Vaillant home combi Installation And Maintenance Instructions Manual

Installation and maintenance instructions

For the competent person

Installation and maintenance instructions

Publisher/manufacturer
Vaillant GmbH

Berghauser Str. 40 D-42859 Remscheid
Tel. [phone]‑0 Fax [phone]‑28 10
[e-mail] www.vaillant.de

HOME

COMBI

GB, IE

Contents

Contents

1 Safety .................................................................... 4

1.1 Action-related warnings......................................... 4

1.2 Risk caused by inadequate qualifications.............. 4

1.3 Intended use ......................................................... 4

1.4 General safety information .................................... 4

1.5 Regulations (directives, laws, standards) .............. 6

2 Notes on the documentation .............................. 7

2.1 Observing other applicable documents ................. 7

2.2 Storing documents................................................. 7

2.3 Applicability of the instructions .............................. 7

3 Product description............................................. 7

3.1 Serial number ........................................................ 7

3.2 Information on the identification plate.................... 7

3.3 Functional elements: Combination unit ................. 8

3.4 CE label ................................................................. 8

4 Installation............................................................ 8

4.1 Transporting the unit.............................................. 8

4.2 Unpacking the product........................................... 8

4.3 Checking the scope of delivery.............................. 8

4.4 Dimensions............................................................ 9

4.5 Minimum clearances.............................................. 9

4.6 Clearance from combustible components ............. 9

4.7 Using the installation template............................... 9

4.8 Wall-mounting the product..................................... 9

4.9 Removing/installing the front casing.................... 10

4.10 Removing/installing the side section ................... 10

5 Installation.......................................................... 10

5.1 Checking the gas meter....................................... 11

5.2 Gas and water connections ................................. 11

5.3 Connecting the drain line for the expansion

relief valve............................................................ 11

5.4 Connecting the condensate drain pipework ........ 12

5.5 Connecting the drain cock ................................... 12

5.6 Flue gas installation ............................................. 12

5.7 Electrical installation ............................................ 14

6 Operation............................................................ 15

6.1 Using diagnostics codes ...................................... 15

6.2 Displaying the status codes ................................. 16

6.3 Using check programmes .................................... 16

7 Start-up ............................................................... 16

7.1 Carrying out the initial start-up............................. 16

7.2 Checking the factory setting ................................ 16

7.3 Checking and treating the heating water/filling

and supplementary water .................................... 17

7.4 Avoiding danger arising from insufficient water

pressure............................................................... 18

7.5 Switching on the product ..................................... 18

7.6 Filling and purging the heating installation .......... 18

7.7 Filling the condensate siphon .............................. 18

7.8 Filling the hot water circuit ................................... 18

7.9 Checking and adjusting the gas settings............. 19

7.10 Checking function and leak-tightness.................. 20

8 Adapting the unit to the heating

installation.......................................................... 20

8.1 Burner anti-cycling time ....................................... 20

8.2 Setting the pump output....................................... 21

8.3 Setting the bypass ............................................... 21

9 Adjusting the hot water temperature............... 22

9.1 Setting the hot water temperature ....................... 22

10 Handing the product over to the operator ...... 22

11 Inspection and maintenance ............................ 22

11.1 Observing inspection and maintenance

intervals ............................................................... 22

11.2 Procuring spare parts .......................................... 22

11.3 Checking the CO₂ content ................................... 22

11.4 Setting the CO₂ content ....................................... 23

11.5 Removing the gas-air mixture unit....................... 23

11.6 Cleaning the heat exchanger............................... 24

11.7 Checking the burner ............................................ 24

11.8 Checking the ignition electrode ........................... 24

11.9 Cleaning the condensate tray .............................. 24

11.10 Cleaning the condensate siphon ......................... 25

11.11 Cleaning the filter in the cold water inlet .............. 25

11.12 Cleaning the heating filter .................................... 25

11.13 Installing the gas-air mixture unit......................... 26

11.14 Draining the product ............................................ 26

11.15 Checking the pre-charge pressure of the

expansion vessel ................................................. 26

11.16 Completing inspection and maintenance work .... 26

12 Troubleshooting ................................................ 26

12.1 Rectifying faults ................................................... 26

12.2 Calling up the fault memory................................. 26

12.3 Deleting the fault memory.................................... 26

12.4 Resetting parameters to factory settings ............. 26

12.5 Preparing the repair work .................................... 26

12.6 Replacing defective components......................... 26

12.7 Completing repair work........................................ 29

13 Decommissioning the product ......................... 29

14 Customer service............................................... 29

Appendix ............................................................................ 30

A Check programmes – Overview ....................... 30

B Overview of diagnostics codes........................ 30

C Status codes – Overview .................................. 34

D Overview of fault codes .................................... 35

E Connection diagram: Combination unit .......... 38

F Connection diagram: Combination unit (35

kW) ...................................................................... 39

G Inspection and maintenance work –

Overview............................................................. 40

H Opening in the air/flue pipe .............................. 41

H.1 Positioning of the opening of a fan-supported

flue gas pipe ........................................................ 41

H.2 Text from BS 5440-1 on fan-supported flue

gas pipes ............................................................. 42

H.3 Opening of the flue pipe below eaves and

balconies.............................................................. 42

I Commissioning Checklist................................. 43

2 Installation and maintenance instructions HOME 0020224355_00

J Combustion chart.............................................. 46

K Lengths of the air/flue pipe............................... 47

L Technical data.................................................... 47

Index ................................................................................... 50

Contents

0020224355_00 HOME Installation and maintenance instructions 3

1 Safety

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

– observance of accompanying operating,

installation and servicing instructions for
the product and any other system compon­ents

– installing and fitting the product in accord-

ance with the product and system approval

– compliance with all inspection and main-

tenance conditions listed in the instruc­tions.

Intended use also covers installation in ac­cordance with the IP class.

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

1.2 Risk caused by inadequate qualifications

Assembly and disassembly, installation, start­up, maintenance, repairs and decommission­ing must only be carried out by a compet­ent person who is sufficiently qualified to ob­serve all of the instructions that come with the
product, to proceed in accordance with the
current state of the art, and to comply with
all applicable directives, standards, laws and
other regulations.

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 heat generator
for closed central heating installations and for
hot water generation.

The products referred to in these instructions
must only be installed and operated in con­junction with the flue pipe accessories listed
in other applicable documents.

Exceptions: For C63 and B23P installation
types, follow the specifications in these in­structions.

Intended use includes the following:

1.4.1 Risk of death from escaping gas

What to do if you smell gas in the building:

▶ Avoid rooms that smell of gas.
▶ If possible, open doors and windows fully

and ensure adequate ventilation.

▶ Do not use naked flames (e.g. lighters,

matches).

▶ Do not smoke.
▶ Do not use any electrical switches, mains

plugs, doorbells, telephones or other com­munication systems in the building.

▶ If it is safe to do so, close the emergency

control valve or the main isolator.

▶ If possible, close the gas isolator cock 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.

▶ Notify the gas supply company or National

Grid Transco [phone] by tele­phone from outside of the building.

1.4.2 Risk of death from escaping flue gas

If you operate the product with an empty con­densate siphon, flue gas may escape into the
room air.

4 Installation and maintenance instructions HOME 0020224355_00

Safety 1

▶ In order to operate the product, ensure that

the condensate siphon is always full.

1.4.3 Risk of death due to blocked or leaking flue gas routes

Installation errors, damage, tampering, unau­thorised installation sites or similar can cause
flue gas to escape and result in a risk of pois­oning.

What to do if you smell flue gas in the prop­erty:

▶ 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.

1.4.4 Risk of death due to explosive and flammable materials

▶ Do not use or store explosive or flammable

materials (e.g. petrol, paper, paint) in the
installation room of the product.

1.4.5 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:

▶ Unplug the mains plug.
▶ Or disconnect the product from the power

supply by switching off all power supplies
(electrical partition with a contact opening
of at least 3 mm, e.g. fuse or line protec­tion switch).

▶ Secure against being switched back on

again.

▶ Wait for at least 3 minutes until the con-

densers have discharged.

1.4.6 Risk of death due to lack of safety devices

The schematic drawings included in this doc­ument do not show all safety devices re­quired for correct installation.

▶ Install the necessary safety devices in the

system.

▶ Observe the applicable national and inter-

national laws, standards and guidelines.

1.4.7 Risk of poisoning and burns caused by escaping hot flue gases

▶ 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.

1.4.8 Risk of being burned or scalded by hot components

▶ Only carry out work on these components

once they have cooled down.

1.4.9 Risk of injury during transport due to a high product weight.

▶ Make sure that the product is transported

by at least two people.

1.4.10 Risk of corrosion damage due to

unsuitable combustion and room
air

Sprays, solvents, chlorinated cleaning
agents, paint, adhesives, ammonia com­pounds, dust or similar substances may lead
to corrosion on the product and in the air/flue
pipe.

▶ Ensure that the supply of combustion air is

always free of fluorine, chlorine, sulphur,
dust, etc.

▶ Ensure that no chemical substances are

stored at the installation site.

▶ Ensure that the combustion air is not

routed through chimneys which have
previously been used with floor-standing
oil-fired boilers, or with other boilers,
which could cause soot to build up in the
chimney.

▶ 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 a combustion air supply is
ensured that is technically free of chemical
substances.

1.4.11 Risk of material damage caused by

frost

▶ Do not install the product in rooms prone

to frost.

0020224355_00 HOME Installation and maintenance instructions 5

1 Safety

1.4.12 Risk of material damage caused by using an unsuitable tool

▶ Use the correct tool to tighten or loosen

screw connections.

1.5 Regulations (directives, laws,

standards)

▶ Observe the national regulations, stand-

ards, guidelines and laws.

6 Installation and maintenance instructions HOME 0020224355_00

Notes on the documentation 2

2

1

2 Notes on the documentation

2.1 Observing other applicable documents

▶ You must observe all the operating and installation in-

structions included with the system components.

2.2 Storing documents

▶ Pass these instructions and all other applicable docu-

ments on to the system operator.

2.3 Applicability of the instructions

These instructions apply only to:

Product article number

Article number Gas Council Num-

ber

HOME COMBI 25

-A (H-GB)

HOME COMBI 30

-A (H-GB)

HOME COMBI 35

-A (H-GB)

These products are only designed for natural gas systems.

0010019930 47-044-62

0010019931 47-044-63

0010019932 47-044-64

3 Product description

3.1 Serial number

The serial number can be found on the identification plate (1)
(→ Page 7).

Stickers showing the serial number are on the back of the
electronics box (2).

3.2 Information on the identification plate

The identification plate is mounted on the underside of the
product in the factory.

The identification plate keeps record of the country in which
the product is to be installed.

Information on the
identification plate

Serial number For quality control purposes; 3rd and 4th

HOME COMBI Product description

XX, Gxx – xx mbar
(x kPa)

Cat. Approved gas category

Condensing techno­logy

Type: Xx3(x) Permissible flue gas connections

PMS Maximum water pressure in heating

PMW Maximum water pressure in hot water

V/Hz Electric connection

W Max. electrical power consumption

IP Level of protection

Pn Nominal heat output range in heating

Pnc Nominal heat output range in heating

P Nominal heat output range in hot water

Qn Nominal heating load range in heating

Qnw Nominal heating load range in hot water

T

max.

NOx NOx class for the product

Code (DSN) Specific product code

GC no. Gas council number

Meaning

digits = year of production

For quality control purposes; 5th and 6th
digits = week of production

For identification purposes; 7th to 16th
digits = product article number

For quality control purposes; 17th to 20th
digits = place of manufacture

Gas group and gas connection pressure
as set at the factory

Efficiency class of the boiler in accord­ance with EC Directive 92/42/EEC

mode

handling mode

Heating mode

Hot water generation

mode

mode (condensing technology)

handling mode

mode

handling mode

Max. flow temperature

→ "CE label" section

Read the instructions.

→ "Recycling and disposal" section

Information on the
identification plate

0020224355_00 HOME Installation and maintenance instructions 7

Meaning

Barcode with serial number

4 Installation

14

12

11

10

8

9

7

5

6

4

3

2

1

16

15

18 17

13

3.3 Functional elements: Combination unit

4 Installation

4.1 Transporting the unit

Important: With regard to the regulations of 1992 concern-

ing the manual handling of loads, the unit exceeds the
weight that can be lifted by a single person.

4.1.1 General

▶ Hold the load as close as possible to your body. Avoid

rotational movements. Instead, reposition your feet.

▶ If the unit is being lifted by two persons, ensure your

movements are coordinated during lifting.

▶ Avoid bending your upper body – do not lean forwards or

to the side.

▶ Wear suitable non-slip protective gloves in order to pro-

tect your hands against sharp edges. Ensure that you are
carrying the load securely.

▶ If required, get somebody to assist you in this.

4.1.2 Unloading the box from the delivery van

▶ It is recommended that two people lift the unit together.
▶ Lift the box using the straps provided.
▶ Use safe lifting techniques – keep your back straight and

bend your legs at the knee.

▶ Hold the load as close as possible to your body.
▶ If the unit is being lifted by two persons, ensure your

movements are coordinated during lifting.

▶ If required, get somebody to assist you in this.

4.2 Unpacking the product

1. Remove the product from its box.

1 Electronics box

2 Heating circuit expan-

sion relief valve

3 Plate heat exchanger

4 Condensate siphon

5 Flue pipe

6 Pressure sensor

7 Flue gas analysis point

8 Ignition transformer

9 Gas valve

3.4 CE label

The CE label shows that the products comply with the basic
requirements of the applicable directives as stated on the
identification plate.

The declaration of conformity can be viewed at the manufac­turer's site.

10 Air intake pipe

11 Ignition electrode

12 Fan

13 Primary heat exchanger

14 Heating expansion

vessel

15 Volume flow sensor

16 Heating pump

17 Bypass

18 3-way valve

2. Remove the protective film from all of the product's
components.

4.3 Checking the scope of delivery

▶ Check that the scope of delivery is complete.

Quantity Description

1

1

1 Enclosed documentation

Heat generator

Bag with accessories

– Bag with seals
– Condensate drain hose
– Drain spigot of the expansion relief valve
– Installation template
– Hanging bracket
– Bag containing the hydraulic connections

8 Installation and maintenance instructions HOME 0020224355_00

Installation 4

A

C

B

D

A A

D

BC

A

B

4.4 Dimensions

4.6 Clearance from combustible components

It is not necessary to maintain a clearance between the
product and components made of combustible materials.

4.7 Using the installation template

▶ Use the installation template to ascertain the locations at

which you need to drill holes and make breakthroughs.

4.8 Wall-mounting the product

1. Check whether the wall has sufficient load-bearing ca­pacity to bear the operational weight of the product.

2. Wall-mount the product as described using the adapted
fixing material provided on-site.

Conditions: The load-bearing capacity of the wall is sufficient, The fixing

material may be used for the wall

Dimensions

A B C D

740 mm 130 mm 300 mm 418 mm

4.5 Minimum clearances

Minimum clearances

A B C D D

≥ 0 mm ≥ 300 mm ≥ 300 mm ≥ 600 mm ≥ 5 mm

▶ Wall-mount the product as described.

Conditions: The load-bearing capacity of the wall is not sufficient

▶ Ensure that wall-mounting apparatus on-site has a suf-

ficient load-bearing capacity. Use individual stands or
primary walling, for example.

▶ Do not wall-mount the product if you cannot provide

wall-mounting apparatus with a sufficient load-bearing
capacity.

Note

Cabinet­type cas­ing

0020224355_00 HOME Installation and maintenance instructions 9

5 Installation

B

C

A

1

1

2x

1

A

B

C

D

4.9 Removing/installing the front casing

4.9.1 Removing the front casing

1. Undo the two screws (1).

2. Gently press the front casing backwards in the centre
so that the latching lug is released.

3. Pull the front casing forwards at the bottom edge.

4. Lift the front casing upwards from the bracket.

4.9.2 Fitting the front panel

▶ Refit the components in the reverse order.

4.10 Removing/installing the side section

4.10.1 Removing the side section

Caution.
Risk of material damage caused by mech-

anical deformation.

Removing both side sections may cause
mechanical distortion in the product, which
may cause damage to the piping, for ex­ample, and potentially result in leaks.

▶ Always remove only one side section –

never both side sections at the same time.

Note

If there is sufficient lateral clearance (at least 50
mm), you can remove the side section to facilitate
maintenance or repair work.

1. Tilt the electronics box forward.

2. Hold on to the side section so that it cannot fall and
unscrew both screws (1), one from the top and one
from the bottom.

3. Tilt the side section to the outside and move it down­wards and out.

4.10.2 Installing the side section

▶ Refit the components in the reverse order.

5 Installation

Danger!
Risk of explosion or scalding caused by

incorrect installation.

Stresses in the supply line can cause leaks.

▶ Make sure there is no voltage in the sup-

ply lines when they are installed.

Caution.
Risk of damage caused by contaminated

lines.

Foreign bodies, such as welding remnants,
sealing residue or dirt in the water pipes, may
cause damage to the boiler.

▶ Flush the heating installation thoroughly

prior to installation.

10 Installation and maintenance instructions HOME 0020224355_00

5.1 Checking the gas meter

1

2

3

4

5

1

▶ Make sure that the existing gas meter is capable of

passing the rate of gas supply required.

5.2 Gas and water connections

Caution.
Risk of damage caused by incorrect gas

connection installation.

Excess test pressure or operating pressure
may cause damage to the gas valve.

▶ Check the leak-tightness of the gas valve

using a maximum pressure of 1.1 kPa
(110 mbar).

Caution.
Risk of damage caused by corrosion.

If non-diffusion-tight plastic pipes are used in
the heating installation, this may cause air to
enter the heating water and corrosion of the
heat generation circuit and the boiler.

▶ If using non-diffusion-tight plastic pipes

in the heating installation, separate the
system by installing an external heat ex­changer between the boiler and the heat­ing installation.

Installation 5

1 Heating flow connec-

tion, G3/4

2 Hot water connection,

G3/4

3 Gas connection, G1/2

1. Connect the water and gas connections in accordance
with the applicable standards.

2. Purge the gas line before start-up.

3. Check whether the connections (→ Page 20) are leak­tight.

5.3 Connecting the drain line for the expansion

relief valve

4 Connection for the cold

water supply line, G3/4

5 Heating return connec-

tion, G3/4

Caution.
Risk of material damage due to heat trans-

fer during soldering.

▶ Do not solder the connection pieces if

the connection pieces are screwed to the
service valves.

Note

We recommend that you provide the water pipes
to the boiler outlet and to the system with thermal
insulation.

Preliminary work

1. Check that the system volume and the volumetric capa­city of the expansion vessel are the same.

▽ If the volume of the expansion vessel is insufficient

for the system.

▶ Install an additional expansion vessel in the

heating return, as close to the product as pos­sible.

▶ Install a non-return flap at the product's outlet

(heating flow).

2. Ensure that the system has the following components:

– A stop cock in the cold water supply
– A stop cock in the gas line
– A filling and draining device in the heating installa-

tion

▶ Ensure that the pipeline is visible.
▶ The pipe must have a continuous fall and be routed to a

position so that any discharge of water, possibly boiling,
or steam cannot create any danger to persons, damage
to property or external electrical components and wiring.

◁ The components must be set up in such a way that

you can see the water flowing out.

0020224355_00 HOME Installation and maintenance instructions 11

5 Installation

1

2

3

2

1

A

B

C

5.4 Connecting the condensate drain pipework

▶ Follow the instructions listed here and observe any legal

directives and local regulations on condensate discharge.

▶ Use PVC or another material that is suitable for draining

the non-neutralised condensate.

▶ If you cannot guarantee that the materials from which

the drain lines are made are suitable, install a system for
neutralising the condensate.

▶ Ensure that the connection between the condensate

drain pipework and the drain hose is not air-tight.

Note

The condensate drain pipework must have a
continuous fall (45 mm per metre) and should
whenever possible terminate at a suitable
drain point within the heated envelope of the
building that will remain frost free under long
periods of low external temperatures.

5.5 Connecting the drain cock

▶ Connect a hose to the drain cock (1) and guide the free

end of the hose to a suitable outflow location.

5.6 Flue gas installation

5.6.1 Replacing the connection piece for the air/flue pipe

Note

As standard, the product is equipped with a con­nection piece with a diameter of 60/100 mm.

▶ Connect the condensate siphon (1). Use the supplied

drain hose (2) for this.

▶ Connect condensate drain pipework (21.5 mm, not in-

cluded in the scope of delivery) (3) to the drain hose (2).

▶ During installation remove all burs from inside of cut pipe

work and avoid excessive adhesive which may trap small
pockets of water close to the pipe wall which can freeze
and build into a larger ice plug.

▶ As with other pipe work insulate the condensate dis-

charge pipe to minimise any risk of freezing and beware
when crossing cavities that the fall is maintained and the
pipe sleeved.

You can find further information in BS 6789: "Specification
for installing and maintaining gas-fired boilers with a nominal
heat loading less than 70 kW".

1. Insert a screwdriver into the slot between the measuring

stub pipes.

2. Push in the screwdriver carefully (A).

3. Turn the connector anticlockwise (B) as far as it will go

and then remove it by pulling it upwards (C).

4. Insert a new connector. In doing so, pay attention to the

latching lugs.

5. Turn the connection piece clockwise so that it clicks into

position.

5.6.2 Installing the air/flue pipe

Caution.
Risk of poisoning due to escaping flue

gas.

Mineral-oil-based greases can damage the
seals.

▶ Instead of grease, use only water or com-

mercially available soft soap to aid install­ation.

12 Installation and maintenance instructions HOME 0020224355_00

50 mm/1m

5 %

1. Ensure that there is a minimum downward gradient

L

L

L

of 5% between the elbow and the terminal on the
air/flue pipe so that the condensate can flow back to the
product.

2. Install the flue gas pipe in accordance with the installa­tion instructions that are included in the scope of deliv­ery for the air/flue pipe.

3. You can find out which air/flue pipes may be used by
consulting the enclosed air/flue pipe installation manual.

4. Install the flue gas pipe in accordance with the installa­tion instructions that are included in the scope of deliv­ery for the air/flue pipe.

5.6.3 Air/flue gas system

5.6.3.1 Horizontal air/flue gas system

Installation 5

5.6.3.2 Vertical air/flue gas system

The openings in an attachment for separate lines must lead
to a 50 cm-sided square.

For each additional 90° elbow (or two 45° elbows) that is
required, the length (L) must be reduced by 1 m.

Length of the C33 type flue pipe (→ Page 47)

5.6.3.3 Air/flue gas system for header lines

The openings in an attachment for separate lines must lead
to a 50 cm-sided square.

For each additional 90° elbow (or two 45° elbows) that is
required, the length (L) must be reduced by 1 m.

Length of the C13 type flue pipe (→ Page 47)

The connections with the line are established using the ac­cessory specially developed by the product manufacturer.

A boiler that is connected to a type C43 system must only be
connected to natural draught chimneys.

The condensate from header line systems must not drain
into the boiler.

For each additional 90° elbow (or two 45° elbows) that is
required, the length (L) must be reduced by 1 m.

Length of the C43 type flue pipe (→ Page 47)

0020224355_00 HOME Installation and maintenance instructions 13

5 Installation

B

B

A

230V

24V / eBus

30 mm max.

1

5.7 Electrical installation

Danger!
Risk of death from electric shock!

The mains connection terminals L and N re­main live even if the product is switched off:

▶ Switch off the power supply.
▶ Secure the power supply against being

switched on again.

5.7.1 Opening and closing the electronics box

5.7.3 Carrying out the wiring

1. Shorten the connection cables to the appropriate
lengths to prevent them from causing damage inside
the electronics box.

2. Screw the plug to the connection cable.

3. Plug the plug into the slot provided on the PCB.

5.7.4 Establishing the power supply

1. To open the electronics box, follow the instructions in
the specified sequence.

2. To close the electronics box, follow the instructions in
reverse order.

5.7.2 Cable route

1 24-V eBUS cable route

2 230-V eBUS cable

route

1. Observe all relevant regulations.

– The applicable regulations state that the connection

must be made via an electrical partition with a con­tact opening of at least 3 mm at each pole.

2. Make sure that the rated voltage of the mains is 230 V.

3. Provide one common electricity supply for the boiler
and for the corresponding controller:

– Power supply: Single-phase, 230 V, 50 Hz
– Fuse protection: ≤ 3 A

4. Open the electronics box.

5. Observe the routing of the power supply cable (1) in the
electronics box in order to guarantee the strain relief.

14 Installation and maintenance instructions HOME 0020224355_00

≤ 30 mm

NL

X1
230V~

RT

6. Carry out the wiring. (→ Page 14)

X2

X22

X41

–

+

24V=

RT BUS

Burner

off

X106

BUS24 V

BUSRTB.off

B
ur
ner

off

R
T

24V

=

-

+

B
U
S

1

4

32

≤ 30 mm

NL

X1
230V~

RT

7. Close the electronics box.

8. Screw the supplied plug to a three-core mains connec­tion cable that complies with the relevant standards.

9. Connect the plug for the mains connection cable.

10. Make sure that access to the mains connection is al-

ways freely available and is not covered or blocked by
an obstruction.

5.7.5 Connecting controllers to the electronic

system

Operation 6

Conditions: If installing a multi-circuit controller.

▶ Change the pump operating mode (d.18) from Eco (in-

termittent pump operating mode) to Comfort (continuous
pump operating mode).

Conditions: If you are connecting a controller (230 V).

▶ Connect the controller to the main plug.
▶ Remove the bridge from the plug 24V=RT.

4. Close the electronics box.

6 Operation

6.1 Using diagnostics codes

You can use the parameters marked as adjustable in the
table of diagnostics codes to adapt the product to the system
and customer requirements.

Overview of diagnostics codes (→ Page 30)

6.1.1 Activating diagnostics codes

1.

Press and hold the button for 7 seconds.

◁

is shown in the display.

2.

Press the or button to set the value.

◁ The access code (96) is reserved for the competent

person.

◁ The access code (35) is reserved for the customer

service.

3.

Press the button to confirm.

◁

is shown in the display.

6.1.2 Setting a diagnostics code

1.

Press the or button to select the diagnostics
code.

2.

Press the button to confirm.

◁ The value and/or status of the diagnostics code is

shown in the display.

3.

Press the or button to set the value.

3 eBUS controller or radio

receiver unit

4 Outside temperature

sensor, wired

4. If you allow the value to flash for three seconds, the
setting is automatically confirmed.

◁

is shown in the display for 1 second.

Note

You can manually confirm the setting at any
time by pressing and holding the button
for less than 3 seconds.

1 Safety thermostat for

floor-standing heating

2 24 V controller

1. Open the electronics box.

2. Carry out the wiring. (→ Page 14)

3. Connect the individual components depending on the
type of installation.

0020224355_00 HOME Installation and maintenance instructions 15

7 Start-up

5. Proceed accordingly for all parameters that need to be
changed.

6.

Press and hold the button for 3 seconds to finish
configuring the diagnostics codes.

◁ The display switches to the basic display.

6.2 Displaying the status codes

The status codes display the product's current operating
status.

Status codes – Overview (→ Page 34)

6.2.1 Activating the status codes display

1.

Hold the button down for more than 7 seconds.

◁ S.XX is shown on the display, followed by the heat-

ing flow temperature, the internal system pressure
and the cylinder temperature (depending on the ver­sion).

2.

Press the button to exit this menu.

◁ The display switches to the basic display.

6.3 Using check programmes

By activating various check programmes, you can trigger
various special functions on the product.

Check programmes – Overview (→ Page 30)

6.3.1 Calling up the check programmes

1.

Hold the button down for more than 5 seconds.

◁ All symbols are shown in the display.
◁

is shown in the display.

2.

Press and hold the button for five seconds.

◁

3.

Press the or button to select the check
programme.

4.

Press the button to confirm.

is shown in the display.

◁ on is shown in the display and the programme

starts.

5.

Press the and buttons at the same time whilst
running a check programme.

◁ The heating water temperature and the filling pres-

sure for the heating installation are shown altern­ately in the display.

6.

Press the button to return to the check programme.

◁ The display shows the check programme.

7.

Press the button to finish the check programme.

◁ OFF is shown in the display.

8.

Press and hold the button for 3 seconds to finish
the check programmes.

◁ End is shown in the display.
◁ The display switches to the basic display.

Note

If you do not press any button for 15 minutes,
the current programme is automatically can­celled and the basic display is shown.

6.3.2 Displaying the pressure and temperature of the heating during a check programme

1.

Press the buttons simultaneously.

◁ Display the filling pressure in the heating installation.
◁ Display the heating flow temperature.

2.

Press the button to display the check programme
currently running.

7 Start-up

7.1 Carrying out the initial start-up

Initial start-up must be carried out by a customer service
technician or an authorised competent person using the first­commissioning-checklist. The first-commissioning-checklist
in the appendix (→ Page 43) of the installation instructions
must be filled in and stored carefully along with the unit's
documentation.

▶ Carry out the initial start-up using the first-commission-

ing-checklist in the appendix.

▶ Fill out and sign the first-commissioning-checklist.

7.2 Checking the factory setting

Caution.
Risk of material damage caused by mak-

ing unauthorised settings.

▶ Never modify the factory setting of the gas

pressure regulator of the gas valve.

The product combustion is checked on-site and pre-set to
the type of gas specified on the identification plate.

▶ Check the information about the type of gas indicated on

the identification plate and compare this with the type of
gas available at the installation location.

Conditions: The product model is not compatible with the local gas type.

▶ Do not start up the product.

Conditions: The product model is compatible with the local gas type.

▶ Proceed as described below.

16 Installation and maintenance instructions HOME 0020224355_00

Start-up 7

7.3 Checking and treating the heating water/filling and supplementary water

Caution.
Risk of material damage due to poor-qual-

ity heating water

▶ Ensure that the heating water is of suffi-

cient quality.

▶ Before filling or topping up the system, check the quality

of the heating water.

Checking the quality of the heating water

▶ Remove a little water from the heating circuit.
▶ Check the appearance of the heating water.
▶ If you ascertain that it contains sedimentary materials,

you must desludge the system.

▶ Use a magnetic rod to check whether it contains mag-

netite (iron oxide).

▶ If you ascertain that it contains magnetite, clean the sys-

tem and apply suitable corrosion-protection measures, or
fit a magnet filter.

▶ Check the pH value of the removed water at 25 °C.
▶ If the value is below 6.5 or above 8.5, clean the system

and treat the heating water.

▶ Ensure that oxygen cannot get into the heating water.

(→ Page 20)

Checking the filling and supplementary water

▶ Before filling the system, measure the hardness of the

filling and supplementary water.

Treating the filling and supplementary water

▶ Observe all applicable national regulations and technical

standards when treating the filling and supplementary
water.

Provided the national regulations and technical standards
do not stipulate more stringent requirements, the following
applies:

You must treat the heating water in the following cases:

– If the entire filling and supplementary water quantity dur-

ing the operating life of the system exceeds three times
the nominal volume of the heating installation, or

– If the guideline values listed in the following table are not

met, or

– if the pH value of the heating water is less than 6.5 or

more than 8.5.

Total
heating
output

kW

< 50 < 300 < 3 200 2 2 0.02

> 50
to ≤ 200

> 200
to ≤ 600

> 600 2 0.02 2 0.02 2 0.02

1) Nominal capacity in litres/heating output; in the case of multi­boiler systems, the smallest single heating output is to be used.

Water hardness at specific system volume

≤ 20 l/kW

ppm

CaCO₃

200 2 150 1.5 2 0.02

150 1.5 2 0.02 2 0.02

mol/m³ppm

> 20 l/kW
≤ 50 l/kW

CaCO₃

> 50 l/kW

mol/m³ppm

CaCO₃

1)

mol/

m³

Caution.
The use of unsuitable heating water may

cause aluminium corrosion and a result­ing lack of leak-tightness.

In contrast to steel, grey cast iron or copper,
for example, aluminium reacts with alkaline
heating water (pH value > 8.5) to produce
substantial corrosion.

▶ When using aluminium, make sure that

the pH value of the heating water is
between 6.5 and a maximum of 8.5.

Caution.
Risk of material damage if the heating

water is treated with unsuitable additives.

Unsuitable additives may cause changes in
the components, noises in heating mode and
possibly subsequent damage.

▶ Do not use any unsuitable frost and cor-

rosion protection agents, biocides or seal­ants.

No incompatibility with our products has been detected to
date with proper use of the following additives.

▶ When using additives, follow the manufacturer's instruc-

tions without exception.

We accept no liability for the compatibility of any additive or
its effectiveness in the rest of the heating system.

Additives for cleaning measures (subsequent
flushing required)

– Fernox F3
– Sentinel X 300
– Sentinel X 400

Additives intended to remain permanently in the
system

– Fernox F1
– Fernox F2
– Sentinel X 100
– Sentinel X 200

Additives for frost protection intended to remain
permanently in the system

– Fernox Antifreeze Alphi 11
– Sentinel X 500

▶ If you have used the above-mentioned additives, inform

the operator about the measures that are required.

▶ Inform the operator about the measures required for frost

protection.

0020224355_00 HOME Installation and maintenance instructions 17

7 Start-up

1

1

C

2

3

1

A

B

7.4 Avoiding danger arising from insufficient water pressure

The filling pressure must be between 0.10 and 0.15 MPa
(1.0 and 1.5 bar).

Note

If the heating flow temperature is shown in the
display, press and hold the and buttons
at the same time for longer than five seconds, or
temporarily deactivate heating mode in order to
display the pressure.

If the heating installation extends over several storeys,
higher filling pressures may be required to avoid air entering
the heating installation.

If the water pressure falls below 0.05 MPa (0.5 bar), the
value flashes in the display.

If the water pressure falls below 0.03 MPa (0.3 bar), the
product switches off. The display shows 0.0 MPa (0.0 bar).
Fault F22 will be stored in the fault list.

▶ Top up the water in the heating installation to start up the

product again.

◁ The pressure value flashes in the display until a

pressure of 0.05 MPa (0.5 bar) or higher has been
reached.

◁ An automatic air vent function is activated if the

pressure exceeds 0.05 MPa (0.5 bar) for longer than
15 seconds.

4. Purge each radiator until the water escapes normally,
and then retighten the system's purging valves.

5. Check that all connections are leak-tight.

Conditions: If the noise persists in the boiler

▶ Purge the product again by activating check programme

(P.07) and then (P.06).
Check programmes – Overview (→ Page 30)

7.7 Filling the condensate siphon

7.5 Switching on the product

▶ Switch on the product via the main switch installed on-

site.

7.6 Filling and purging the heating installation

Preliminary work

▶ Flush the heating installation through.

1. Check the silicone hose connection (1) between the
pump's automatic air vent and the hydraulic console.

2. Remove the caps from the automatic air vents.

3. Fill with water until the required filling pressure is
reached.

– Recommended filling pressure: 1 … 1.5 bar

◁ The heating and hot water functions cannot be activ-

ated.

◁ The pressure value flashes in the display until a

pressure of 0.05 MPa (0.5 bar) or higher has been
reached.

1. Unclip the lower section of the siphon (1) from the up­per section of the siphon (2).

2. Remove the float (3).

3. Fill the lower section of the siphon with water up to 10
mm below the upper edge of the condensate drain pipe­work.

4. Re-insert the float (3).

Note

Check that the float is present in the con­densate siphon.

5. Clip the lower section of the siphon (1) into the upper
section of the siphon (2).

7.8 Filling the hot water circuit

1. Open the water tap to fill the hot water circuit.

2. Close the water tap once the appropriate volume of
water has flowed out.

◁ The hot water circuit is filled.

3. Check all connections and the entire system for leak­tightness.

18 Installation and maintenance instructions HOME 0020224355_00

Start-up 7

1

2

7.9 Checking and adjusting the gas settings

Only a qualified competent person is authorised to imple­ment the settings on the gas valve.

Each destroyed seal must be restored.

The CO2 adjusting screw must be sealed.

Never modify the factory setting of the gas pressure regu­lator of the gas valve.

7.9.1 Checking the gas connection pressure (gas flow pressure)

1. Ensure that the gas inlet working pressure can be

obtained with all other gas appliances in the property
working.

2. Close the gas isolator cock.

3. Undo the sealing screw on the measuring nipple (2).

4. Connect a pressure gauge to the measuring nipple (2).

5. Open the gas isolator cock.

6. Start up the product with check programme P.01.

7. In addition, ensure that maximum heat can be dissip-

ated into the heating system by turning up the room
thermostat.

8. With the boiler operating at full load check that the gas

inlet working pressure at the reference test point (2)
complies with the requirements.

Permissible connection pressure

Great Bri­tain

9. Should the pressure recorded at the reference test point

in the boiler be lower than indicated check if there is
any blockage in the pipework or if the pipework is un­dersized.

Conditions: Gas flow pressure not in the permissible range

Natural gas G20

1.7 … 2 kPa

(17.0
… 20 mbar)

Caution.
Risk of material damage and operating

faults caused by incorrect gas connec­tion pressure.

If the gas connection pressure lies outside
the permissible range, this can cause oper­ating faults in and damage to the product.

▶ Do not make any adjustments to the

product.

▶ Do not start up the product.

▶ If you cannot correct the failure, notify the gas supply

company and proceed as follows:

▶ End check programme P.01.
▶ Allow the boiler to cool down by allowing pump overrun

to operate for a minimum of two minutes.

▶ Close the gas isolator cock.

▶ Remove the pressure gauge and retighten the sealing

screw (2) for the measuring nipple.

▶ Open the gas isolator cock (1).
▶ Check the measuring nipple for gas tightness.
▶ Close the gas isolator cock (1).
▶ Fit the front panel. (→ Page 10)
▶ Disconnect the product from the power mains.
▶ You must not start up the boiler.

Conditions: Gas flow pressure in the permissible range

▶ End the check programme P.01.
▶ Allow the boiler to cool down allowing pump overrun to

operate for a minimum of two minutes.

▶ Close the gas isolator cock (1).
▶ Remove the pressure gauge and retighten the sealing

screw (2) for the measuring nipple.

▶ Open the gas isolator cock (1).
▶ Check the measuring nipple for gas tightness.
▶ Fit the front panel. (→ Page 10)
▶ Reset boiler controls for normal operation.
▶ Record the appliance gas inlet working pressure (kPa

resp. mbar) in the Benchmark gas boiler commissioning
checklist.

7.9.2 Checking the leak-tightness of the flue gas system and for flue gas recirculation

1. Check that the flue gas system is intact, in accordance

with British Gas TB 200.

2. If the flue gas installation is longer than 2 m, a flue gas

recirculation test is strongly recommended. This test
must be carried out in accordance with the instructions
below.

3. Use the air analysis point (1) to check for flue gas recir-

culation.

4. Use the flue gas measuring instrument.

5. If you discover CO or CO2 in the fresh air, search for a

leak in the flue gas system or for the flue gas recircula­tion.

6. Eliminate the damage.

7. Repeat the above-mentioned test to determine if the

fresh air contains CO or CO2.

8. If you cannot eliminate the damage, you must not start

up the boiler.

7.9.3 Thoroughly flushing the heating installation
("hot")

1. Operate the appliance until the boiler and the heating

system are up to temperature.

2. Check the heating system for leaks.

3. Connect a hose to the drain valve located at the lowest

position of the heating system.

4. Shut off the boiler, open the drain valve and all purge

valves on the radiators and allow the water to flow out
of the heating system and the boiler quickly and fully.

5. Close the drain valve.

6. Fill and purge the heating installation. (→ Page 18)

7. Re-fill the system until the system design pressure of

0,1 MPa (1,0 bar) is attained.

0020224355_00 HOME Installation and maintenance instructions 19

8 Adapting the unit to the heating installation

1

Note

The actual reading on the digital pressure
gauge should ideally be 0,05 MPa (0,5 bar)
plus an additional pressure corresponding
to the highest point of the system above the
base of the boiler – 10 m head equals an ad­ditional 1 bar reading on the pressure gauge.
The minimum pressure should not be less
than 0,1 MPa (1 bar) in any installation. If
the system is to be treated with an inhibitor it
should be applied at this stage in accordance
with the manufacturer’s instructions. Further
information can be obtained from Sentinel,
Betz Dearborn Ltd., Tel: [phone], or
Fernox, Alpha– Fry technologies. Tel: 0870

8700362.

8. Fit the front panel. (→ Page 10)

7.9.4 Checking the CO₂ content

1. Start up the product with the check programme (P.01)
and set the value.

– Setting value for the programme P.01: 100
Check programmes – Overview (→ Page 30)

2. Wait until the value that is read is stable.
– Waiting period for reading a stable value: 5 min

7.10 Checking function and leak-tightness

Before you hand the product over to the operator:

▶ Check the gas line, the flue gas installation, the heating

installation and the hot water pipes for leaks.

▶ Check that the air/flue pipe and condensate drain pipe-

work have been installed correctly.

▶ Check that the front casing has been installed correctly.

7.10.1 Checking the heating mode

1. Activate the heating mode on the user interface.

2. Turn all thermostatic radiator valves on the radiators
until they are fully open.

3. Allow the product to operate for at least 15 minutes.

4. Purge the heating installation.

5. Activate the display for the current operating status.
(→ Page 16)

Status codes – Overview (→ Page 34)

◁ If the product is working correctly, the display shows

S.04.

7.10.2 Checking the hot water generation

1. Activate the hot water handling mode on the user inter­face.

2. Open a hot water valve completely.

3. Activate the display for the current operating status.
(→ Page 16)

Status codes – Overview (→ Page 34)

◁ If the product is working correctly, the display shows

S.14.

3. Unscrew the cover from the flue gas analysis point (1).

4. Measure the CO₂ content at the flue gas analysis point

(1).

5. Compare the measured value with the corresponding
value in the table.

Checking the CO₂ content

Great Bri­tain

Removed
front cas­ing/installed
front casing

Natural gas

G20

9.2 ±1 %

◁ The value is OK.
▽ The value is not OK; you cannot start up the

product.

▶ Inform Customer Service.

8 Adapting the unit to the heating

installation

You can reset/change the system parameters (section "Us­ing diagnostics codes").

Overview of diagnostics codes (→ Page 30)

8.1 Burner anti-cycling time

To prevent frequent switching on and off of the burner and
thus prevent energy losses, an electronic restart lockout
is activated for a specific period each time the burner is
switched off. The burner anti-cycling time is only active for
the heating mode. Hot water handling mode during a burner
anti-cycling time does not affect the time function element.

8.1.1 Setting the maximum burner anti-cycling time

1. Set the diagnostics code. (→ Page 15)

Overview of diagnostics codes (→ Page 30)

2. If required, adjust the maximum burner anti-cycling time

using the diagnostics code d.02.

20 Installation and maintenance instructions HOME 0020224355_00

Adapting the unit to the heating installation 8

21

3

4

60

70

50

30

20

40

10

0 500 1000 1500 A

B

21

34

60

70

50

30

20

40

10

0 500 1000 1500 A

B

21

34

60

70

50

30

20

40

10

0 500 1000 1500 A

B

1

8.1.2 Resetting the remaining burner anti-cycling time

▶

Hold the button down for more than 3 seconds.

◁

is shown in the display.

8.2 Setting the pump output

Conditions: Modulating pump

The product is equipped with a speed-regulated high-effi­ciency pump, which adjusts independently to the hydraulic
conditions of the heating installation.

If the heating installation is equipped with a low loss header,
switch off the speed control and set the pump output to a
fixed value.

▶ If required, use diagnostics code d.14 to adjust the set-

ting for the operating-mode-dependent pump speed.

▶ Set the diagnostics code. (→ Page 15)

Overview of diagnostics codes (→ Page 30)

Flow rate-pressure curves for 25 kW
(pressure measured downstream of the valves)

4 Flow rate at maximum

output (ΔT = 20K)

A Throughput in circuit

(l/h)

B Available pressure

(kPa)

Flow rate-pressure curves for 35 kW
(pressure measured downstream of the valves)

1 Maximum speed (by-

pass closed)

2 Maximum speed (de-

fault setting for the by­pass)

3 Minimum speed (default

setting for the bypass)

4 Flow rate at maximum

output (ΔT = 20K)

A Throughput in circuit

(l/h)

B Available pressure

(kPa)

1 Maximum speed (by-

pass closed)

2 Maximum speed (de-

fault setting for the by­pass)

3 Minimum speed (default

setting for the bypass)

4 Flow rate at maximum

output (ΔT = 20K)

A Throughput in circuit

(l/h)

B Available pressure

(kPa)

Flow rate-pressure curves for 30 kW
(pressure measured downstream of the valves)

8.3 Setting the bypass

Conditions: Modulating pump

If the pump operating parameter d.14 is set to Auto (∆p
limit), the default setting must not be changed.

Caution.
Risk of material damage caused by incor-

rect setting of the high-efficiency pump

When the pressure at the bypass valve is
increased (turning clockwise), malfunctions
may occur if the pump output is set below
100%.

▶ In this case, set the pump output to

5 = 100% using diagnostics parameter
d.14.

1 Maximum speed (by-

pass closed)

2 Maximum speed (de-

fault setting for the by­pass)

0020224355_00 HOME Installation and maintenance instructions 21

3 Minimum speed (default

setting for the bypass)

▶ Regulate the pressure using the adjusting screw (1).
▶ Fit the front panel. (→ Page 10)

9 Adjusting the hot water temperature

1

Position of the adjusting
screw

Right-hand stop (screwed
all the way in)

Mid-position (six anti­clockwise rotations)

Five further anti-clockwise
rotations starting from the
mid-position

Notes/application

If the radiators do not heat
up sufficiently at the default
setting. In this case, you must
set the pump to the maximum
speed.

Default setting

If noises are produced in the
radiators or radiator valves.

9 Adjusting the hot water temperature

You can reset/change the system parameters (→ section
"Using diagnostics codes").

Overview of diagnostics codes (→ Page 30)

9.1 Setting the hot water temperature

Danger!
Risk of death from Legionella.

Legionella multiply at temperatures below
60 °C.

▶ Ensure that the operator is familiar with all

of the Anti-legionella measures in order
to comply with the applicable regulations
regarding legionella prevention.

11 Inspection and maintenance

11.1 Observing inspection and maintenance intervals

▶ Adhere to the minimum inspection and maintenance in-

tervals. Depending on the results of the inspection, it may
be necessary to bring maintenance work forward.

Inspection and maintenance work – Overview
(→ Page 40)

11.2 Procuring spare parts

The original components of the product were also certified
as part of the declaration of conformity. If you do not use cer­tified Vaillant original spare parts for maintenance or repair
work, this voids the conformity of the product. We therefore
strongly recommend that you fit Vaillant genuine spare parts.
Information about available Vaillant original spare parts is
available by contacting the contact address provided on the
reverse of this document.

▶ If you require spare parts for maintenance or repair work,

use only Vaillant genuine spare parts.

11.3 Checking the CO₂ content

1. Start up the product with the check programme (P.01)

and set the value.
– Setting value for the programme P.01: 100
Check programmes – Overview (→ Page 30)

2. Wait until the value that is read is stable.

– Waiting period for reading a stable value: 5 min

▶ Set the hot water temperature.

Conditions: Water hardness: > 3.57 mol/m³

– Hot water temperature: ≤ 50 ℃

10 Handing the product over to the

operator

▶ When you have finished the installation, attach the sticker

supplied (in the operator's language) to the product
cover.

▶ Explain to the operator how the safety devices work and

where they are located.

▶ Inform the operator how to handle the product.
▶ In particular, draw attention to the safety information

which the operator must follow.

▶ Inform the operator of the necessity to have the product

maintained on a regular basis.

▶ Instruct the operator about measures taken to ensure the

supply of combustion air and flue gas pipe.

3. Unscrew the cover from the flue gas analysis point (1).

4. Measure the CO₂ content at the flue gas analysis point

(1).

5. Compare the measured value with the corresponding

value in the table.

Checking the CO₂ content

Great Bri­tain

Removed
front cas­ing/installed
front casing

Natural gas

G20

9.2 ±1 %

◁ The value is OK.
▽ The value is not OK; you cannot start up the

product.

▶ Set the CO₂ content. (→ Page 23)

22 Installation and maintenance instructions HOME 0020224355_00

Inspection and maintenance 11

1

B

A

1

C

2

3

4

5

A

B

11.4 Setting the CO₂ content

Conditions: The CO₂ content must be adjusted

▶ Turn the screw (1) to set the CO₂ content (value with

front casing removed).

◁ To increase the CO₂ content: Turn anti-clockwise
◁ To decrease the CO₂ content: Turn clockwise

▶ Only carry out the adjustment in increments of 1/8 turn

and wait approximately 1 minute after each adjustment
until the value has stabilised.

▶ Compare the measured value with the corresponding

value in the table.

Setting the CO₂ value

Great Britain

Removed front cas­ing/installed front
casing

Natural gas

G20

CO₂ at full
load

Set for
Wobbe
index W₀

O₂ at full
load

CO at full
load

CO/CO₂

9.2 ±0.2 %

14.09 kW⋅h/m³

4.5 ±1.8 vol. %

≤ 250 ppm

≤ 0.0027

11.5 Removing the gas-air mixture unit

Note

The gas-air mixture unit consists of three main
components:

– Ventilator

– Gas valve,

– Burner cover

1. Switch off the product via the main switch.

2. Close the gas isolator cock.

3. Push the clip (1) upwards.

4. Remove the flue pipe (2).

▽ If the setting is not in the specified adjustment range,

you must not start up the product.

▶ Inform Customer Service.

▶ Check whether the air-quality requirements with regard

to carbon monoxide are fulfilled.

▶ Install the front casing.

5. Remove the air intake pipe (3).

0020224355_00 HOME Installation and maintenance instructions 23

6. Remove the plugs from the gas valve (4) and from the
fan (5).

11 Inspection and maintenance

A

C

D

B

6

7

7

8

1

1

2

3 4 5

B

A

1

C

2

7. Remove the gas-air mixture unit (6).

8. Remove the burner seals (7) and the burner (8).

9. Check the burner and the heat exchanger for damage
and dirt.

10. If necessary, clean or replace the components accord-

ing to the following sections.

11. Install the two new burner seals.

11.7 Checking the burner

1. Search the surface of the burner for possible damage. If
you see any damage, replace the burner.

2. Install the two new burner seals.

11.8 Checking the ignition electrode

1. Disconnect the connection (2) and the earthing cable
(1).

2. Remove the fixing screws (3).

3. Carefully remove the electrode from the combustion
chamber.

4. Check that the electrode ends (4) are undamaged.

5. Check the electrode distance.
– Clearance for the ignition electrodes: 3.5 … 4.5 mm

6. Make sure that the seal (5) is free from damage.

▽ If necessary, replace the seal.

11.9 Cleaning the condensate tray

1. Switch off the product via the main switch.

2. Close the gas isolator cock.

11.6 Cleaning the heat exchanger

1. Protect the folded down electronics box against sprayed
water.

2. Clean the ribs of the heat exchanger (1) with water.

◁ The water runs out into the condensate tray.

3. Push the clip (1) upwards.

4. Remove the flue pipe (2).

24 Installation and maintenance instructions HOME 0020224355_00

1

5. Using water to clean the condensate tray (1).

C

2

3

1

A

B

1

3

2

3

2

4

◁ The water runs out into the condensate siphon.

11.10 Cleaning the condensate siphon

Inspection and maintenance 11

11.11 Cleaning the filter in the cold water inlet

1. Close the main cold water supply line.

2. Drain the product on the hot water side.

3. Remove the connection piece from the connection for
the product's cold water supply.

4. Clean the filter in the cold water inlet without removing
it.

11.12 Cleaning the heating filter

1. Unclip the lower section of the siphon (1) from the up­per section of the siphon (2).

2. Remove the float (3).

3. Flush out the float and lower section of the siphon with
water.

4. Fill the lower section of the siphon with water up to 10
mm below the upper edge of the condensate drain pipe­work.

5. Reinsert the float (3).

Note

Check whether the float is present in the
condensate siphon.

1. Drain the product. (→ Page 26)

2. Remove the temperature sensor (3).

3. Remove the upper clip (1).

4. Remove the lower clip (2).

5. Remove the supply pipe (3).

6. Remove the heating filter (4) and clean it.

7. Reinstall the components in the reverse order.

6. Clip the lower section of the siphon (1) into the upper
section of the siphon (2).

0020224355_00 HOME Installation and maintenance instructions 25

12 Troubleshooting

11.13 Installing the gas-air mixture unit

1. Install the burner.

2. Install the gas-air mixture unit.

3. Install the air intake pipe.

4. Install the flue pipe.

11.14 Draining the product

1. Close the service valves of the product.

2. Start check programme P.05 (→ Page 16).
Check programmes – Overview (→ Page 30)

3. Open the drain cock.

11.15 Checking the pre-charge pressure of the

expansion vessel

1. Drain the product. (→ Page 26)

2. Measure the pre-charge pressure of the expansion ves­sel at the vessel valve.

Conditions: Pre-charge pressure < 0.075 MPa (0.75 bar)

▶ Top up the expansion vessel in accordance with the

static height of the heating installation, ideally with ni­trogen, otherwise with air. Check that the drain valve is
open when topping up.

3. If water escapes from the valve of the expansion
vessel, you must replace the expansion vessel
(→ Page 28).

4. Fill and purge the heating installation. (→ Page 18)

11.16 Completing inspection and maintenance

work

1. Fill and purge the heating installation. (→ Page 18)

2. Check the gas connection pressure (gas flow pressure).
(→ Page 19)

3. Check the CO₂ content. (→ Page 22)

12.2 Calling up the fault memory

The last ten fault codes are stored in the fault memory.

▶

Hold the button down for more than 7 seconds.
Overview of fault codes (→ Page 35)

▶

Press the button to exit this menu.

12.3 Deleting the fault memory

1. Delete the fault memory using the diagnostics code
d.94.

2. Set the diagnostics code. (→ Page 15)
Overview of diagnostics codes (→ Page 30)

12.4 Resetting parameters to factory settings

1. Reset all parameters to the factory settings using the
diagnostics code d.96.

2. Set the diagnostics code. (→ Page 15)
Overview of diagnostics codes (→ Page 30)

12.5 Preparing the repair work

1. Switch off the product.

2. Disconnect the product from the power mains.

3. Remove the front casing.

4. Close the gas isolator cock.

5. Close the service valves in the heating flow and in the
heating return.

6. Close the service valve in the cold water pipe.

7. Drain the product if you want to replace water-bearing
components of the product.

8. Ensure that water does not drip on live components
(e.g. the electronics box).

9. Use only new seals.

12.6 Replacing defective components

12.6.1 Replacing the burner

12 Troubleshooting

12.1 Rectifying faults

▶ If fault codes (F.XX) are present, refer to the table in the

appendix for advice or use the check programme(s).
Overview of fault codes (→ Page 35)
Check programmes – Overview (→ Page 30)

If several faults occur at the same time, the fault codes are
shown alternately on the display.

▶

Hold the button down for more than 3 seconds.

▶ If you are unable to clear the fault code and it reappears

despite several fault clearance attempts, contact cus­tomer service.

1. Remove the gas-air mixture unit. (→ Page 23)

2. Remove the burner seal.

3. Remove the burner.

4. Install the new burner complete with new seal on the
heat exchanger.

5. Install the gas-air mixture unit. (→ Page 26)

12.6.2 Replacing the gas-air mixture unit

1. Remove the gas-air mixture unit. (→ Page 23)

2. Install the new gas-air mixture unit (→ Page 26).

12.6.3 Replacing the gas valve

1. Disconnect the product from the power mains.

2. Close the gas isolator cock.

26 Installation and maintenance instructions HOME 0020224355_00

B

D

E

A

C

5

6

7

3

2

1

4

3. Remove the air intake pipe (2).

1

A

B

1

2

3

5 4

A

B

2

2 3

B

1

A

1

A

2

3

4

4. Remove the plug from the gas valve (3) and from the
fan (4).

5. Unscrew the gas connection pipe's connection (1) from
the gas valve.

6. Undo the two screws (5).

7. Remove the gas valve (3).

8. Remove the seal (6) if it is still in place on the fan (7).

9. Install the new gas valve in reverse order.

10. Check the CO₂ content. (→ Page 22)

11. Set the CO₂ content. (→ Page 23)

Troubleshooting 12

3. Remove the temperature sensor (3).

4. Remove the upper clip (1).

5. Remove the lower clip (4).

6. Remove the supply pipe (5).

12.6.4 Replacing the heat exchanger

1. Remove the gas-air mixture unit. (→ Page 23)

2. Remove the gas pipe (1).

0020224355_00 HOME Installation and maintenance instructions 27

7. Remove the upper clip (1).

8. Remove the lower clip (3).

9. Remove the return pipe (2).

10. Remove the clip underneath the condensate tray (1).

11. Undo the four screws (2).

12 Troubleshooting

1

3

2

4

A

C

B

D

E

1

2

B

C

1

2

3

A

D

C

C

D

B

A

A

12. Lift the heat exchanger up slightly and remove it to­gether with the condensate tray (1).

13. Undo the four screws (3).

14. Remove the condensate tray.

15. Remove the ignition transformer (2).

16. Use the bolts to secure the condensate tray to the new
heat exchanger.

17. Install the new heat exchanger in reverse order.

12.6.5 Replacing the pump head

2. Undo the nut (3).

3. Remove both screws on the support plate (1).

4. Remove the support plate.

5. Pull out the expansion vessel (2) towards the front.

6. Insert a new expansion vessel into the product.

7. Screw the new expansion vessel onto the water con­nection. To do this, use a new seal.

8. Attach the support plate using both screws.

9. Fill and purge the product and, if necessary, the heating
installation.

12.6.7 Replacing the main PCB

1. Disconnect the pump cable from the electronics box.

2. Undo the four bolts (1).

3. Remove the pump head (2).

4. Replace the O-ring.

5. Use four screws to secure the new pump head.

6. Connect the pump cable to the electronics box.

12.6.6 Replacing the expansion vessel

1. Drain the product. (→ Page 26)

28 Installation and maintenance instructions HOME 0020224355_00

1. Open the electronics box.

2. Pull all of the plugs out from the PCB.

3. Undo the clips on the PCB.

4. Remove the PCB.

5. Install the new PCB in such a way that it clicks into the
groove at the bottom and into the clip at the top.

6. Plug in the PCB plugs.

7. Close the electronics box.

Decommissioning the product 13

B

C

C

D

A

A

1

2

1

B

A

1

2

12.6.8 Replacing the PCB for the user interface

1. Open the electronics box.

2. Pull the plug out of the PCB.

3. Undo the clips on the PCB.

4. Remove the PCB.

5. Install the new PCB in such a way that it clicks into the
groove at the bottom and into the clip at the top.

6. Plug in the PCB plug.

7. Close the electronics box.

12.6.10 Replacing the flow sensor

1. Pull out the plug.

2. Remove the flow sensor (1).

3. Install the new flow sensor.

4. Plug in the plug.

12.6.11 Replace the pressure sensor

12.6.9 Replacing the expansion relief valve

1. Remove the clip (2).

2. Remove the expansion relief valve.

3. Fit the new expansion relief valve with a new O-ring.

4. Reattach the clip (2).

1. Pull out the plug.

2. Remove the clip (1).

3. Remove the pressure sensor (2).

4. Install the new pressure sensor.

5. Reattach the clip (1).

12.7 Completing repair work

▶ Check that the product is running correctly and that it is

completely leak-tight.

13 Decommissioning the product

▶ Decommission the product.
▶ Disconnect the product from the power mains.
▶ Close the gas isolator cock.
▶ Close the cold water stop cock.
▶ Drain the product. (→ Page 26)

14 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.

Vaillant Service Solutions: 0330 100 3461

0020224355_00 HOME Installation and maintenance instructions 29

Appendix

Appendix

A Check programmes – Overview

Note

Since the programme table is used for various products, some programmes may not be visible for the product in
question.

Display Meaning

P.01 Burner operation on adjustable heat input:

The product operates after ignition with the heat input set between "0" (0% = Pmin) and "100" (100% = Pmax).

The function is active for 15 minutes.

P.02 Burner operation at ignition load:

After ignition, the product works at ignition load.

The function is active for 15 minutes.

P.03 The product runs in heating mode with the maximum heat input set using diagnostics code d.00.

P.04 Maximum output function:

If there is a hot water request, the product runs in hot water handling mode and at maximum heat load.

If there is no hot water request, the product runs with the heating partial load that is set via diagnostics code
d.00 and in heating mode.

The function is active for 15 minutes.

P.05 Filling the product:

The diverter valve moves to the mid-position. The burner and pump switch off (to fill or drain the product).

If the pressure is lower than 0.03 MPa (0.3 bar) and then is above 0.05 MPa (0.5 bar) for longer than 15
seconds, the automatic purging function is activated.

The function is active for 15 minutes.

P.06 Purging the heating circuit:

The diverter valve is moved to the heating position.

The function is activated in the heating circuit for 15 minutes.

The pump runs and stops at regular intervals.

If required, this function can be manually switched off.

P.07 Purging the hot water circuit:

The function is activated in the small hot water circuit for 4 minutes and then in the heating circuit for 1 minute.

The pump runs and stops at regular intervals.

If required, this function can be manually switched off.

Automatic air vent
function

Purging the product:

If the pressure is lower than 0.03 MPa (0.3 bar) and then is above 0.05 MPa (0.5 bar) for longer than 15
seconds, the automatic purging function is activated.

The function is activated in the small hot water circuit for 4 minutes and then in the heating circuit for 1 minute.

This function cannot be manually switched off.

B Overview of diagnostics codes

Note

Since the code table is used for various products, some codes may not be visible for the product in question.

Dia­gnostics
code

d.00 Heating maximum output – – kW The maximum heating output

d.01 Pump overrun in heating

Parameter

mode

30 Installation and maintenance instructions HOME 0020224355_00

Values

Unit Increment, select, explanation

Min. Max.

varies depending on the product.
→ Section "Technical data"

Automatic: Unit automatically
adjusts the maximum output to
the current system demand

1 60 min 1 5 Adjustable

Default set­ting

→ Section

"Technical

data"

User-spe­cific setting

Adjustable

Appendix

Dia­gnostics
code

d.02 Maximum burner anti-

d.04 Water temperature in the

d.05 Determined heating flow

d.06 Hot water set target tem-

d.07 Set target temperature

d.08 Status of the 230 V ther-

d.09 Heating flow set target

d.10 Status of the internal

d.11 Status of the heating

d.13 Status of the hot water

d.14 Operating mode of the

d.15 Pump speed Current value % – – Not

d.16 Status of the 24 V room

d.17 Heating control – – – off = Flow temperature

d.18 Pump overrun operating

d.19 Pump operating mode, 2

Parameter

cycling time in heating
mode

cylinder

set target temperature

perature

for the domestic hot wa­ter cylinder

mostat

temperature that is set
on the eBUS room ther­mostat

pump in the heating cir­cuit

circuit's shunt pump

circuit's circulation pump

modulating pump

thermostat

mode

stage pump

Values

Min. Max.

2 60 min 1 20 Adjustable

Current value ℃ – – Not

Current value

Current value ℃ (Combination unit only) – Not

Current value ℃ – – Not

Current value – 0 = Room thermostat open (no

Current value ℃ – – Not

Current value – off / on – Not

Current value – off / on – Not

Current value – off / on – Not

0 5 – 0 = variable rotational speed

Current value – off = Heating off

1 3 – 1 = Comfort (continuously operat-

0 3 – 0 = Burner mode stage 2, pump

Unit Increment, select, explanation

℃ – – Not

heat requirement)

1 = Room thermostat closed
(heat requirement)

(auto)

1; 2; 3; 4; 5 = Fixed rotational
speeds → Section "Setting the
pump output"

on = Heating on

on = Return temperature (ad­justment for underfloor heating.
If you have activated the return
temperature control, the auto­matic heating output determina­tion function is not active.)

ing pump)

3 = Eco (intermittent pump mode
– for the dissipation of the resid­ual heat after hot water gener­ation at an extremely low heat
demand)

flow/overrun stage 1

1 = Heating mode and pump
flow/overrun stage 1, hot water
handling mode stage 2

2 = Automatic heating mode,
pump flow/overrun stage 1, hot
water handling mode stage 2

3 = Stage 2

Default set­ting

– Not

0 Adjustable

– Not

0 Adjustable

1 Adjustable

3 Adjustable

User-spe­cific setting

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

0020224355_00 HOME Installation and maintenance instructions 31

Appendix

Dia­gnostics
code

d.20 Maximum hot water set

d.21 Status of the warm start

d.22 Status of the hot water

d.23 Status of the heating

d.24 Status of the pressure

d.25 Status of the requirement

d.27 Function of relay 1

d.28 Function of relay 2

d.31 Automatic filling device 0 2 – 0 = Manual

d.33 Fan speed target value Current value rpm Fan speed = Display value x 100 – Not

d.34 Value for the fan speed Current value rpm Fan speed = Display value x 100 – Not

d.35 Position of the diverter

d.36 Value for the hot water

d.39 Water temperature in the

d.40 Heating flow temperature Current value ℃ – – Not

d.41 Heating return temperat-

d.43 Heating curve 0.2 4 – 0.1 1.2 Adjustable

Parameter

target temperature

for hot water

request

demand

monitor

to reheat the cylinder or
for the hot water warm
start from the eBUS ther­mostat

(multi-functional module)

(multi-functional module)

valve

flow

solar circuit

ure

Values

Unit Increment, select, explanation

Min. Max.

50 60 ℃ 1 50 Adjustable

Current value – off = Function deactivated

on = Function activated and
available

Current value – off = No current requirement

on = Current requirement

Current value – off = Heating off (Summer mode)

on = Heating on

0 1 – off = Not switched

on = Switched

Current value – off = Function deactivated

on = Function activated

1 10 – 1 = Circulation pump

2 = External pump

3 = Cylinder charging pump

4 = Extractor hood

5 = External solenoid valve

6 = External fault message

7 = Solar pump (omitted)

8 = eBUS remote control

9 = Legionella protection pump

10 = Solar valve

1 10 – 1 = Circulation pump

2 = External pump

3 = Cylinder charging pump

4 = Extractor hood

5 = External solenoid valve

6 = External fault message

7 = Solar pump (omitted)

8 = eBUS remote control

9 = Legionella protection pump

10 = Solar valve

1 = Semi-automatic

2 = Automatic

Current value – 0 = Heating

40 = Mid-position (parallel opera­tion)

100 = Domestic hot water

Current value l/min – – Not

Current value ℃ – – Not

Current value ℃ – – Not

Default set­ting

– Not

– Not

– Not

– Not

– Not

1 Adjustable

2 Adjustable

0 Adjustable

– Not

User-spe­cific setting

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

32 Installation and maintenance instructions HOME 0020224355_00

Appendix

Dia­gnostics
code

d.45 Value for the base point

d.47 Outside temperature Current value ℃ – – Not

d.50 Correction of the min-

d.51 Correction of the max-

d.58 Solar circuit reheating 0 3 – 0 = Boiler's Legionella protection

d.60 Number of blocks by the

d.61 Number of unsuccessful

d.62 Night set-back 0 30 – 1 0 Adjustable

d.64 Average burner ignition

d.65 Maximum burner ignition

d.66 Activation of the warm

d.67 Remaining burner anti-

d.68 Number of unsuccessful

d.69 Number of unsuccessful

d.70 Operation of the diverter

d.71 Maximum heating flow

d.73 Correction of the hot wa-

d.75 Maximum cylinder re-

d.77 Max. cylinder reheating – – kW 1

d.80 Running time in heating

d.81 Running time in hot wa-

d.82 Number of burner igni-

d.83 Number of burner igni-

Parameter

of the heating curve

imum fan speed

imum fan speed

temperature limiter

ignitions

time

time

start function for hot wa­ter

cycling time (setting un­der d.02)

ignitions at 1st attempt

ignitions at 2nd attempt

valve

set target temperature

ter warm start temperat­ure

heating time

mode

ter handling mode

tions in heating mode

tions in hot water hand­ling mode

Values

Unit Increment, select, explanation

Min. Max.

15 30 – 1 20 Adjustable

0 3000 rpm 1

Fan speed = Display value x 10

-2500 0 rpm 1

Fan speed = Display value x 10

function deactivated

3 = Hot water activated (min.
target value 60 °C)

Current value – – – Not

Current value – – – Not

Current value s – – Not

Current value s – – Not

– – – off = Function deactivated

on = Function activated

Current value min – – Not

Current value – – – Not

Current value – – – Not

0 2 – 0 = Normal operating mode

(DHW and heating mode)

1 = Mid-position (parallel opera­tion)

2 = Permanent setting: Heating
mode

45 80 ℃ 1 → Section

-15 5 K 1 0 Adjustable

20 90 min 1 45 Adjustable

→ Section "Technical data"

Current value h Running time = Display value x

100

Current value h Running time = Display value x

100

Current value – Number of ignitions = Display

value x 100

Current value – Number of ignitions = Display

value x 100

Default set­ting

600 Adjustable

-1000 Adjustable

0 Adjustable

1 Adjustable

0 Adjustable

"Technical

data"

– Adjustable

– Not

– Not

– Not

– Not

User-spe­cific setting

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

adjustable

Adjustable

adjustable

adjustable

adjustable

adjustable

0020224355_00 HOME Installation and maintenance instructions 33

Appendix

Dia­gnostics
code

d.84 Maintenance in 0 3000 h Number of hours = Display value

d.85 Increase in the min. out-

d.88 Flow rate limit value

d.90 Status of the eBUS room

d.91 Status DCF77 Current value – – – Not

d.93 Setting the product code 0 99 – 1 – Adjustable

d.94 Delete fault list 0 1 – off = No

d.95 Software versions – – – 1 = Main PCB

d.96 Default setting (reset) – – – 0 = No

d.128 Heating minimum target

d.129 Minimum hot water tar-

Parameter

put (heating and hot wa­ter handling mode)

for ignition in hot water
handling mode

thermostat

value

get value

Values

Min. Max.

– – kW 1

0 1 – 0 = 1.7 l/min (no delay)

Current value – off = Not connected

10 75 ℃ 1 10 Adjustable

35

(com-

bination

unit)

45

(pure

boiler)

60 ℃ 1 35

Unit Increment, select, explanation

x 10

→ Section "Technical data"

1 = 3.7 l/min (2 s delay)

on = Connected

on = Yes

2 = Interface PCB

1 = Yes

Default set­ting

300 Not

– Adjustable

0 Adjustable

– Not

– Adjustable

– Adjustable

– Adjustable

(combination

unit)

45 (pure

boiler)

User-spe­cific setting

adjustable

adjustable

adjustable

Adjustable

C Status codes – Overview

Note

Since the code table is used for various products, some codes may not be visible for the product in question.

Status code Meaning

Displays in heating mode

S.0 Heating mode: No requirement

S.01 Heating mode: Advance fan operation

S.02 Heating mode: Pump pre-run

S.03 Heating mode: Burner ignition

S.04 Heating mode: Burner on

S.05 Heating mode: Pump/fan overrun

S.06 Heating mode: Fan overrun

S.07 Heating mode: Pump overrun

S.08 Heating mode: Temporary shutdown after heating procedure

Displays in hot water handling mode

S.10 Hot water handling mode: Requirement

S.11 Hot water handling mode: Advance fan operation

S.13 Hot water handling mode: Burner ignition

S.14 DHW mode: Burner on

S.15 DHW mode: Pump/fan overrun

S.16 DHW mode: Fan overrun

34 Installation and maintenance instructions HOME 0020224355_00

Appendix

Status code Meaning

S.17 DHW mode: Pump overrun

Display in Comfort mode with warm start or hot water handling mode with cylinder

S.20 Hot water handling mode: Requirement

S.21 Hot water handling mode: Advance fan operation

S.22 Hot water handling mode: Pump pre-run

S.23 Hot water handling mode: Burner ignition

S.24 DHW mode: Burner on

S.25 DHW mode: Pump/fan overrun

S.26 DHW mode: Fan overrun

S.27 DHW mode: Pump overrun

S.28 Hot water handling mode: Temporary shutdown of the burner

Other displays

S.30 Room thermostat is blocking heating mode.

S.31 No heating demand: Summer mode, eBUS controller, waiting period

S.32 Fan waiting time: Fan speed outside of the tolerance values

S.33 Forced fan operation until the pressure monitor is switched

S.34 Frost protection active

S.39 Underfloor heating contact open

S.41 Water pressure too high

S.42 Flue non-return flap closed

S.46 Protection mode: Minimum load

S.53 Product in waiting period/operation block function due to low water pressure (flow/return spread too large)

S.54 Waiting period: Low water pressure in the circuit (flow/return spread too large)

S.88 Product purging active

S.91 Maintenance: Demo mode

S.96 Automatic test programme: Return temperature sensor, heating and hot water request blocked.

S.97 Automatic test programme: Water pressure sensor, heating and hot water request blocked.

S.98 Automatic test programme: Return temperature sensor, heating and hot water request blocked.

S.99 Automatic filling active

S.108 Purging the combustion chamber, fan in operation

S.109 Product's standby mode activated

D Overview of fault codes

Note

Since the code table is used for various products, some codes may not be visible for the product in question.

Fault code Meaning Possible cause

F.00 Fault: Flow temperature sensor NTC plug not plugged in or has come loose, multiple plug on the PCB not

plugged in correctly, interruption in cable harness, NTC sensor defective

F.01 Fault: Return temperature sensor NTC plug not plugged in or has come loose, multiple plug on the PCB not

plugged in correctly, interruption in cable harness, NTC sensor defective

F.10 Short circuit: Flow temperature sensor NTC sensor defective, short circuit in the cable harness, cable/casing

F.11 Short circuit: Return temperature sensor NTC sensor defective, short circuit in the cable harness, cable/casing

F.13 Short circuit: Domestic hot water cylinder

temperature sensor

F.20 Safety switch-off: Overheating temperat-

ure reached

0020224355_00 HOME Installation and maintenance instructions 35

NTC sensor defective, short circuit in the cable harness, cable/casing

Incorrect earth connection between cable harness and product, flow or return
NTC defective (loose connection), black discharge via ignition cable, ignition
plug or ignition electrode

Appendix

Fault code Meaning Possible cause

F.22 Safety switch-off: Low water pressure in

the boiler

F.23 Safety switch-off: Temperature difference

too great (NTC1/NTC2)

F.24 Safety switch-off: Temperature rise too

fast

F.25 Safety switch-off: Flue gas temperature

too high

F.27 Safety switch-off: Fault in flame detection Moisture on the electronics, electronics (flame monitor) defective, gas solen-

F.28 Fault: Ignition unsuccessful when startingupGas meter defective or gas pressure monitor has triggered, air in gas, gas

F.29 Fault: Flame loss Gas supply temporarily stopped, flue gas recirculation, incorrect earthing of

F.32 Fan frost protection function active: Fan

speed outside the tolerance values

F.33 Fan frost protection function active: Air

pressure switch fault

F.49 eBUS fault: Voltage too low Short circuit on eBUS, eBUS overload or two power supplies with different

F.61 Fault: Gas valve control system Short circuit/short to earth in cable harness for the gas valve, gas valve

F.62 Fault: Gas valve switch-off control Delayed switch-off of gas valve, delayed extinguishing of flame signal, gas

F.63 Fault: EEPROM Electronics defective

F.64 Fault: Electronics/sensor/analogue-to-

digital converter

F.65 Fault: Electronics temperature too high Electronics overheating due to external influences, electronics defective

F.67 Value sent back by ASIC is incorrect

(flame signal)

F.68 Fault: Unstable flame (analogue input) Air in gas, gas flow pressure too low, incorrect air ratio, incorrect gas re-

F.70 Invalid product code (DSN) Replace the screen and PCB at the same time without reconfiguring the

F.71 Fault: Flow/return temperature sensor Flow temperature sensor specifies a constant value: Flow temperature

F.72 Fault: Deviation in the water pressure

sensor/return temperature sensor

F.73 Fault: Water pressure sensor not con-

nected or has short-circuited

F.74 Fault: Electrical problem in the water

pressure sensor

F.75 Fault: Pressure sensor Pressure sensor or pump defective or low water pressure

F.77 Fault: Condensate or smoke No response, flue non-return flap defective

F.78 Interruption to DHW outlet sensor at

external controller

No or insufficient water in the product, water pressure sensor de­fective, cable to the pump or to the water pressure sensor loose/not
connected/defective

Pump blocked, insufficient pump output, air in product, flow and return NTC
sensors connected the wrong way round

Pump blocked, reduced pump output, air in product, system pressure too
low, return flow prevention blocked/incorrectly installed

Break in connection for optional flue gas safety temperature limiter (safety
cut-out), break in cable harness

oid valve leaking

flow pressure too low, thermal isolator device (TAE) has triggered, incorrect
gas restrictor, incorrect spare gas valve, fault on the gas valve, multiple plug
on PCB incorrectly plugged in, break in cable harness, ignition system (ig­nition transformer, ignition cable, ignition plug, ignition electrode) defective,
ionisation current interrupted (cable, electrode), incorrect earthing of product,
electronics defective

product, ignition transformer has spark failure

Plug on fan not correctly plugged in, multiple plug on PCB not correctly
plugged in, break in cable harness, fan blocked, Hall sensor defective, elec­tronics defective

Pressure monitor has not switched or has switched at a fan speed value that
is too high (insufficient air supply)

Pressure monitor plug not correctly plugged in, pressure monitor defective,
line removed from between the pressure monitor and silencer, air/flue pipe
blocked and silencer not installed properly

polarities on the eBUS

defective (coils shorted to earth), electronics defective

valve leaking, electronics defective

Flow or return NTC short circuited, electronics defective

Implausible flame signal, electronics defective

strictor, ionisation flow interruption (cable, electrode)

product's Device Specific Number

sensor incorrectly attached to the flow pipe, flow temperature sensor de­fective

Flow/return NTC sensor temperature difference too great → flow and/or
return temperature sensor defective

Interruption/short circuit of water pressure sensor, interruption/short to earth
in supply line to water pressure sensor or water pressure sensor defective

Line to water pressure sensor has a short circuit to 5 V/24 V or internal fault
in the water pressure sensor

Link box connected, but hot water NTC not bridged

36 Installation and maintenance instructions HOME 0020224355_00

Appendix

Fault code Meaning Possible cause

F.83 Fault: Burner temperature sensor Burner temperature sensor is defective

When the burner starts, the temperature change recorded by the flow or
return temperature sensor is non-existent or too small: Insufficient water in
the product, flow or return temperature sensor incorrectly attached to the
pipe

F.84 Fault: Flow/return temperature sensor Values not consistent, difference < -6 K

Flow and return temperature sensors signalling implausible values: Flow and
return temperature sensors have been inverted, flow and return temperature
sensors have not been correctly installed

F.85 Fault: Temperature sensor The flow and/or return temperature sensors have been installed on the same

pipe/incorrect pipe

Temperature sensor not connected or is connected incorrectly

F.86 Fault: Underfloor heating contact Underfloor heating contact open, sensor disconnected or defective

F.87 Fault: Ignition electrode Ignition electrode not connected or not connected properly, short circuit in

the cable harness

F.88 Fault: Gas valve Gas valve not connected or it is connected incorrectly, short circuit in the

cable harness

F.89 Fault: Pump Pump not connected or it is connected incorrectly, incorrect pump connec-

ted, short circuit in the cable harness

0020224355_00 HOME Installation and maintenance instructions 37

Appendix

X2

X14

L

N

19

10

20

2

6

3

11

13

14

18

7

17

8

X51

X51

X20

16

1
9

3

15

4

5

10

11

6

13

X51 X35

X20

X40 X51

X30

X2

X21

X41

X22

X14

L

N

–

+

24V=

RT BUS

Burner

off

RT

230Vac

X1

FUS

X106

X32

X90

X12

X35

X1

X21

L

N

RT 230Vac

L

N

X35

1

3

4

1

3

3

1

2

M

1

3

4

6

1

2

3

eBUS

Burner off

X106

M

5

4

2

1

2

1

2

1

N

L

L

24V

230V~

24V

230V~

2

8

9

10

11

1312

1

5

4

3

6

7

15

14

E Connection diagram: Combination unit

9 3-way valve

10 Pressure sensor

11 Volume flow sensor

12 Ionisation electrode

13 Heating pump

14 Ignition electrode

15 Main power supply

1 Main PCB

2 Interface PCB

3 Timer

4 Control system

5 Temperature sensor in the heating flow

6 Temperature sensor in the heating return

7 Fan

8 Gas valve

38 Installation and maintenance instructions HOME 0020224355_00

F Connection diagram: Combination unit (35 kW)

X20

X40 X51

X30

X2

X21

X41

X22

X14

L

N

–

+

24V=

RT BUS

Burner

off

RT

230Vac

X1

FUS

X106

X32

X90

X12

X35

X2

X14

L

N

19

10

20

2

6

3

11

13

14

18

7

17

8

X12

L

N

X51

X51

X20

16

1
9

3

15

4

5

10

11

6

13

X51

X1

X21

L

N

L

N

1

3

4

1

3

3

1

2

M

1

3

4

6

1

2

3

eBUS

Burner off

X106

M

4

3

2

1

5

4

2

1

5

6

7

8

2

1

2

1

N

L

X35

X35

24V

230V~

24V

230V~

2

8

9

10

11

13

12

1

5

4

6

7

15

14

3

Appendix

1 Main PCB

2 Interface PCB

3 Timer

4 Control system

5 Temperature sensor in the heating flow

6 Temperature sensor in the heating return

7 Fan

8 Gas valve

9 3-way valve

10 Pressure sensor

11 Volume flow sensor

12 Ionisation electrode

13 Heating pump

14 Ignition electrode

15 Main power supply

0020224355_00 HOME Installation and maintenance instructions 39

Appendix

G Inspection and maintenance work – Overview

The table below lists the manufacturer requirements with respect to minimum inspection and maintenance intervals. If na­tional regulations and directives require shorter inspection and maintenance intervals, you should observe these instead of
the intervals listed in the table.

Maintenance

No. Work

Check the air/flue pipe for leak-tightness and to ensure that it is fastened correctly. Make sure

1

that it is not blocked or damaged and has been installed in accordance with the relevant In­stallation Manual.

Check the general condition of the product. Remove any dirt from the product and the vacuum

2

chamber.

Visually inspect the general condition of the heat exchanger. In doing so, pay particular atten-

3

tion to signs of corrosion, rust and other defects. If you notice any damage, carry out mainten­ance work.

Check the gas connection pressure at maximum heat input. If the gas connection pressure is

4

not within the specified range, carry out maintenance work.

Check the CO₂ content (air ratio) of the product and, if necessary, adjust it.

5

Disconnect the product from the power mains. Check that the plug connections and electrical

6

connections are correct and make any necessary adjustments.

Close the gas isolator cock and the service valves.

7

Drain the product on the water side. Check the pre-charge pressure of the expansion vessel,

8

and top up the vessel if necessary (approx. 0.03 MPa/0.3 bar under the system filling pres­sure).

9 Check the ignition electrode. X X

Remove the gas-air mixture unit.

10

Replace both burner seals each time it is opened and accordingly each time maintenance

11

work is carried out.

Clean the heat exchanger.

12

→ Section "Cleaning the heat exchanger"

Check the burner for damage and replace it if necessary.

13

Check the condensate siphon in the product, clean it and, if required, replace it.

14

→ Section "Cleaning the condensate siphon"

Install the gas-air mixture unit. Caution: Replace the seals.

15

If necessary, if the hot water output is insufficient or the outlet temperature is not reached,

16

replace the plate heat exchanger.

Clean the filter in the cold water inlet. Replace the filter if impurities can no longer be removed

17

or if the filter is damaged. If this is the case, also check that the impeller sensor is not dirty or
damaged. Clean the sensor (do not use compressed air) and, if it is damaged, replace it.

Open the gas isolator cock, reconnect the product to the mains and switch it on.

18

If the automatic purging programme does not start, open the service valves, fill the product

19

or the heating installation to 0.1-0.2 MPa/1.0-2.0 bar (depending on the static height of the
heating installation) and manually start the purging programme P.07.

Perform a test operation of the product and heating installation, including hot water generation

20

(if available), and purge the system once more if necessary.

21 Check the CO₂ content (the air ratio) of the product again.

Ensure that no gas, flue gas, water or condensate is leaking from the product. Restore leak-

22

tightness if necessary.

Record the inspection/maintenance work carried out.

23

*Note: For those appliances which are not part of an annual service agreement/policy, maintenance must be carried out at least every
5 years.

Inspection

(annual)

X X

X X

X X

X X

X X

X X

X X

X X

X X

X X

X X

(must be

carried out at

regular

intervals)*

X

X

X

X

X

X

X

X

X

X

X

40 Installation and maintenance instructions HOME 0020224355_00

H Opening in the air/flue pipe

G

N

N

MM

A

I

I

O

H

H

C

B

L

J

Q

Q

Q

Q

Q

K

P

D, E

F

I

S

R

T

Appendix

H.1 Positioning of the opening of a fan-supported flue gas pipe

Installation site

A

B Above an opening, air bricks, opening windows, etc., that can be opened. 300 mm

C Horizontally to an opening, air bricks, opening windows, etc., that can be opened. 300 mm

D

E Below eaves 200 mm

F Below balconies or car port roofs 200 mm

G From vertical wastewater pipes or down pipes 150 mm

H From external or internal corners 200 mm

I Above floors, roofs or balconies 300 mm

J From a surface facing a terminal 600 mm

K From a terminal facing a terminal 1,200 mm

L From an opening in the car port (e.g. door, window) which leads into the dwelling 1,200 mm

M Vertical from a terminal on the same wall 1,500 mm

N Horizontal from a terminal on the same wall 300 mm

O From the wall on which the terminal has been installed 0 mm

P From a vertical structure on the roof N/A

Q Above the roof area 300 mm

R Horizontal from adjacent windows on pitched or flat roofs 600 mm

S Above adjacent windows on pitched or flat roofs 600 mm

T Below adjacent windows on pitched or flat roofs 2,000 mm

Directly below an opening, air bricks, opening windows, etc., that can be opened. 300 mm

Below temperature-sensitive building components, e.g. plastic gutters, down pipes or wastewater
pipes

Minimum dimen­sions

75 mm

0020224355_00 HOME Installation and maintenance instructions 41

Appendix

Balcony/eaves

Gutter

Adequately secured
air/flue gas pipe

The flue pipe must
protrude beyond any overhang

H.2 Text from BS 5440-1 on fan-supported flue gas pipes

BS 5440–1: It is recommended that the fanned flue gas system terminal is positioned as follows:

– At least 2 m from an opening in the building directly opposite, and
– So that the combustion products are not discharged directly across a property boundary.
– Dimensions D, E, F and G: These clearances may be reduced to 25 mm without affecting the performance of the boiler.

In order to ensure that the condensate vapour plume does not damage adjacent surfaces, the terminal should be exten­ded as shown.

– Dimension H: This clearance may be reduced to 25 mm without adversely affecting the performance of the boiler. How-

ever, in order to ensure that the condensate vapour plume does not damage adjacent surfaces, a clearance of 300 mm is
preferred. For IE, recommendations are given in the current issue of the IS 813.

H.3 Opening of the flue pipe below eaves and balconies

42 Installation and maintenance instructions HOME 0020224355_00

I Commissioning Checklist

© Heating and Hotwater Industry Council (HHIC)

www.centralheating.co.uk

Benchmark Commissioning and
Servicing Section

It is a requirement that the boiler is installed and commissioned to the

completed in full.

Appendix

0020224355_00 HOME Installation and maintenance instructions 43

Appendix

This Commissioning Checklist is to be completed in full by the competent person who commissioned the boiler as a means of demonstrating
compliance with the appropriate Building Regulations and then handed to the customer to keep for future reference.

GAS BOILER SYSTEM COMMISSIONING CHECKLIST

CONTROLS

Optimum start control

Fitted

Fitted

Fitted

Fitted

ALL SYSTEMS

Yes

Yes

CENTRAL HEATING MODE

OR

mbar OR mbar

COMBINATION BOILERS ONLY

Yes

Yes

DOMESTIC HOT WATER MODE

OR

mbar OR mbar

Yes Temperature

CONDENSING BOILERS ONLY

Yes

ALL INSTALLATIONS

AND

²

Ratio

AND

²

Ratio

Yes

Yes

Yes

Yes

44 Installation and maintenance instructions HOME 0020224355_00

It is recommended that your heating system is serviced regularly and that the appropriate Service Interval Record is completed.

Service Provider

SERVICE RECORD

SERVICE 01

AND

²

%

AND

²

%

SERVICE 02

AND

²

%

AND

²

%

SERVICE 03

AND

²

%

AND

²

%

SERVICE 04

AND

²

%

AND

²

%

SERVICE 05

AND

²

%

AND

²

%

SERVICE 06

AND

²

%

AND

²

%

SERVICE 07

AND

²

%

AND

²

%

SERVICE 08

AND

²

%

AND

²

%

SERVICE 09

AND

²

%

AND

²

%

SERVICE 10

AND

²

%

AND

²

%

Appendix

0020224355_00 HOME Installation and maintenance instructions 45

Appendix

PRIOR TO CO AND COMBUSTION RATIO CHECK

The boiler manufacturer’s installation instructions should have been followed, gas type verified and gas

supply pressure/rate checked as required prior to commissioning.

As part of the installation process, especially where a flue has been fitted by persons other than the

boiler installer, visually check the integrity of the whole flue system to confirm that all components are

correctly assembled, fixed and supported. Check that manufacturer’s max. flue lengths have not been

exceeded and all guidance has been followed (e.g. Gas Safe Technical Bulletin TB008).

The flue gas analyser should be of the correct type, as specified by BS 7967

Prior to its use, the flue gas analyser should have been maintained and calibrated as specified by the

manufacturer. The installer must have the relevant competence for use of the analyser.

Check and zero the analyser IN FRESH AIR as per analyser manufacturer’s instructions.

NOTE

THE AIR GAS RATIO VALVE IS FACTORY

SET AND MUST NOT BE ADJUSTED

DURING COMMISSIONING UNLESS THIS

ACTION IS RECOMMENDED FOLLOWING

CONTACT WITH THE MANUFACTURER.

If any such adjustment is recommended and

further checking of the boiler is required the

installer/service engineer must be competent

to carry out this work and to use the flue gas

analyser accordingly.

If the boiler requires conversion to operate with

a different gas family (e.g. conversion from

natural gas to LPG) separate guidance will be

provided by the boiler manufacturer

CARRY OUT FLUE INTEGRITY CHECK USING ANALYSER

Insert analyser probe into air inlet test point and allow readings to stabilise.

NOTE - where no air inlet test point is provided then a flue integrity check

with the analyser is not possible. The installer should verify that flue

integrity has been visually checked in accordance with the “Prior to CO

and combustion ratio check” box above before proceeding to the

“Check CO and combustion ratio at maximum rate” stage below.

SET BOILER TO MINIMUM RATE

In accordance with boiler instructions, set boiler to operate at minimum rate (to

minimum load condition). Allow sufficient time for combustion to stabilise.

NOTE - If manufacturer’s instructions do not specify how to set boiler to minimum

rate contact Technical Helpline for advice.

CHECK CO AND COMBUSTION RATIO AT MINIMUM RATE

With boiler still set at minimum rate, insert analyser probe into flue gas sampling

point. Allow readings to stabilise before recording.

NOTE - If no flue gas sampling point is present and the correct procedure is not

specified in the manual, consult boiler manufacturer for guidance.

CHECK CO AND COMBUSTION RATIO AT MAX. RATE

With boiler still set at maximum rate, insert analyser probe into flue gas

sampling point. Allow readings to stabilise before recording.

NOTE - If no flue gas sampling point is present and the correct procedure is

not specified in the manual, consult boiler manufacturer for guidance.

SET BOILER TO MAXIMUM RATE

In accordance with boiler instructions, set boiler to operate at max. rate

(full load condition). Allow sufficient time for combustion to stabilise.

NOTE - Do not insert analyser probe during this period to avoid

possible “flooding” of sensor.

Is

CO less than

350ppm and

CO/CO

2

ratio

less than 0.004

Is

O2 ≥ 20.6%

and

CO2 < 0.2%

Is

CO less than

350ppm and

CO/CO

2

ratio

less than 0.004

BOILER IS OPERATING SATISFACTORILY

no further actions required.

Ensure test points are capped, boiler case is correctly replaced and

all other commissioning procedures are completed.

Complete Benchmark Checklist, recording CO and combustion ratio

readings as required.

TURN OFF APPLIANCE AND CALL

MANUFACTURER’S TECHNICAL HELPLINE

FOR ADVICE.

THE APPLIANCE MUST NOT BE

COMMISSIONED UNTIL PROBLEMS ARE

IDENTIFIED AND RESOLVED.

VERIFY FLUE INTEGRITY

Analyser readings indicate that combustion products

and inlet air must be mixing. Further investigation of

the flue is therefore required.

Check that flue components are assembled, fixed

and supported as per boiler/flue manufacturer’s

instructions.

Check that flue and flue terminal are not obstructed.

Is

CO less than

335ppm

and

CO/CO2 ratio less

than 0.004

Is

O2 ≥ 20.6%

and

CO

2

< 0.2%

Check all seals around the appliance burner,

internal flue seals, door and case seals.

Rectify where necessary.

TURN OFF APPLIANCE AND CALL

MANUFACTURER’S TECHNICAL HELPLINE

FOR ADVICE.

THE APPLIANCE MUST NOT BE

COMMISSIONED UNTIL PROBLEMS ARE

IDENTIFIED AND RESOLVED. IF

COMMISSIONING CANNOT BE FULLY

COMPLETED, THE APPLIANCE MUST BE

DISCONNECTED FROM THE GAS SUPPLY IN

ACCORDANCE WITH THE GSIUR.

NOTE: Check and record CO and combustion ratio

at both max. and min. rate before contacting the

manufacturer.

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

J Combustion chart

46 Installation and maintenance instructions HOME 0020224355_00

K Lengths of the air/flue pipe

Length of the C13 type flue pipe

HOME COMBI 25 -A (H-GB)
Length

of
HOME COMBI 30 -A (H-GB)
the

air/flue
HOME COMBI 35 -A (H-GB)

pipe

Length of the C33 type flue pipe

HOME COMBI 25 -A (H-GB)
Length

of
HOME COMBI 30 -A (H-GB)
the

air/flue
HOME COMBI 35 -A (H-GB)

pipe

Length of the C43 type flue pipe

HOME COMBI 25 -A (H-GB)
Length

of
HOME COMBI 30 -A (H-GB)
the

air/flue
HOME COMBI 35 -A (H-GB)

pipe

Appendix

C13 type flue pipe

Dia. 60/100 (L) Dia. 80/125 (L)

≤ 10 m ≤ 25 m

≤ 10 m ≤ 25 m

≤ 6 m ≤ 19 m

C33 type flue pipe

Dia. 60/100 (L) Dia. 80/125 (L)

≤ 10 m ≤ 25 m

≤ 10 m ≤ 25 m

≤ 10 m ≤ 19 m

C43 type flue pipe

Dia. 60/100 (L)

≤ 10 m

≤ 10 m

≤ 10 m

L Technical data

Technical data – Heating

HOME COMBI
25 -A (H-GB)

Maximum heating flow temperat­ure (default setting)

Max. range of the flow temperat­ure regulation

Maximum permissible pressure

Nominal water flow (ΔT = 20 K)

Nominal water flow (ΔT = 30 K)

Approximate value for the
condensate volume (pH value
between 3.5 and 4.0) at 50/30 °C

ΔP heating at nominal flow (ΔT =
20 K) – (bypass default setting)

ΔP heating at nominal flow (ΔT =
20 K) – (bypass closed)

Technical data – G20 power/loading G20

Maximum heat output (default set­ting – d.00)

Effective output range (P) at
50/30 °C

75 ℃ 75 ℃ 75 ℃

10 … 80 ℃ 10 … 80 ℃ 10 … 80 ℃

0.3 MPa

(3.0 bar)

655 l/h 655 l/h 655 l/h

436 l/h 436 l/h 436 l/h

1.53 l/h 1.53 l/h 1.53 l/h

0.025 MPa

(0.250 bar)

0.041 MPa

(0.410 bar)

HOME COMBI
25 -A (H-GB)

Automatic Automatic Automatic

5.3 … 15.9 kW 6.3 … 15.9 kW 7.4 … 15.9 kW

HOME COMBI
30 -A (H-GB)

0.3 MPa

(3.0 bar)

0.025 MPa

(0.250 bar)

0.039 MPa

(0.390 bar)

HOME COMBI
30 -A (H-GB)

HOME COMBI
35 -A (H-GB)

0.3 MPa

(3.0 bar)

0.025 MPa

(0.250 bar)

0.042 MPa

(0.420 bar)

HOME COMBI
35 -A (H-GB)

0020224355_00 HOME Installation and maintenance instructions 47

Appendix

HOME COMBI
25 -A (H-GB)

Effective output range (P) at
80/60 °C

Hot water heat output range (P)

Maximum heat input – heating (Q
max.)

Minimum heat input – heating (Q
min.)

Maximum heat input – hot water
(Q max.)

Minimum heat input – hot water (Q
min.)

5.1 … 15.2 kW 6.1 … 15.2 kW 7.1 … 15.2 kW

5 … 25.2 kW 6 … 30 kW 7 … 35 kW

15.3 kW 15.3 kW 15.3 kW

5.1 kW 6.1 kW 7.1 kW

25.7 kW 30.6 kW 35.7 kW

5.1 kW 6.1 kW 7.1 kW

Technical data – Domestic hot water

HOME COMBI
25 -A (H-GB)

Specific flow rate (D) (ΔT = 30 K)
in accordance with EN 13203

Continuous flow rate (ΔT = 35 K)

Specific flow rate (ΔT = 35 K)

Minimum permissible pressure

Maximum permissible pressure

Temperature range

Throughflow volume limiter

12.1 l/min 14.5 l/min 16.8 l/min

622 l/h 746 l/h 864 l/h

10.4 l/min 12.4 l/min 14.4 l/min

0.03 MPa

(0.30 bar)

1 MPa

(10 bar)

35 … 60 ℃ 35 … 60 ℃ 35 … 60 ℃

10 l/min 12 l/min 14 l/min

HOME COMBI
30 -A (H-GB)

HOME COMBI
30 -A (H-GB)

0.03 MPa

(0.30 bar)

1 MPa

(10 bar)

HOME COMBI
35 -A (H-GB)

HOME COMBI
35 -A (H-GB)

0.03 MPa

(0.30 bar)

1 MPa

(10 bar)

Technical data – General

Diameter of the gas pipe

Diameter of the heating pipe

Expansion relief valve connector
(min.)

Condensed water discharge pipe
(min.)

G20 gas supply pressure

Gas flow at P max. – hot water
(G20)

CE number (PIN)

Smoke mass flow in heating mode
at P min.

Smoke mass flow in heating mode
at P max.

Smoke mass flow in hot water
handling mode at P max.

Released system types

Nominal efficiency at 80/60 °C

Nominal efficiency at 50/30 °C

Nominal efficiency in partial load
operation (30%) at 40/30 °C

NOx class

Product dimensions, width

Product dimensions, depth

Product dimensions, height

HOME COMBI
25 -A (H-GB)

1/2 inch 1/2 inch 1/2 inch

3/4 inch 3/4 inch 3/4 inch

15 mm 15 mm 15 mm

21.5 mm 21.5 mm 21.5 mm

20 mbar 20 mbar 20 mbar

2.7 m³/h 3.2 m³/h 3.8 m³/h

CE-0063CP3646 CE-0063CP3646 CE-0063CP3646

2.34 g/s 2.80 g/s 3.26 g/s

6.9 g/s 6.9 g/s 6.9 g/s

11.6 g/s 13.8 g/s 16.1 g/s

C13, C33, C43,
C53

99.5 % 99.5 % 99.5 %

104 % 104 % 104 %

108.5 % 108.5 % 108.5 %

5 5 5

418 mm 418 mm 418 mm

300 mm 300 mm 300 mm

740 mm 740 mm 740 mm

HOME COMBI
30 -A (H-GB)

C13, C33, C43,
C53

HOME COMBI
35 -A (H-GB)

C13, C33, C43,
C53

48 Installation and maintenance instructions HOME 0020224355_00

Appendix

Net weight

Weight when filled with water

Technical data – Electrics

Electric connection

Built-in fuse (slow-blow)

Max. electrical power consump­tion

Standby electrical power con­sumption

Level of protection

HOME COMBI
25 -A (H-GB)

32 kg 32.6 kg 32.7 kg

36 kg 37.1 kg 37.2 kg

HOME COMBI
25 -A (H-GB)

230 V / 50 Hz 230 V / 50 Hz 230 V / 50 Hz

T2/2A, 250V T2/2A, 250V T2/2A, 250V

105 W 110 W 120 W

2 W 2 W 3 W

IPX4D IPX4D IPX4D

HOME COMBI
30 -A (H-GB)

HOME COMBI
30 -A (H-GB)

HOME COMBI
35 -A (H-GB)

HOME COMBI
35 -A (H-GB)

0020224355_00 HOME Installation and maintenance instructions 49

Index

Index

A

Air/flue pipe ....................................................................... 12

Installing.........................................................................12

Air/flue pipe, installed ............................................................ 5

Article number ....................................................................... 7

B

Burner anti-cycling time ....................................................... 20

C

Calling up the fault memory................................................. 26

CE label................................................................................. 8

Check programmes........................................................... 30

Using..............................................................................16

Checking the burner ............................................................24

Checking the pre-charge pressure of the expansion

vessel ..................................................................................26

Cleaning the condensate siphon ......................................... 25

Cleaning the heat exchanger .............................................. 24

CO₂ content

Checking.................................................................. 20, 22

Combustion air ...................................................................... 5

Completing inspection work ................................................26

Completing maintenance work ............................................26

Completing repair work .......................................................29

Completing, repair work ......................................................29

Condensate drain pipework................................................. 12

Condensate siphon

Filling ............................................................................. 18

Controller............................................................................. 15

Controlling the bypass ......................................................... 21

Corrosion............................................................................... 5

D

Decommissioning................................................................ 29

Decommissioning the product .............................................29

Diagnostics codes

Using..............................................................................15

Documents ............................................................................7

Draining the product ............................................................26

E

Electricity ............................................................................... 5

Expansion relief valve .........................................................29

F

Fault codes.......................................................................... 26

Fault symbol........................................................................16

Flow rate-pressure curves ................................................... 21

Flow sensor.........................................................................29

Flue gas route .......................................................................5

Flue pipe equipment connection piece................................ 12

Front casing, closed .............................................................. 5

Frost ......................................................................................5

H

Handing over to the operator............................................... 22

I

Identification plate ................................................................. 7

If you smell gas .....................................................................4

Inspection work ............................................................. 22, 40

Installation site.......................................................................5

Intended use.......................................................................... 4

M

Mains connection ................................................................ 14

Maintenance work ......................................................... 22, 40

P

Power supply....................................................................... 14

Preparing the repair work .................................................... 26

Preparing, repair work .........................................................26

Pressure sensor .................................................................. 29

Pump ................................................................................... 21

Pump head..........................................................................28

Pump output

Setting............................................................................21

R

Regulations ........................................................................... 6

Removing the air intake pipe...............................................23

Removing the burner ........................................................... 23

Removing the flue pipe........................................................ 23

Removing the gas-air mixture unit....................................... 23

Removing the ignition transformer ...................................... 23

Removing the side section .................................................. 10

Replacing the burner ...........................................................26

Replacing the expansion vessel..........................................28

Replacing the gas valve ...................................................... 26

Replacing the heat exchanger............................................. 27

Replacing the main PCB ..................................................... 28

Replacing the PCB for the user interface............................ 29

Replacing, expansion vessel............................................... 28

Resetting the burner anti-cycling time................................. 21

S

Safety device......................................................................... 5

Schematic drawing................................................................5

Serial number........................................................................7

Setting the burner anti-cycling time ..................................... 20

Spare parts.......................................................................... 22

Switching on the product ..................................................... 18

T

Tool .......................................................................................6

Transport ............................................................................... 5

Transporting ..........................................................................8

Treating the heating water .................................................. 17

U

Unloading the box .................................................................8

Unpacking the product ..........................................................8

Using

Check programmes .......................................................16

Diagnostics codes.......................................................... 15

V

Voltage ..................................................................................5

W

Weight ...................................................................................9

50 Installation and maintenance instructions HOME 0020224355_00

0020224355_00 14.10.2015

Vaillant Ltd.

Nottingham Road Belper Derbyshire DE56 1JT
Telephone [phone] Telephone (renewables) 0207 022 0928
Vaillant Service Solutions 0330 100 3461 Spares Technical Enquiries 01773 596615

[e-mail] [e-mail]

www.vaillant.co.uk

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