Viessmann VITOWELL comfort User manual

Installation And Operation Manual
ELECTRIC STORAGE WATER HEATER
ENGLISH
Please read this manual carefully, before installation, usage and maintenance.
6194193 07/2023

1
Safety------------------------------------------------------------------2
General warnings ------------------------------------------------------------------------------------2
Key to symbols -------------------------------------------------------------------------------------2
General safety norms--------------------------------------------------------------------------------2
Specific safety norms for this appliance------------------------------------------------------------3
Appliance description--------------------------------------------------------4
Appliance profile-------------------------------------------------------------------------------------4
Appliance norms-------------------------------------------------------------------------------------6
Appliance installation--------------------------------------------------------6
Packing list------------------------------------------------------------------------------------------ 6
Installation norms (for the installer) ------------------------------------------------------------------6
Installing the appliance------------------------------------------------------------------------------6
Installation steps ------------------------------------------------------------------------------------7
User instructions----------------------------------------------------------- 10
Wiring diagram and technical parameters ---------------------------------13
Advice for user-------------------------------------------------------------------------------------10
Control and operating instructions-----------------------------------------------------------------10
Wiring diagram--------------------------------------------------------------------------------------13
Technical parameters-------------------------------------------------------------------------------14
Maintenance instructions---------------------------------------------------15
Maintenance regulations----------------------------------------------------------------------------15
Cleaning the outer parts-----------------------------------------------------------------------------15
Safety valves---------------------------------------------------------------------------------------15
Periodic maintenance-------------------------------------------------------------------------------15
Troubleshooting-----------------------------------------------------16
Fault analysis ---------------------------------------------------------------------------------------16
Contents

Safety
GENERAL WARNINGS
1. This manual is an integral and essential part of the appliance. It should be preserved with care and
transferred alongside the appliance if the latter is transferred to another owner or user and/or moved to
another location.
2. Carefully read the instructions and warnings contained in this manual. They provide important information
for the safe installation, use and maintenance of your new appliance.
3. The installation should be performed by a competent person in accordance with the instructions contained
herein.
4. The use of this appliance for purposes other than those specified is strictly forbidden. The manufacturer is
not to be held responsible for any damage due to improper, incorrect and unreasonable use or due to failure
to comply with the instructions set forth herein.
5. Installation, maintenance and all other interventions must be carried out by a competent person in full
conformity with the applicable legal regulations and the directions provided by the manufacturer.
6. Incorrect installation can cause personal injury, property damage and damage to animals. The
manufacturer will not be held responsible for such damage.
7. Keep all packing material (clips, plastic bags, polystyrene foam, etc.) out of children's reach as they are
hazardous.
8. This appliance is not intended for use by persons (including children) with reduced physical, sensory or
mental capabilities, or lack of experience and knowledge, unless they have been given supervision or
instruction concerning use of the appliance by a person responsible for their safety. Children should be
supervised to ensure that they do not play with the appliance.
9. It is strictly forbidden to touch the appliance barefoot or with wet hands or feet.
10. All repairs should be carried out by a competent person only, using only original spare parts. Failure to
comply with the above instructions could compromise safety and invalidate all liability on the part of the
manufacturer.
11. The appliance electrical connection should be made in accordance with the related provisions herein.
12. If the device that safeguards against excess pressure is supplied with the appliance, it must not be
tampered with and must be promptly replaced with appropriate devices if it is not in accordance with
regulations and legislation.
13. No inflammable items should be left in the vicinity of the appliance.
Key to symbols
Symbol Meaning
Failure to comply with this warning implies the risk of personal injury and even death
in some circumstances.
Failure to comply with this warning implies the risk of damage and even serious
damages to property, plants or animals in some circumstances.
It is obliged to keep to the general safety norms and appliance specifications.
General safety norms
Ref. Warning Risk Symbol
1
The heater must be fitted with reliable
grounding. Do not use the heater without any
reliable grounding. Do not connect the
grounding wire to the zero line or water pipe.
Electrocution
2

Ref. Warning Risk Symbol
3Do not use a 13 A socket which may cause your
wires to overheat, melt and fuse together, leading
to a short circuit. It should be wired directly to a
heater switch which is able to support higher
current.
A pressure relief device is to be fitted in the
installation at the cold water inlet. Risk of tank overpressure and explosion.
Electrocution from a damaged cable or
plug, or socket.
2Do not open or remove the appliance. Electrocution from live components;
personal injury from burns due to
overheated components or wounds
caused by sharp edges or protrusions.
4
Do not damage the power supply cable. Electrocution from live unsheathed wires.
5
Do not leave anything on top of the appliance. Personal injury from an object falling off the
appliance following vibrations
Damage to the appliance or any objects
underneath it due to the object falling off
following vibrations.
6
Do not climb onto the appliance. Personal injury due to the appliance falling.
Damage to the appliance or any objects
underneath it due to the appliance falling
off from its place of installation.
7
Do not attempt to clean the appliance without first
turning it off and unplugging it or switching the
dedicated switch off.
Electrocution from live components.
8
Install the appliance on a solid wall that is not
subjected to any vibrations. Appliance falling due to the wall giving way, or excessive noise during operation.
9
Make all electrical connections using conductors
with a suitable section. Fire due to overheating from electrical current passing through undersized cables.
10
11 Reset all the safety and control functions affected
by any intervention performed on the appliance
and make sure they operate correctly before
re-using the appliance.
Damage or shutdown of the appliance due
to out-of-control operation.
Safety
12 Before handling, empty all components that may
contain hot water. Personal injury from burns.
13 Descale the components, in accordance with the
instructions provided on the “safety data sheet" of
the product used, air the room, wear protective
clothing, avoid mixing different products, and
protect the appliance and surrounding objects.
Personal injury due to contact of the skin
or eyes with acidic substances, inhalation
or swallowing of harmful chemical agents.
Damage to the appliance or surrounding
objects due to corrosion caused by acidic
substances.
14 Do not use any insecticides, solvents or
aggressive detergents to clean the appliance. Damage to the plastic and painted parts.
Specific safety norms for this appliance
3

Appliance profile
Cube type C2 (Classic)
Model ABCD E
15L Cube C2 390 mm 360 mm 340 mm 100 mm 84 mm
30L Cube C2 470 mm 440 mm 395 mm 100 mm 103 mm
1 Upper panel
2 LED
3 Bottom panel
4 Temperature knob
5 Hot water outlet
6 Cold water inlet
7 ELCB electricity
protection*
8 Housing-rear
Model A B C D E
15L Cube D2 390 mm 360 mm 340 mm 100 mm 84 mm
30L Cube D2 470 mm 440 mm 395 mm 100 mm 103 mm
1 Upper panel
2 Bottom panel
3 Control panel
4 Hot water outlet
5 Cold water inlet
6 ELCB electricity
protection*
7 Housing-rear
Cube type D2 (Deluxe)
Appliance description
Cube type P2 (Premium)
1 Upper panel
2 LED
3 Bottom panel
4 Temperature knob
5 Hot water outlet
6 Cold water inlet
7 ELCB electricity
protection*
8 Housing-rear
Model A B C D E
15L Cube P2 390 mm 360 mm 340 mm 100 mm 84 mm
30L Cube P2 470 mm 440 mm 395 mm 100 mm 103 mm
4
*ELCB not available in some countries

1 Left panel
2 Magnesium anode
cover
3 Hot water outlet
4 Cold water inlet
5 Right panel
6 Temperature knob
7 LED
8 ELCB electricity protection*
9 Housing-rear
1 Left panel
2 Magnesium anode
cover
3 Hot water outlet
4 Cold water inlet
5 Right panel
6 Temperature knob
7 LED
8 ELCB electricity protection*
9 Housing-rear
Model A B C D E
Model A B C D E
Appliance description
Slim type C2 (Classic):
Slim type P2 (Premium):
5
*ELCB not available in some countries
20L Slim C2
15L Slim C2
30L Slim C2
630mm 280mm 280mm 100mm 140mm
550mm 260mm 260mm 100mm 130mm
680mm 320mm 320mm 100mm 160mm
20L Slim P2 630mm 280mm 100mm 140 mm
15L Slim P2 550mm 260mm
280mm
260mm 100mm 130mm
30L Slim P2 680mm 320mm 320mm 100mm 160mm
Slim type D2 (Deluxe):
1 Left panel
2 Magnesium anode
cover
3 Hot water outlet
4 Cold water inlet
5 Right panel
6 Temperature knob
7 Control Panel
8 ELCB electricity protection*
9 Housing-rear
Model A B C D E
30L Slim D2 680mm 320mm 320mm 100mm 160mm

Packing list
All water heaters are shipped with the following items. Please check them before installation.
No. Component description Qty.
1Water heater 1 set
2User’s manual1 copy
3Warranty card 1 copy (Vietnam)
4
Expansion tube 2 pcs
5
Screw 2 pcs
6
Pressure Relief Device
1 pc
7 Brackets
Installation norms (for the installer)
Follow the general warnings and the safety norms listed at the beginning of the text and keep to
all the instructions given under all circumstances.
The installation and set-up of the water heater must be carried out by a competent person in conformity with the applicable
norms in force and with any provisions set forth by local authorities and public health bodies.
The heater must be fitted with reliable grounding. Do not use the heater without any reliable grounding. Do not connect the
grounding wire to the zero line or water pipe.
The appliance heats water to a temperature below boiling point. It must be linked up to a mains water supply according to the
appliance performance levels and capacity.
Before connecting the appliance, it is first necessary to:
■Check whether the appliance characteristics (please refer to the data plate) meet the customer’s requirements.
■Make sure the installation conforms to the IP degree (of protection against the penetration of liquids) of the appliance according
to the applicable norms in force.
■Read the instructions provided on the packaging label and on the appliance data plate.
■Make sure the water tank is filled with water before turning on the appliance, manufacturer shall not be held responsible for any
damage and warranty shall be void if failure to do so.
This appliance is designed to be installed only inside buildings in compliance with the applicable norms in force.
Furthermore, installers are requested to keep to the following advice in the presence of:
■Damp: do not install the appliance in closed (unventilated) and damp rooms.
■Sunlight: do not expose the appliance to direct sun rays, even in the presence of windows.
■Dust/vapor/gas: do not install the appliance in the presence of particularly dangerous substances such as acidic vapor, dust or
those saturated with gas.
■Electrical discharges: do not install the appliance directly on electrical supplies that aren’t protected against sudden voltage
jumps.
In the case of walls made of bricks or perforated blocks, partition walls featuring limited static, or masonry different in some way
from those stated, you first need to carry out a preliminary static check of the supporting system.
The wall-mounting fastening hooks must be designed to support a weight that is three times higher than the weight of the water
heater filled with water.
Local norms could set forth restrictions regarding the installation in a bathroom environment. Therefore keep to the minimum
distances foreseen by the applicable norms in force.
Appliance norms
Implementation norms
IEC60335-1 Safety of household and similar electrical appliances---General requirements
IEC60335-2-21 Household and similar electrical appliances---Safety---Particular requirements for storage water heaters
Appliance installation
6
The appliance should be installed not too far from the point of use to limit heat dispersion along the piping.
Allow for a clearance of at least 50 cm to provide access to the electrical components, thus facilitating the maintenance
activities.
Cube/Slim20L: 1 pcs

Follow the general warnings and the safety norms listed at the beginning of the text and keep to
all the instructions given under all circumstances.
The installation and set-up of the water heater must be carried out by a competent person in conformity with the applicable
norms in force and with any provisions set forth by local authorities and public health bodies.
The heater must be fitted with reliable grounding. Do not use the heater without any reliable grounding. Do not connect the
grounding wire to the zero line or water pipe.
The appliance heats water to a temperature below boiling point. It must be linked up to a mains water supply according to the
appliance performance levels and capacity.
Before connecting the appliance, it is first necessary to:
■Check whether the appliance characteristics (please refer to the data plate) meet the customer’s requirements.
■Make sure the installation conforms to the IP degree (of protection against the penetration of liquids) of the appliance according
to the applicable norms in force.
■Read the instructions provided on the packaging label and on the appliance data plate.
■Make sure the water tank is filled with water before turning on the appliance, manufacturer shall not be held responsible for any
damage and warranty shall be void if failure to do so.
This appliance is designed to be installed only inside buildings in compliance with the applicable norms in force.
Furthermore, installers are requested to keep to the following advice in the presence of:
■Damp: do not install the appliance in closed (unventilated) and damp rooms.
■Sunlight: do not expose the appliance to direct sun rays, even in the presence of windows.
■Dust/vapor/gas: do not install the appliance in the presence of particularly dangerous substances such as acidic vapor, dust or
those saturated with gas.
■Electrical discharges: do not install the appliance directly on electrical supplies that aren’t protected against sudden voltage
jumps.
In the case of walls made of bricks or perforated blocks, partition walls featuring limited static, or masonry different in some way
from those stated, you first need to carry out a preliminary static check of the supporting system.
The wall-mounting fastening hooks must be designed to support a weight that is three times higher than the weight of the water
heater filled with water.
Local norms could set forth restrictions regarding the installation in a bathroom environment. Therefore keep to the minimum
distances foreseen by the applicable norms in force.
Installation steps
Cube type
1. Installing the expansion-bolt hooks
Drill two ø10 x 85 mm holes in the wall. Insert
expansion tubes into the holes, place the screws
through the hanging plate, and tighten the
screws with a screwdriver. Ensure hanging plate
is positioned vertically upward.
2. Remove baffles plate from hanging holes
Pry up the plastic baffle plates on the back of the
water heater that are covering the hanging holes
with a slotted screwdriver. Keep hanging holes
visible.
3. Hanging water heater
Lift the water heater, align its hanging holes with the hanging plate hooks. Fit the hanging holes onto hanging
plate hooks. Pull down the water heater to ensure secure installation.
Clearance space should be provided around the water heater as shown in the figure, to facilitate installation
and maintenance operation.
Appliance installation
7
The appliance should be installed not too far from the point of use to limit heat dispersion along the piping.
Allow for a clearance of at least 50 cm to provide access to the electrical components, thus facilitating the maintenance
activities.
≥ 80mm
≥ 80mm
≥ 160mm
≥ 80mm

Lift the water heater, align the square holes on the back with the hooks and attach them. Then pull down
the water heater to ensure the secure installation.
2. Hanging the water heater
Slim type
1. Installing expansion-bolts hook
Drill two ø10 x 85 mm holes in the wall. Insert expansion tubes into the holes, place the screws through the
hanging plate, and tighten the screws with a screwdriver. Ensure hanging plate is positioned vertically upward.
Clearance space should be provided around the water heater as shown in the figure, to facilitate
installation and maintenance operation.
Connect the water heater’s inlet and outlet with pipes or fittings that are able to withstand temperature in
excess of 80°C at a pressure above the working pressure. Therefore, we advise against the use of any
materials which cannot resist such high temperatures.
Connect the hydraulic line as shown in the figure. The outlet is on the left (red) and the inlet is on the
right (blue). Do not over-tighten the safety valve or alter the position of the safety valve without
authorization. It is essential to leave the safety release valve open to the atmosphere.
A cold pipe is connected under the valve and a hot pipe is connected with the valve outlet. (Wrap all
hydraulic connections with PTFE tape.) Fill the appliance with water and check if the appliance or the
hydraulic line leaks. If no leakage is detected, switch on the electricity mains and start the trial run.
If the network pressure is closed to the rated valve pressure, it will be necessary to apply a pressure
reducer far away from the appliance.
To avoid any possible damage to the mixer units (taps or shower), it is necessary to drain any impurities
from the pipes. Otherwise, impurities may cause damages to the mixer units.
Appliance installation
8
20L SLIM 15/30L SLIM
≥ 80mm
≥ 80mm ≥ 500mm
≥ 160mm

Electrical connection
Before performing any operations, disconnect the appliance from the electricity mains using the external switch.
For greater safety, authorize qualified personnel to carry out a careful inspection of the electrical system,
ensuring it complies with the applicable norms in force, because the appliance manufacturer will not be held
responsible for any damage caused by the lack of earthing of the system or for improper wiring.
Check that the supply system is suitable for the maximum power absorbed by the water heater (please refer to
the data plate) and that the cross-section of the electrical connection cables is suitable and complies with current
laws.
The use of multi-plugs, extensions or adaptors is strictly prohibited.
It is strictly forbidden to use the piping from the plumbing, heating and gas systems for the appliance earthing
connection.
Starting and testing the appliance
Before powering the appliance, fill the tank up with water.
The filling is carried out by turning on the domestic mains tap and the hot water tap, until the air is completely
released.
Visually check for water leaks, including flanges, and slightly tighten it if necessary.
Turn the knob to adjust the setting temperature (MAX position recommended). The red color heating LED keeps
on during the water heating process. After the preset working temperature is reached, the thermostat will stop
the heating element automatically.
Connect the water heater’s inlet and outlet with pipes or fittings that are able to withstand temperature in
excess of 80°C at a pressure above the working pressure. Therefore, we advise against the use of any
materials which cannot resist such high temperatures.
Connect the hydraulic line as shown in the figure. The outlet is on the left (red) and the inlet is on the
right (blue). Do not over-tighten the safety valve or alter the position of the safety valve without
authorization. It is essential to leave the safety release valve open to the atmosphere.
A cold pipe is connected under the valve and a hot pipe is connected with the valve outlet. (Wrap all
hydraulic connections with PTFE tape.) Fill the appliance with water and check if the appliance or the
hydraulic line leaks. If no leakage is detected, switch on the electricity mains and start the trial run.
If the network pressure is closed to the rated valve pressure, it will be necessary to apply a pressure
reducer far away from the appliance.
To avoid any possible damage to the mixer units (taps or shower), it is necessary to drain any impurities
from the pipes. Otherwise, impurities may cause damages to the mixer units.
Appliance installation
9
Hydraulic connection