and the product is as small as possible in order to pre-
vent heat losses.
Installing the 2-port motorised valve
AUTO
MAIN
OPEN
3. Install the 2-port motorised valve at the heating coil's
inlet or outlet.
4. For the 2-port motorised valve, follow the installation
direction that is marked by an arrow.
5. The 2-port motorised valve can be installed vertically or
horizontally. For horizontal installation, align the valve
head so that it is facing upwards.

Installation 5
0020221297_05 uniSTOR Installation and maintenance instructions 9
5.2.2 Installing the drain valve
The drain valve must be supplied by the customer.
Install the drain valve at the height of the cold water supply
or further below this level.
5.2.3 Installing the safety group
Caution.
Excessive pressure in the domestic hot
water cylinder
Excessive pressure in the domestic hot water
cylinder may cause the cylinder to burst.
▶Ensure that the expansion relief valves
are not blocked.
▶Ensure that there is no isolation valve
between the safety group and the cylin-
der.
2
34
5
6
7
8
1
1 Cold water with equal
pressure
2 Cold water inlet (22
mm)
3 Pressure reducer
4 Expansion relief valve
5 Outlet for the expansion
relief valve (15 mm)
6 Connection for the
expansion vessel (22
mm)
7 Flow of the cold water
supply to the cylinder
8 Connecting a mano-
meter (optional, not in-
cluded in the scope of
delivery)
1. Before installation, flush the pipes in order to clear any
contamination and prevent the build up of dirt.
2. Install the safety group horizontally and install the ex-
pansion relief valve so that it is facing upwards.
3. Note the flow direction, which is specified by an arrow.
4. Connect the safety assembly to the drain valve. Consult
the table below to find out the length to which the pipe
should be cut.
Size of the
cylinder
Length of the pipe
that has a diameter
of 22 mm
Pre-charge pres-
sure of the expan-
sion vessel
120 600 mm 0.3 MPa
(3.0 bar)
150 800 mm 0.3 MPa
(3.0 bar)
Size of the
cylinder
Length of the pipe
that has a diameter
of 22 mm
Pre-charge pres-
sure of the expan-
sion vessel
180 800 mm 0.3 MPa
(3.0 bar)
210 900 mm 0.3 MPa
(3.0 bar)
250 1,150 mm 0.3 MPa
(3.0 bar)
300 1,350 mm 0.3 MPa
(3.0 bar)
Note
If you have to set up a secondary return,
install the T-piece supplied for the VIH GB
250/3 BES and VIH GB 300/3 BES products.
5. Install a pipe between the safety assembly's connection
(5) and the temperature and pressure relief valve. Use
a T-piece for this. The pipe system must continuously
slope outwards, must be visible and must be protected
against frost. There must be no risk of injury to persons.
–Diameter of the pipe: 15 mm
–Length of the hose between the temperature and
pressure expansion relief valve and the expansion
relief valve (4):≤600 mm
6. Connect the cold water supply to the safety group (2).
–Diameter of the cold water supply pipe: ≥22 mm
5.2.4 Installing an expansion vessel
1. Install the expansion vessel close to the product.
2. Install a pipe at the expansion vessel and connect the
terminal to the safety assembly (6).
5.2.5 Installing a discharge pipe
≤ 600 mm
≥ 300 mm
D2
2
1
D1
1 Temperature and pres-
sure expansion relief
valve
2 Tundish
The drain connections of the temperature and pressure re-
lief valve and the expansion relief valve must be connected
to the supplied tundish via 15-mm-thick copper pipes. The
tundish must be installed vertically, as close to the cylinder
as possible and with a maximum clearance of 600 mm from
the connection of the temperature and pressure relief valve.
It must be installed in the same room as the cylinder, but at

5 Installation
10 Installation and maintenance instructions uniSTOR 0020221297_05
a sufficient distance from electrical components. The drain
pipes from the temperature and pressure relief valve and
from the expansion relief valve can be connected above the
tundish using a T-piece. The drain pipe from the 22 mm con-
nection of the tundish must consist of copper pipes with a
diameter of at least 22 mm and be connected to a safe and
visible drainage point. The vertical section of pipe beneath
the tundish must be at least 300 mm long before any bends
or diversions in the line. If the total resistance of the drain
pipework exceeds the values in the following table, you must
increase the diameter of the pipework. When installing the
drain pipework, comply with the standards, directives and
laws that are applicable in your country.
Size of
the outlet
valve
Minimum
diameter
of the
discharge
pipe D1
Minimum
diameter
of the dis-
charge
pipe from
the tun-
dish D2
Maximum
permiss-
ible res-
istance,
inform-
ation
on the
length of
a straight
pipe
Resist-
ance per
elbow or
bend
1/2" 15 mm
22 mm
28 mm
35 mm
9 mm
≤18 m
≤27 m
0.8 m
1.0 m
1.4 m
3/4" 22 mm
28 mm
35 mm
42 mm
≤9 m
≤18 m
≤27 m
1.0 m
1.4 m
1.7 m
1" 28 mm
35 mm
42 mm
54 mm
≤9 m
≤18 m
≤27 m
1.4 m
1.7 m
2.3 m
Sample calculation
The following example corresponds to a temperature and
pressure relief valve G1/2 with a drain pipe (D2) with four 22
mm elbows and a length of 7 m from the tundish to the drain-
age point. According to the table, the maximum permiss-
ible resistance for a straight length of a 22-mm-thick cop-
per discharge pipe (D2) of a thermal expansion relief valve
G1/2 is 9.0 m. The resistance of the four 22 mm elbows,
which are each 0.8 m in length, must be subtracted from this,
i.e. a total of 3.2 m. The maximum permitted length is ac-
cordingly 5.8 m and is therefore below the current length of
7 m. The calculation must therefore be performed using the
second largest size. The maximum permissible resistance
for a straight length of a 28-mm-thick pipe (D2) of a thermal
expansion relief valve G1/2 is 18 m. The resistance of the
four 28 mm elbows, which are each 1.0 m in length, must be
subtracted from this, i.e. a total of 4.0 m. The maximum per-
mitted length is accordingly 14 m. As the current length is
7 m, a 28 mm copper pipe (D2) should be selected.
A suitable location for the discharge pipe terminal is, for
example, beneath a fixed mesh above the odour trap in a
soakaway with a siphon. Low drain pipework, for example
up to 100 mm above external surfaces (car parks, mead-
ows, etc.) can be used provided that it is protected by a wire
fence or something similar to prevent children from coming
into contact with the waste water and provided that the sys-
tem is not visible. Do not install any valves or stopcocks on
the drain pipework.
Make sure that the discharge pipe from the tundish to the
drain has a constant downward gradient of at least 1:200.
The discharge pipe for the heat generator expansion relief
valve can be connected to the horizontal discharge pipe for
the cylinder behind the tundish using a T-piece.
5.2.5.1 High-level drain
Installing the highest drain is permitted as long as this does
not present a danger to anyone in or outside the building at
the drain point. Examples of points to consider when decid-
ing whether a location is suitable for the highest drain:
–The possibility (taking the wind into account) that a per-
son might stay in the area where the water is drained
for a prolonged period of time, and, if this is the case,
whether the water is sufficiently cooled by that point to
pose no danger. The thermal conductivity of the material
surfaces, the climatic conditions, the installation location
and the drain pipework direction can, to different extents,
contribute to reducing the temperature of the water that is
being drained.
–The position of the windows and other openings.
–The probability of prams being under the drain opening.
–The resistance of the surface to hot water.
–The possibility of ice forming if water drains onto access
paths.
5.2.6 Installing the temperature sensor for the
immersion heater
Note
The temperature sensor is used to control the
immersion heater via a multi-functional module
or a control.
Condition: With a multi-functional module or control
▶Secure the temperature sensor.

Installation 5
0020221297_05 uniSTOR Installation and maintenance instructions 11
5.2.7 Installing a secondary return
Validity: VIH GB 250/3 BES
OR VIH GB 300/3 BES
1
23
4
5
1 T-piece for the second-
ary return (included in
the scope of delivery for
the cylinder)
2 Domestic hot water
outlet
3 Secondary return pipe
4 Circulation pump
5 Non-return valve
Carry out the installation in accordance with the basic dia-
gram above.
5.3 Electrical installation
Danger!
Risk of death from electric shock!
The power supply terminals L and N are live:
▶Switch off the power supply.
▶Secure the power supply against being
switched back on.
Caution.
Risk of material damage by drilling
through the product.
The product may be damaged by drilling
work.
▶Do not drill through the product.
70
60 50
40 70
60 50
40
13
24
13
24
1
2
3
4
1 Immersion heater
2 Immersion heater ther-
mostat
3 Primary circuit thermo-
stat
4 Retainer for the temper-
ature sensor
5.3.1 Optional combination of thermostats
Use the wiring diagram in the system instructions for the
installation.
5.3.2 Thermostats
70
60 50
40 70
60 50
40
13
24
13
24
1 2
34
1 Thermal cut-out and re-
set knob for the immer-
sion heater
2 Thermal cut-out and re-
set knob for the primary
circuit
3 Setting the temperature
of the primary circuit
4 Immersion heater tem-
perature control

5 Installation
12 Installation and maintenance instructions uniSTOR 0020221297_05
5.3.3 Cable route
▶Use the grommets that are included in the scope of deliv-
ery for the cylinder in the electronics box.
5.3.4 Connecting the immersion heater to the
power supply
70
60 50
40 70
60 50
40
13
24
13
24
LN
1
L N
3
24
1
2
2
1. Remove the cover for the electrics on the cylinder.
2. Install a separate power supply for the immersion
heater in accordance with the applicable standards.
3. Use heat-resistant cables for the immersion heater con-
nection.
–Diameter of the cable: 1.5 mm²
4. Connect the thermal cut-out to the mains power supply
using a double-pole disconnector with a contact gap of
at least 3 mm at both poles.
5. Protect the electrical circuit using a fuse.
–Fuse: 13 A
6. Connect the immersion heater as shown in the basic
diagram.
7. Attach the cover for the electrics on the cylinder.
5.3.5 Electrical connection of the temperature
sensor
Condition: With a multi-functional module or control
▶Connect the temperature sensor to the multi-functional
module or the control; to do this, see the instructions for
the control or multi-functional module.

Start-up 6
0020221297_05 uniSTOR Installation and maintenance instructions 13
5.3.6 Connecting the control
Condition: eBUS
The thermal cut-out for the primary circuit is not used when
connecting an eBUS unit.
Condition: 230 V control
If you use a 230 V control from a third-party manufacturer,
connect the thermal cut-out (2) and (3) for the primary circuit
with the 2-way motorised valve to isolate the heat source in
the event of a fault in the 2-way motorised valve.
5.3.7 Electric connection for the primary circuit
1. Connect the thermostat for the primary circuit and the
thermal cut-out.
–Diameter of the cable: 1.5 mm²
Condition: S plan
70
60 50
40 70
60 50
40
13
24
13
24
LN
2
13
2
2
4
4
1
8
L
8L
8L
SL
▶Connect the assembly.
Condition: Y plan
70
60 50
40 70
60 50
40
13
24
13
24
LN
2
13
2
2
4
4
1
8
L
8L
8L
SL
1
▶Connect the plug (1) to the electronics box.
5.3.8 Connecting the 2-port motorised valve to the
power supply
▶Connect the 2-port motorised valve; to do this, see the
instructions for the control or multi-functional module.
6 Start-up
6.1 Setting the immersion heater thermostat
70
60 50
40 70
60 50
40
13
24
13
24
1
The domestic hot water temperature is controlled via the
immersion heater thermostat (1).

7 Handing the product over to the end user
14 Installation and maintenance instructions uniSTOR 0020221297_05
Condition: Without a multi-functional module or control
▶Set the domestic hot water temperature as desired.
Condition: With multi-functional module or control
▶Set the immersion heater thermostat (1) to its maximum.
The temperature of the immersion heater is regulated via
the temperature sensor that is installed on the carrier in the
electronics box.
6.2 Cold water inlet pressure
The product's efficiency depends on the cold water inlet
pressure.
To achieve optimum efficiency, we recommend a pressure of
at least 2 bar.
6.3 Filling and purging the product
Note
It is not permitted to use valves or expansion relief
valves for the purging.
1. Check whether the drain valve is closed.
2. Open the domestic hot water draw-off valves.
3. Open the water supply valve.
4. Open the manual air separator at the top of the cylinder.
5. Let the water flow in order to remove any air bubbles.
6. Close the manual air separator as soon as all of the air
has escaped.
7. Close the domestic hot water draw-off valves.
8. Check whether there are any leaks. Check the immer-
sion heater in particular.
9. Open the highest hot water supply valve, and then the
lowest hot water supply valve, and let the water flow.
–Water running time: ≥5 min
10. Close all of the draw-off valves.
6.4 Filling and purging the heating circuit
Note
The heating circuit can be filled using a filling
device or a separate filling tap, which is installed
at a location that is easily accessible.
The separate filling tap must be removed after
filling.
If a filling device is used, close the filling valve and
remove the filling device.
If you are not permitted to use a separate filling
tap due to legal provisions, use a pump.
1. Move the lever on the 2-port motorised valve to MAN
OPEN and hold it in this position.
2. Flush out the heating circuit and then fill and purge it.
Consult the installation instructions for the heat gener-
ator.
3. Move the lever to AUTO.
4. Remove the cover for the electrics.
5. Set the product's thermostat and the immersion heater's
thermostat.
–Setting the thermostats: 60 ℃
6. Start up the heat generator.
7. Drain the heating circuit as soon as the operating
temperature has been reached in order to remove any
residue from the heating installation.
8. Fill and purge the heating circuit. Consult the installation
instructions for the heat generator.
7 Handing the product over to the end
user
▶Once the installation is complete, show the user the loca-
tion and function of the safety devices.
▶Inform the end user how to handle the product.
▶In particular, draw attention to the safety warnings which
the end user must follow.
▶Inform the end user of the necessity to have the product
maintained according to the specified intervals.
8 Troubleshooting
8.1 Detecting and eliminating faults
▶If problems occur whilst operating the product, check
certain points with the aid of the table in the appendix.
Detecting and eliminating faults (→Page 16)
8.2 Procuring spare parts
The original components of the product were also certified
by the manufacturer as part of the declaration of conformity.
If you use other, non-certified or unauthorised parts during
maintenance or repair work, this may void the conformity of
the product and it will therefore no longer comply with the
applicable standards.
We strongly recommend that you use original spare parts
from the manufacturer as this guarantees fault-free and safe
operation of the product. To receive information about the
available original spare parts, contact the contact address
provided on the back page of these instructions.
▶If you require spare parts for maintenance or repair
work, use only the spare parts that are permitted for the
product.
9 Inspection and maintenance
9.1 Observing inspection and maintenance
intervals
Adhere to the minimum inspection and maintenance inter-
vals. The inspection may require maintenance to be carried
out earlier, depending on the results.
Inspection and maintenance work –Overview (→Page 16)
The immersion heater can be removed in order to inspect
the inside of the cylinder.

Decommissioning the product 10
0020221297_05 uniSTOR Installation and maintenance instructions 15
9.2 Draining the product
1. Close the cold water draw-off valve.
2. Secure a hose to the drain valve.
3. Position the hose at a suitable drain.
4. Open the highest hot water tap in the installation.
5. Open the drain valve and drain the product completely.
6. Close the hot water tap and the drain valve.
7. Remove the hose.
9.3 Checking the safety group's expansion
relief valve and the cylinder's expansion
relief valve
1. Open all expansion relief valves by turning the plug.
2. Check whether the water is flowing into the tundish.
3. Check that the expansion relief valves are in the correct
position and then check the pressure.
4. Check and, if required, clean the pressure reducer.
9.4 Checking the pre-charge pressure of the
expansion vessel
1. Drain the product. (→Page 15)
2. Measure the pre-charge pressure of the expansion ves-
sel at the vessel valve.
Condition: Pressure <0.3 MPa (0.3 bar)
▶Top up the expansion vessel in accordance with the
static height of the heating installation, ideally with ni-
trogen, otherwise with air.
3. If water escapes from the valve of the expansion ves-
sel, you must replace the expansion vessel.
4. Fill and purge the product. (→Page 14)
10 Decommissioning the product
▶Switch off the heat generator.
▶Unplug the domestic hot water cylinder's mains plug.
▶Close the cold-water stopcock.
▶Drain the product. (→Page 15)
▶Remove the hydraulic connections and the temperature
sensor.
▶Remove the cables for the temperature sensor from the
heat generator, control or multi-functional module.
11 Customer service
To ensure regular servicing, it is strongly recommended
that arrangements are made for a Maintenance Agreement.
Please contact Vaillant Service Solutions for further details:
Telephone: [phone]

Appendix
16 Installation and maintenance instructions uniSTOR 0020221297_05
Appendix
A Detecting and eliminating faults
Fault Possible cause Remedy
No flow rate at the valve 1. Water supply valve closed
2. Main filter blocked
3. Pressure reducer not installed correctly
1. Check and open the valve.
2. Close the water supply valve, clean the filter
and the water pressure reducer.
3. Check whether the pressure reducer has been
installed correctly.
Low flow rate and pres-
sure at a valve
1. Filter in cold water supply clogged 1. Close the cold water supply, clean the filter for
the water pressure reducer.
Water from the valve is
cold
1. The cylinder was not set or is not operating.
2. The heat generator does not work.
3. The thermal cut-out was triggered.
4. The 2-port motorised valve is not working
5. The immersion heater does not work.
1. Check the thermostat or the room thermostat
and, if required, set this.
2. Check the heat generator; a fault code is
present.
3. Check and initialise the cylinder.
4. Check the valve's connections.
5. Set the thermostat or the room thermostat.
Domestic hot water
temperature too high
1. Use a thermometer to check the temperature; it
must be between 60 and 65 °C.
2. Check the cabling.
3. Thermostat set too high
4. Defective thermostat
1. Install a mixer tap.
2. Repair the cable.
3. Reduce the temperature of the thermostat to
55 °C.
4. Replace the thermostat.
Irregular domestic hot
water output at the valve
1. Defective expansion vessel
2. Thermal control
1. Set the expansion vessel.
2. Interrupt the power supply of the product and
heat generator, check the thermal cut-outs and
replace these if you find any defects.
B Inspection and maintenance work –Overview
N° Work Maintenance-re-
lated interval
1 Check the connections for tightness. Annually
2 Check the temperature and pressure expansion relief valve. Annually
3 Check the expansion relief valve. Annually
4 Check the pressure in the expansion vessel. Annually
5 Check the domestic hot water output at the valve (if required, clean the filters). Annually
6 Check the target domestic hot water temperature. Annually
7 Fill out the cylinder's benchmark checklist. Annually
C Technical data
Technical data –General
VIH GB
120/3 BES
VIH GB
150/3 BES
VIH GB
180/3 BES
VIH GB
200/3 BES
VIH GB
250/3 BES
VIH GB
300/3 BES
Actual volumetric capacity 114.8 l 144.9 l 175.2 l 194.0 l 244.8 l 284.3 l
Hot water volumetric capacity 106.0 l 135.2 l 161.0 l 170.0 l 229.0 l 254.0 l
Maximum pressure of the heating
tube coil during operation
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
Operating pressure 0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
Maximum operating pressure 0.7 MPa
(7.0 bar)
0.7 MPa
(7.0 bar)
0.7 MPa
(7.0 bar)
0.7 MPa
(7.0 bar)
0.7 MPa
(7.0 bar)
0.7 MPa
(7.0 bar)
Pressure of the pressure reducer 0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
0.35 MPa
(3.50 bar)
Opening pressure in the expansion
relief valve
0.6 MPa
(6.0 bar)
0.6 MPa
(6.0 bar)
0.6 MPa
(6.0 bar)
0.6 MPa
(6.0 bar)
0.6 MPa
(6.0 bar)
0.6 MPa
(6.0 bar)

Appendix
0020221297_05 uniSTOR Installation and maintenance instructions 17
VIH GB
120/3 BES
VIH GB
150/3 BES
VIH GB
180/3 BES
VIH GB
200/3 BES
VIH GB
250/3 BES
VIH GB
300/3 BES
Temperature and pressure expansion
relief valve
0.7 MPa
(7.0 bar)
0.7 MPa
(7.0 bar)
0.7 MPa
(7.0 bar)
0.7 MPa
(7.0 bar)
0.7 MPa
(7.0 bar)
0.7 MPa
(7.0 bar)
Temperature and pressure expansion
relief valve
90 ℃90 ℃90 ℃90 ℃90 ℃90 ℃
Load pressure in the expansion ves-
sel
0.3 MPa
(3.0 bar)
0.3 MPa
(3.0 bar)
0.3 MPa
(3.0 bar)
0.3 MPa
(3.0 bar)
0.3 MPa
(3.0 bar)
0.3 MPa
(3.0 bar)
Maximum temperature of the heating
circuit
95 ℃95 ℃95 ℃95 ℃95 ℃95 ℃
Maximum domestic hot water temper-
ature
85 ℃85 ℃85 ℃85 ℃85 ℃85 ℃
Heat loss (24 hrs) 0.83 kWh 0.86 kWh 1.11 kWh 1.22 kWh 1.41 kWh 1.59 kWh
Reheating time 20.42 min 26.60 min 29.58 min 31.61 min 43.34 min 48.50 min
Reheating time (70%) 14.29 min 18.62 min 20.71 min 22.13 min 30.34 min 33.95 min
Reheating output 15.8 kW 17.2 kW 17.1 kW 16.9 kW 16.6 kW 16.5 kW
Flow rate 900 l/h 900 l/h 900 l/h 900 l/h 900 l/h 900 l/h
Pressure loss in the primary heat ex-
changer
50 mbar 50 mbar 50 mbar 50 mbar 50 mbar 50 mbar
Volume of the heat exchanger 3.7 l 3.7 l 4.4 l 4.4 l 4.4 l 4.4 l
Surface of the heat exchanger 0.69 m²0.69 m²0.80 m²0.80 m²0.80 m²0.80 m²
Volume of the expansion vessel 12 l 12 l 18 l 18 l 25 l 25 l
Tilt dimension 1,020 mm 1,150 mm 1,300 mm 1,390 mm 1,640 mm 1,840 mm
Net weight 30.0 kg 35.0 kg 39.0 kg 42.0 kg 48.0 kg 54.0 kg
Weight including heating water and
domestic hot water
148.5 kg 183.6 kg 218.6 kg 240.4 kg 297.2 kg 342.7 kg
Technical data –Hydraulic connection
VIH GB
120/3 BES
VIH GB
150/3 BES
VIH GB
180/3 BES
VIH GB
200/3 BES
VIH GB
250/3 BES
VIH GB
300/3 BES
Cold water inlet 0.75 in 0.75 in 0.75 in 0.75 in 0.75 in 0.75 in
Domestic hot water outlet 0.75 in 0.75 in 0.75 in 0.75 in 0.75 in 0.75 in
Heat generator heating flow 0.75 in 0.75 in 0.75 in 0.75 in 0.75 in 0.75 in
Heat generator heating return 0.75 in 0.75 in 0.75 in 0.75 in 0.75 in 0.75 in
Temperature dry pocket 8 mm 8 mm 8 mm 8 mm 8 mm 8 mm
Immersion heater diameter 1 1/4 in 1 1/4 in 1 1/4 in 1 1/4 in 1 1/4 in 1 1/4 in
Technical data –Electrics
VIH GB
120/3 BES
VIH GB
150/3 BES
VIH GB
180/3 BES
VIH GB
200/3 BES
VIH GB
250/3 BES
VIH GB
300/3 BES
Connecting the immersion heater to
the power supply
230 V /
50 Hz
230 V /
50 Hz
230 V /
50 Hz
230 V /
50 Hz
230 V /
50 Hz
230 V /
50 Hz
Immersion heater power 2.8 kW 2.8 kW 2.8 kW 2.8 kW 2.8 kW 2.8 kW
2-port motorised valve 230/240 V,
50Hz
230/240 V,
50Hz
230/240 V,
50Hz
230/240 V,
50Hz
230/240 V,
50Hz
230/240 V,
50Hz
Thermostat 230/240 V,
50Hz
230/240 V,
50Hz
230/240 V,
50Hz
230/240 V,
50Hz
230/240 V,
50Hz
230/240 V,
50Hz
IP rating 21 21 21 21 21 21
Technical data –Material
VIH GB
120/3 BES
VIH GB
150/3 BES
VIH GB
180/3 BES
VIH GB
200/3 BES
VIH GB
250/3 BES
VIH GB
300/3 BES
Cylinder material Stainless
steel
(1.4521)
Stainless
steel
(1.4521)
Stainless
steel
(1.4521)
Stainless
steel
(1.4521)
Stainless
steel
(1.4521)
Stainless
steel
(1.4521)
Insulation material Polyurethane Polyurethane Polyurethane Polyurethane Polyurethane Polyurethane
Insulation thickness 50 mm 50 mm 50 mm 50 mm 50 mm 50 mm

Appendix
18 Installation and maintenance instructions uniSTOR 0020221297_05
VIH GB
120/3 BES
VIH GB
150/3 BES
VIH GB
180/3 BES
VIH GB
200/3 BES
VIH GB
250/3 BES
VIH GB
300/3 BES
Propellant for insulating material GWP < 5 GWP < 5 GWP < 5 GWP < 5 GWP < 5 GWP < 5
ODP 000000

Appendix
0020221297_05 uniSTOR Installation and maintenance instructions 19
D Commissioning Checklist

Appendix
20 Installation and maintenance instructions uniSTOR 0020221297_05
This Commissioning Checklist is to be completed in full by the competent person who commissioned the storage system as a means of
demonstrating compliance with the appropriate Building Regulations and then handed to the customer to keep for future reference.
Failure to install and commission this equipment to the manufacturer’s instructions may invalidate the warranty but does not affect statutory rights.
MAINS PRESSURE HOT WATER STORAGE SYSTEM COMMISSIONING CHECKLIST
Customer name: Telephone number:
Address:
Cylinder Make and Model
Cylinder Serial Number
Commissioned by (PRINT NAME): Registered Operative ID Number
Company name: Telephone number:
Company address:
Commissioning date:
7REHFRPSOHWHGE\WKHFXVWRPHURQUHFHLSWRID%XLOGLQJ5HJXODWLRQV&RPSOLDQFH&HUWL¿FDWH
%XLOGLQJ5HJXODWLRQV1RWL¿FDWLRQ1XPEHULIDSSOLFDEOH
ALL SYSTEMS PRIMARY SETTINGS (indirect heating only)
Is the primary circuit a sealed or open vented system? Sealed Open
:KDWLVWKHPD[LPXPSULPDU\ÀRZWHPSHUDWXUH" °C
ALL SYSTEMS
What is the incoming static cold water pressure at the inlet to the system? bar
+DVDVWUDLQHUEHHQFOHDQHGRILQVWDOODWLRQGHEULVLI¿WWHG" Yes N o
Is the installation in a hard water area (above 200ppm)? Yes N o
,I\HVKDVDZDWHUVFDOHUHGXFHUEHHQ¿WWHG" Yes N o
:KDWW\SHRIVFDOHUHGXFHUKDVEHHQ¿WWHG"
What is the hot water thermostat set temperature? °C
:KDWLVWKHPD[LPXPKRWZDWHUÀRZUDWHDWVHWWKHUPRVWDWWHPSHUDWXUHPHDVXUHGDWKLJKÀRZRXWOHW" I/min
7LPHDQGWHPSHUDWXUHFRQWUROVKDYHEHHQ¿WWHGLQFRPSOLDQFHZLWK3DUW/RIWKH%XLOGLQJ5HJXODWLRQV" Yes
Type of control system (if applicable) Y Plan S Plan Other
Is the cylinder solar (or other renewable) compatible? Ye s No
What is the hot water temperature at the nearest outlet? °C
All appropriate pipes have been insulated up to 1 metre or the point where they become concealed Yes
UNVENTED SYSTEMS ONLY
:KHUHLVWKHSUHVVXUHUHGXFLQJYDOYHVLWXDWHGLI¿WWHG"
What is the pressure reducing valve setting? bar
+DVDFRPELQHGWHPSHUDWXUHDQGSUHVVXUHUHOLHIYDOYHDQGH[SDQVLRQYDOYHEHHQ¿WWHGDQGGLVFKDUJHWHVWHG" Yes N o
The tundish and discharge pipework have been connected and terminated to Part G of the Building Regulations Yes
$UHDOOHQHUJ\VRXUFHV¿WWHGZLWKDFXWRXWGHYLFH" Yes N o
Has the expansion vessel or internal air space been checked? Yes No
THERMAL STORES ONLY
What store temperature is achievable? °C
What is the maximum hot water temperature? °C
ALL INSTALLATIONS
The hot water system complies with the appropriate Building Regulations Yes
The system has been installed and commissioned in accordance with the manufacturer’s instructions Yes
The system controls have been demonstrated to and understood by the customer Yes
The manufacturer’s literature, including Benchmark Checklist and Service Record, has been explained and left with the customer Yes
Commissioning Engineer’s Signature
Customer’s Signature
7RFRQ¿UPVDWLVIDFWRU\GHPRQVWUDWLRQDQGUHFHLSWRIPDQXIDFWXUHU¶VOLWHUDWXUH
$OOLQVWDOODWLRQVLQ(QJODQGDQG:DOHVPXVWEHQRWL¿HGWR/RFDO$XWKRULW\%XLOGLQJ&RQWURO/$%&HLWKHUGLUHFWO\RUWKURXJKD
&RPSHWHQW3HUVRQV6FKHPH$%XLOGLQJ5HJXODWLRQV&RPSOLDQFH&HUWL¿FDWHZLOOWKHQEHLVVXHGWRWKHFXVWRPHU
© Heating and Hotwater Industry Council (HHIC) www.centralheating.co.uk