Vaillant ecoTEC plus VU Series User manual

en Installation and maintenance instructions
ecoTEC plus
VU../VUW..
0020308118_05 - 31.05.2023

2Installation and maintenance instructions 0020308118_05
Installation and maintenance
instructions
Contents
1 Safety .................................................................... 4
1.1 Intended use .......................................................... 4
1.2 Qualification ........................................................... 4
1.3 General safety information .................................... 4
1.4 Regulations (directives, laws, standards) .............. 7
1.5 List of relevant standards for Great Britain and
Ireland.................................................................... 7
2 Guarantee and Customer Service...................... 8
3 Technical data...................................................... 9
4 Notes on the documentation ............................ 16
5 Product description........................................... 16
5.1 CE marking .......................................................... 16
5.2 UKCA mark.......................................................... 16
5.3 Hot Water Association ......................................... 16
5.4 Water Regulations Advisory Scheme .................. 16
5.5 Data plate ............................................................ 17
5.6 Serial number ...................................................... 17
5.7 Sitherm Pro™ technology.................................... 17
5.8 Display of the energy consumption, energy
yields and efficiencies.......................................... 17
5.9 Product design..................................................... 18
5.10 Design of the product's hydraulic block ............... 19
5.11 Safety Devices..................................................... 19
6 Set-up.................................................................. 19
6.1 Checking the scope of delivery............................ 19
6.2 Product dimensions ............................................. 20
6.3 Installation site ..................................................... 20
6.4 Minimum clearances............................................ 21
6.5 Compartment Ventilation ..................................... 21
6.6 Using the mounting template............................... 21
6.7 Wall-mounting the product................................... 21
7 Installation.......................................................... 21
7.1 Prerequisites........................................................ 21
7.2 Installing the air/flue pipe..................................... 23
7.3 Installing the gas connection ............................... 27
7.4 Installing the hot and cold water connection........ 28
7.5 Connecting the domestic hot water cylinder........ 28
7.6 Installing the heating flow and heating return ...... 28
7.7 Installing the heating flow and heating return ...... 28
7.8 Installing the condensate discharge .................... 28
7.9 Installing combined condensate and pressure
relief valve............................................................ 31
7.10 Electrical installation ............................................ 31
7.11 Installing the front casing..................................... 38
8 Operation............................................................ 38
8.1 Operating concept ............................................... 38
8.2 Calling up the installer level................................. 38
8.3 Calling up/setting diagnostics codes ................... 38
8.4 Running a check programme .............................. 38
8.5 Carrying out the actuator test .............................. 39
8.6 Calling up the data overview ............................... 39
8.7 Calling up status codes........................................ 39
8.8 Exiting the menu level.......................................... 39
8.9 Running the chimney sweep mode
(combustion analysis).......................................... 39
8.10 Switching on the button lock (Advanced Key
Lock) .................................................................... 39
9 Start-up ............................................................... 39
9.1 Pre-Commissioning checklist .............................. 39
9.2 Carrying out the initial start-up............................. 40
9.3 Checking and treating the heating water/filling
and supplementary water .................................... 40
9.4 Deactivating standby mode ................................. 41
9.5 Running through the installation assistant........... 41
9.6 Check programmes and actuator tests................ 42
9.7 Guaranteeing the system pressure ..................... 42
9.8 Flushing the heating installation for the first
time ("cold") ......................................................... 42
9.9 Filling the heating installation .............................. 43
9.10 Purging the heating installation ........................... 43
9.11 Filling and purging the domestic hot water
system ................................................................. 43
9.12 Filling the condensate siphon .............................. 44
9.13 Checking the gas settings ................................... 44
9.14 Thoroughly flushing the heating installation
("hot")................................................................... 47
9.15 Checking the heating mode................................. 48
9.16 Checking the domestic hot water generation ...... 48
9.17 Checking leak-tightness ...................................... 48
9.18 Converting the product to a different gas type..... 48
10 Adapting the unit to the installation ................ 48
10.1 Setting parameters .............................................. 48
10.2 Activating an additional component for the
multi-functional module........................................ 48
10.3 Adapting the heating mode settings .................... 49
10.4 Adapting the domestic hot water settings............ 53
10.5 Displaying the product information ...................... 53
11 Handing over to the end user........................... 53
12 Inspection and maintenance ............................ 54
12.1 Complete Service Interval Record section .......... 54
12.2 Using original seals.............................................. 54
12.3 Maintenance interval............................................ 54
12.4 Actuator test......................................................... 54
12.5 Inspection and maintenance................................ 54
12.6 Preparing the maintenance work......................... 54
12.7 Removing/installing the compact thermal
module ................................................................. 55
12.8 Cleaning/checking the components..................... 56
12.9 Draining the product ............................................ 58
12.10 Completing inspection and maintenance work .... 59
13 Troubleshooting ................................................ 59
13.1 Checking the data overview ................................ 59
13.2 Service messages ............................................... 59
13.3 Fault messages ................................................... 59
13.4 Limp home mode messages ............................... 59

0020308118_05 Installation and maintenance instructions 3
13.5 Resetting parameters to factory settings ............. 59
13.6 Eliminating faults in the product........................... 60
13.7 Replacing defective components......................... 60
14 Decommissioning.............................................. 68
14.1 Activate the standby mode .................................. 68
14.2 Temporarily decommissioning............................. 68
14.3 Permanently decommissioning............................ 68
15 Disposing of the packaging.............................. 68
Appendix ............................................................................ 69
A Tightening torques ............................................ 69
B Inspection and maintenance work................... 69
C Installer level ...................................................... 71
D Diagnostics codes ............................................. 72
E Status codes ...................................................... 79
F Fault codes......................................................... 80
G Check programmes ........................................... 91
H Actuator test....................................................... 91
I Maintenance codes............................................ 92
J Reversible limp home mode codes ................. 92
K Irreversible limp home mode codes ................ 92
L Wiring diagram................................................... 95
M Commissioning Checklist............................... 104
N Commissioning Flow Chart ............................ 108
Index ................................................................................. 109

4Installation and maintenance instructions 0020308118_05
1 Safety
1.1 Intended use
The product is intended as a heat generator
for sealed heating installations and for do-
mestic hot water generation.
Improper use of any kind is prohibited.
Intended use also includes the following:
–use of the product only in mobile homes
that are made, transported once and per-
manently situated in Great Britain and Ire-
land. After the transportation of the mo-
bile home to its destination the complete
product must be checked for leak-tightness
again
–validity of the product only for Great Britain
and Ireland and for the gas types in Great
Britain and Ireland as listed on the data
plate
–Installing and operating the product only
in conjunction with accessories for the
air/flue pipe which are listed in the other
applicable documents and comply with the
type of unit
–Using the product while observing the ac-
companying operating, installation and
maintenance instructions for the product
along with all other components of the in-
stallation
–Installing and setting up the product while
observing the product and system ap-
proval
–Observing all inspection and maintenance
conditions listed in the instructions
–Installing while observing the IP code
The following is classed as improper use:
–Using the product in vehicles, such
caravans. Units that are not classed as
vehicles are those that are installed in a
fixed and permanent location (known as
"fixed installation").
–Using the product in combination with dir-
ectly connected wall-hung domestic hot
water cylinders, whether in the case of a
replacement or for a new installation.
–Using the product for a multiple-flue config-
uration or as a cascade
–Any direct use in industrial or commercial
processes
–Any use other than those described in
these instructions and any use that goes
beyond what is described here
1.2 Qualification
The person carrying out the work described
here must have completed professional train-
ing. The competent person must demon-
strably have all of the knowledge, skills and
capabilities that are required in order to carry
out the work mentioned below.
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.
▶Use the correct tool.
The above-mentioned work must always only
be carried out by persons with sufficient qual-
ifications.
This product can be used by children aged
from 8 years and persons with reduced phys-
ical, sensory or mental capabilities or lack of
experience and knowledge if they have been
given supervision or instruction concerning
use of the product in a safe way and under-
stand the hazards involved. Children must
not play with the product. Cleaning and user
maintenance work must not be carried out by
children unless they are supervised.
1.3 General safety information
The following sections convey important
safety information. It is essential to read and
observe this information in order to prevent
risk of death, risk of injury, material damage
or environmental damage.
1.3.1 Gas
If you smell gas:
▶Avoid rooms that smell of gas.
▶If possible, open doors and windows fully
and ensure adequate ventilation.

0020308118_05 Installation and maintenance instructions 5
▶Do not use naked flames (e.g. lighters,
matches).
▶Do not smoke.
▶Do not use any electrical switches, mains
plugs, doorbells, telephones or other com-
munication systems in the building.
▶Close the emergency control valve or the
main isolator.
▶If possible, close the gas stopcock on the
product.
▶Warn other occupants in the building by
yelling or banging on doors or walls.
▶Leave the building immediately and ensure
that others do not enter the building.
▶Alert the police and fire brigade, and in-
form the emergency service department of
the gas supply company as soon as you
are outside the building.
1.3.2 Liquefied petroleum gas
There is a risk that liquefied petroleum gas
may collect in the lower part of multi-configur-
ation air/flue systems at floor level.
If the product is installed below ground level,
liquefied petroleum gas may accumulate at
floor level if there are any leaks.
To prevent explosions and fire:
▶Do not use liquefied petroleum gas to op-
erate the heat generator for a multi-config-
uration air/flue system operating at excess
pressure.
▶Make sure that liquefied petroleum gas
cannot escape from the product or the gas
pipe under any circumstances.
To prevent ignition problems when the lique-
fied petroleum gas tank is poorly ventilated:
▶Ensure that the liquid gas tank has been
purged properly before installing the
product.
▶If required, contact the filler or the liquid
gas supplier.
1.3.3 Flue gas
Flue gases may cause poisoning, while hot
flue gases may also cause burns. Flue gases
must therefore never be allowed to escape
uncontrollably.
What to do if you smell flue gas in the prop-
erty:
▶Open all accessible doors and windows
fully to provide ventilation.
▶Switch off the product.
▶Check the flue gas routes in the product
and the flue gas diversions.
To prevent flue gas exit:
▶Only operate the product if the air/flue pipe
has been completely installed.
▶With the exception of short periods for
testing purposes, only operate the product
when the front casing is installed and
closed.
▶In order to operate the product, ensure that
the condensate siphon is always full.
–Water seal level for units with condens-
ate siphon (third-party accessory):
≥200 mm
To ensure that the seals are not damaged:
▶Instead of grease, use only water or com-
mercially available soft soap to aid installa-
tion.
1.3.4 Air supply
Unsuitable or insufficient combustion and
room air may lead to material damage, but
also to life-threatening situations.
▶Use the data plate, to check the unit types
(air/flue gas) for which the product is ap-
proved:
–Unit type B = open-flued combustion
air supply
–Unit type C = room-sealed combustion
air supply
▶If the product has the approval for unit type
Band you want to operate the product as
open-flued, ensure that the air supply to
the product's installation room is perman-
ently unobstructed and sufficient in accord-
ance with the relevant ventilation require-
ments. This also applies, in particular, for
cupboard installations.
To prevent corrosion on the product and in
the flue system:
▶Ensure that the combustion air supply is
free from sprays, solvents, chlorinated
cleaning agents, paint, adhesives, am-
monia compounds, dust or similar sub-
stances.
▶Ensure that no chemical substances are
stored at the installation site.

6Installation and maintenance instructions 0020308118_05
▶If you are installing the product in
hairdressing salons, painter's or joiner's
workshops, cleaning businesses or similar
locations, choose a separate installation
room in which the room air is technically
free of chemical substances.
1.3.5 Air/flue pipe
The heat generators are system-certified
together with the original air/flue pipes.
▶Only use original air/flue pipes from the
manufacturer.
1.3.6 Electricity
The power supply terminals L and N remain
live.
To prevent electric shocks, proceed as fol-
lows before working 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) or remove the mains plug (if
present).
▶Secure against being switched back on
again.
▶Wait at least three minutes until the con-
densers have discharged.
▶Check that there is no voltage.
1.3.7 Weight
To prevent injuries when transporting the
product:
▶Make sure that the product is transported
by at least two people.
To prevent material damage to the flexible
gas pipe:
▶Never suspend the compact thermal
module on the flexible gas pipe.
1.3.8 Explosive and flammable substances
To prevent explosions and fire:
▶Do not use the product in rooms that con-
tain explosive or flammable substances
(such as petrol, paper or paint).
1.3.9 High temperatures
High temperatures may occur in the product
and its immediate vicinity, and may lead to
burns.
To prevent burns:
▶Always ensure that no high temperatures
are present, and only work on components
once they have cooled down sufficiently.
To prevent material damage that is caused
by heat transfer, particularly during soldering
work:
▶Before carrying out soldering work, remove
all sealing materials.
▶Separate components which may be in-
ternally damaged by heat from each other.
▶Only continue the installation processes
once all components have cooled down
(warm to the touch).
1.3.10 Heating water
Both unsuitable heating water and air in the
heating water may cause material damage to
the product and in the heat generator circuit.
▶Check the quality of the heating water.
(→Section 9.3)
▶If you use non-diffusion-tight plastic pipes
in the heating installation, ensure that no
air gets into the heat generator circuit.
1.3.11 Neutralisation device
To prevent contamination of the waste water:
▶Check whether a neutralising unit must
be installed in accordance with national
regulations.
▶Observe local regulations on neutralising
condensate.
1.3.12 Frost
To prevent material damage:
▶Do not install the product in rooms prone
to frost.
1.3.13 Safety devices
▶Install the necessary safety devices in the
installation.

0020308118_05 Installation and maintenance instructions 7
1.4 Regulations (directives, laws,
standards)
▶Observe the national regulations, stand-
ards, directives, ordinances and laws.
1.5 List of relevant standards for Great
Britain and Ireland
▶Observe the national regulations, stand-
ards, directives, ordinances and laws.
You can find a list of relevant standards at:
https://www.vaillant.co.uk/standards

8Installation and maintenance instructions 0020308118_05
2 Guarantee and Customer Service
Thank you for installing a new Vaillant appliance in your home.
Vaillant appliances are manufactured to the very highest standard so we are pleased to offer our
customers a comprehensive guarantee.
To maintain your guarantee, the boiler must be serviced annually by a competent person who
holds the required qualifications in accordance with the rules in force of the country where the
product is installed and in accordance with the manufactures recommendations.
We recommend you complete your guarantee registration as soon as possible.
Guarantee Registration
Sales Support:
Telephone: [phone]
Technical Enquiries:
Telephone: [phone]
Email: [e-mail]
General Enquiries:
Telephone: [phone]
Training Enquiries:
Telephone: [phone]
Email: [e-mail]
Spares Enquiries:
Telephone: [phone]
To register your Vaillant appliance visit:
https://self-service.vaillant.co.uk/warranty-registration
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 Regulations.
The Benchmark Checklist can be used to demonstrate compliance with Building Regulations and should be provided to the customer
for future reference.
Installers are required to carry out installation, commissioning 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.

0020308118_05 Installation and maintenance instructions 9
3 Technical data
During initial start-up, the operating data may initially deviate from the specified nominal data.
Technical data –General
VU 10 VU 15 VU 20
Designated country (designation in accordance with
ISO 3166)
GB, IE GB, IE GB, IE
Permitted gas boiler category (depending on the unit version) II2H3P II2H3P II2H3P
CE PIN 0063CU3910 0063CU3910 0063CU3910
UKCA PIN 0063CU3910 0063CU3910 0063CU3910
Gas connection, boiler side 15 mm 15 mm 15 mm
Flow/return heating connections, boiler side G 3/4 ″G 3/4 ″G 3/4 ″
Flow/return cylinder connections, boiler side –––
Domestic hot/cold water connections, boiler side –––
Expansion relief valve connection 15 mm 15 mm 15 mm
Condensate discharge hose connection 19 mm 19 mm 19 mm
Air/flue pipe connection 60/100 mm 60/100 mm 60/100 mm
Capacity of the heating expansion vessel 10 l 10 l 10 l
Pre-charge pressure of the heating expansion vessel 70 kPa
(700 mbar)
70 kPa
(700 mbar)
70 kPa
(700 mbar)
Min. flue gas temperature 35 ℃35 ℃35 ℃
Max. flue gas temperature 85 ℃85 ℃85 ℃
Approved gas boiler types C13, C33, C43,
C53
C13, C33, C43,
C53
C13, C33, C43,
C53
NOx class 666
SAP 2009/2012 annual efficiency (%) –––
Weight with packaging (incl. accessories) 37 kg 37 kg 37 kg
Weight (without packaging, without water) 34 kg 34 kg 34 kg
Weight ready for operation (filled) 37 kg 37 kg 37 kg
VU 25 VU 30 VU 35
Designated country (designation in accordance with
ISO 3166)
GB, IE GB, IE GB, IE
Permitted gas boiler category (depending on the unit version) II2H3P II2H3P I2H
CE PIN 0063CU3910 0063CU3910 0063CU3910
UKCA PIN 0063CU3910 0063CU3910 0063CU3910
Gas connection, boiler side 15 mm 15 mm 15 mm
Flow/return heating connections, boiler side G 3/4 ″G 3/4 ″G 3/4 ″
Flow/return cylinder connections, boiler side –––
Domestic hot/cold water connections, boiler side –––
Expansion relief valve connection 15 mm 15 mm 15 mm
Condensate discharge hose connection 19 mm 19 mm 19 mm
Air/flue pipe connection 60/100 mm 60/100 mm 60/100 mm
Capacity of the heating expansion vessel 10 l 10 l 10 l
Pre-charge pressure of the heating expansion vessel 70 kPa
(700 mbar)
70 kPa
(700 mbar)
70 kPa
(700 mbar)
Min. flue gas temperature 35 ℃35 ℃35 ℃
Max. flue gas temperature 85 ℃85 ℃85 ℃
Approved gas boiler types C13, C33, C43,
C53
C13, C33, C43,
C53
C13, C33, C43,
C53
NOx class 666
SAP 2009/2012 annual efficiency (%) –––
Weight with packaging (incl. accessories) 39 kg 39 kg 41 kg

10 Installation and maintenance instructions 0020308118_05
VU 25 VU 30 VU 35
Weight (without packaging, without water) 36 kg 36 kg 40.5 kg
Weight ready for operation (filled) 41 kg 41 kg 44 kg
VUW 20/26 VUW 25/32 VUW 30/36
Designated country (designation in accordance with
ISO 3166)
GB, IE GB, IE GB, IE
Permitted gas boiler category (depending on the unit version) II2H3P II2H3P II2H3P
CE PIN 0063CU3910 0063CU3910 0063CU3910
UKCA PIN 0063CU3910 0063CU3910 0063CU3910
Gas connection, boiler side 15 mm 15 mm 15 mm
Flow/return heating connections, boiler side G 3/4 ″G 3/4 ″G 3/4 ″
Flow/return cylinder connections, boiler side –––
Domestic hot/cold water connections, boiler side G 3/4 ″G 3/4 ″G 3/4 ″
Expansion relief valve connection 15 mm 15 mm 15 mm
Condensate discharge hose connection 19 mm 19 mm 19 mm
Air/flue pipe connection 60/100 mm 60/100 mm 60/100 mm
Capacity of the heating expansion vessel 10 l 10 l 10 l
Pre-charge pressure of the heating expansion vessel 70 kPa
(700 mbar)
70 kPa
(700 mbar)
70 kPa
(700 mbar)
Min. flue gas temperature 35 ℃35 ℃35 ℃
Max. flue gas temperature 85 ℃85 ℃85 ℃
Approved gas boiler types C13, C33, C43,
C53
C13, C33, C43,
C53
C13, C33, C43,
C53
NOx class 666
SAP 2009/2012 annual efficiency (%) –––
Weight with packaging (incl. accessories) 39 kg 41 kg 41 kg
Weight (without packaging, without water) 36 kg 37 kg 37 kg
Weight ready for operation (filled) 40 kg 43 kg 43 kg
VUW 30/40
Designated country (designation in accordance with
ISO 3166)
GB, IE
Permitted gas boiler category (depending on the unit version) I2H
CE PIN 0063CU3910
UKCA PIN 0063CU3910
Gas connection, boiler side 15 mm
Flow/return heating connections, boiler side G 3/4 ″
Flow/return cylinder connections, boiler side –
Domestic hot/cold water connections, boiler side G 3/4 ″
Expansion relief valve connection 15 mm
Condensate discharge hose connection 19 mm
Air/flue pipe connection 60/100 mm
Capacity of the heating expansion vessel 10 l
Pre-charge pressure of the heating expansion vessel 70 kPa
(700 mbar)
Min. flue gas temperature 35 ℃
Max. flue gas temperature 85 ℃
Approved gas boiler types C13, C33, C43,
C53
NOx class 6
SAP 2009/2012 annual efficiency (%) –
Weight with packaging (incl. accessories) 44 kg