STIEBEL ELTRON HSBC 225 S Specification sheet

Integral cylinder 2
HSBC 225 S
Dieses Produkt ist nur für gut isolierte Räume oder
für den gelegentlichen Gebrauch geeignet.
This product is only suitable for well insulated
spaces or occasional use.
Ce produit convient uniquement aux locaux bien
isolés ou à un usage occasionnel.
Dit product is alleen geschikt voor goed geïsoleer-
de ruimtes of voor occasioneel gebruik.
Tento výrobek je vhodný pouze pro dobře izolo-
vané prostory nebo příležitostné použití.
Tento produkt je určený len do dobre izolovaných
priestorov alebo len na príležitostné použitie.
Produkt nadaje się wyłącznie do dobrze zaizolo-
wanych pomieszczeń lub do okazjonalnego kor-
zystania.
A termék kizárólag megfelelően szigetelt helyisé-
gekben vagy alkalomszerűen használható.
Operation and installation

Table of contents
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1 Special information................................................... 3
2 General information.................................................. 3
2.1 Symbols in this document ................................ 3
2.2 Units of measurement ...................................... 3
3 Safety........................................................................ 3
3.1 Structure of the warning notices....................... 3
3.2 Intended use .................................................... 4
3.3 Foreseeable misuse.......................................... 4
3.4 Safety instructions............................................ 4
4 Appliance description................................................ 4
4.1 Appliance compatibility.................................... 4
4.2 Standard delivery ............................................. 5
4.3 Required accessories........................................ 5
4.4 Optional accessories......................................... 5
5 Transportation (qualified contractors) ....................... 5
6 Storage ..................................................................... 5
7 Installation (qualified contractors)............................. 5
7.1 Installation site................................................. 5
7.2 Minimum clearances........................................ 5
7.3 Siting the appliance ......................................... 6
7.4 DHW connection............................................... 6
7.5 Heating water connection................................. 6
7.6 Filling the system ............................................. 7
8 Commissioning (qualified contractors) ...................... 8
8.1 Check to be carried out before commissioning
the heat pump manager................................... 8
8.2 Commissioning the heat pump manager .......... 8
8.3 Appliance handover ......................................... 8
9 Settings..................................................................... 8
10 Cleaning (operators) ................................................. 9
11 Maintenance (qualified contractors) .......................... 9
11.1 Draining the appliance..................................... 9
11.2 Flushing the system ......................................... 9
12 Troubleshooting (operators)...................................... 10
13 Troubleshooting (qualified contractors)..................... 11
14 Shutting down the system ......................................... 11
15 Specification ............................................................. 11
15.1 Dimensions and connections ............................ 11
15.2 Installation example......................................... 13
15.3 Hydraulic diagram ........................................... 13
15.4 Data table ........................................................ 13
16 Logbook for installation, commissioning and main-
tenance..................................................................... 14
16.1 Commissioning information ............................. 15
16.2 Maintenance interval log.................................. 16
17 Guarantee ................................................................ 18
18 Environment and recycling ....................................... 18

Special information
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1 Special information
– The appliance may be used by children over
8 years of age and persons with reduced
physical, sensory or mental capabilities or a
lack of experience and expertise, provided
that they are supervised or they have been
instructed on how to use the appliance
safely and have understood the potential
risks. Children must never play with the ap-
pliance. Cleaning and user maintenance
must not be carried out by children without
supervision.
– Observe all applicable national and regional
regulations and instructions.
– Observe minimum clearances (see chapter
Minimum clearances [}5] ).
– Only a qualified contractor should carry out
installation, commissioning, maintenance
and repair of the appliance.
– Always fill the appliance with water before
switching it on.
– The appliance must be installed in compli-
ance with the applicable building regula-
tions.
– The terminal box is subject to continuous
voltage. Prior to any electrical work, always
disconnect the power supply and safeguard
against reconnection during ongoing work.
– The connection to the power supply must be
in the form of a permanent connection. En-
sure the appliance can be separated from
the power supply by an isolator that discon-
nects all poles with at least 3mm contact
separation.
DHW cylinder
– Drain the appliance as described in chapter
Draining the appliance [}9] .
– Observe the maximum permissible pressure
(see chapter Data table [}13] ).
– The appliance's DHW cylinder is pressur-
ised. During the heat-up process, expansion
water will drip from the safety valve.
– Regularly activate the safety valves to pre-
vent them from seizing up, e.g.due to
limescale deposits.
– The safety valve drain connections must re-
main open to atmosphere.
– The safety valve overflows must not be
sealed or blocked off.
2 General information
Read these instructions carefully before using the
appliance and retain them for future reference.
Pass on these instructions along with the appliance
as necessary.
2.1 Symbols in this document
Symbol Meaning
This symbol indicates possible property damage,
equipment damage, consequential damage or envir-
onmental damage.
General information is indicated by the adjacent
symbol.

This symbol indicates that you have to do something.

This symbol indicates that you must fulfil certain
prerequisites before you perform the following
steps.

This symbol indicates a result or intermediate result.

These symbols show you the software menu level (in
this example level3).
This symbol indicates a reference to the correspond-
ing page number (page11 in this example).
2.2 Units of measurement
All measurements are given in mm unless stated otherwise.
3 Safety
3.1 Structure of the warning notices
3.1.1 Section-specific warning notices
Section-specific warning notices apply to all steps in the section.
Injury
CAUTION
Type and source of risk
Consequence(s) of failure to observe the warning no-
tice
uHazard prevention measure(s)
Property damage, consequential losses, environmental
pollution
NOTICE
Type and source of risk
Consequence(s) of failure to observe the warning no-
tice
uHazard prevention measure(s)
3.1.2 Embedded warning notices
Embedded warning notices apply only to the step immediately
following the notice.
uSIGNAL WORD: Consequence(s) of failure to observe the
warning notice. Hazard prevention measure(s). Step to
which the warning notice refers
en

Appliance description
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3.1.3 Key to symbols
Symbol Type of risk
Injury
Electrocution
Burns, scalding
3.1.4 Signal words
Signal
word
Meaning
DANGER Failure to observe this information will result in
death or serious injury.
WARNING Failure to observe this information may result in
death or serious injury.
CAUTION Failure to observe this information may result in
moderate or minor injury.
NOTICE Failure to observe this information may result in
property damage, consequential losses or environ-
mental damage.
3.2 Intended use
The appliance is used for DHW heating and for heating rooms.
The appliance is intended for domestic use. It can be used safely
by untrained persons. The appliance can also be used in non-
domestic environments, e.g.in small businesses, as long as it is
used in the same way.
Observation of these instructions and of instructions for any ac-
cessories used is also part of the intended use of this appliance.
3.3 Foreseeable misuse
Any other use beyond that described shall be deemed to be out-
side the intended use.
Using the appliance for heating fluids other than water or for
water supplemented with chemicals, such as brine, is also
deemed inappropriate.
Never use the appliance for cooling.
3.4 Safety instructions
Injury
– There is a risk of scalding at outlet temperatures in excess
of 43°C.
– The appliance may be used by children over 8 years of age
and persons with reduced physical, sensory or mental cap-
abilities or a lack of experience and expertise, provided that
they are supervised or they have been instructed on how to
use the appliance safely and have understood the potential
risks. Children must never play with the appliance. Cleaning
and user maintenance must not be carried out by children
without supervision.
– The safety valve overflows must not be sealed or blocked
off.
– It is not permitted to carry out modifications or conversions
on the appliance.
– Unsuitable spare parts and accessories may jeopardise user
and appliance safety. Always use original spare parts and
original accessories.
– We recommend a DHW temperature of at least 55°C to en-
sure optimum hygiene conditions. If operating the appli-
ance at a lower DHW temperature, regularly heat the cylin-
der content to 60°C.
Property damage, consequential losses, environmental
pollution
– The DHW cylinder is under supply pressure. If no expansion
vessel is installed, expansion water will drip from the safety
valve during heat-up. If water continues to drip after heat-
ing has stopped, inform your qualified contractor.
– Consult building regulation G3.
4 Appliance description
The buffer cylinder and DHW cylinder with indirect coil are ar-
ranged one on top of the other. The indirect coil transfers the
heat of the heating water from the heat pump to the DHW.
The appliance is connected hydraulically and electrically to the
heat pump. In addition to the DHW cylinder and the buffer cylin-
der, further system components are integrated:
– Cylinder charging pump
– 3/2-way heating diverter valve
– Highly efficient circulation pump for a heating circuit
without mixer
– Heat pump manager
DHW cylinder
The heating water heated by the heat pump is pumped through
an indirect coil inside the DHW cylinder. The heat channelled
through the indirect coil is thus transferred to the domestic hot
water. The integral heat pump manager regulates the DHW
heating to the required temperature.
Buffer cylinder
The steel cylinder provides hydraulic separation between the
flow rates of heat pump and heating circuit. The heating water
heated by the heat pump is transferred into the buffer cylinder
by the cylinder charging pump. When a demand is issued, the
integral circulation pump delivers the heating water to the heat-
ing circuit.
Heat pump manager (WPM)
The system is controlled by means of the integral heat pump
manager.
The heat pump manager is suitable for the control of a direct
heating circuit and a heating circuit with mixer.
You can set the times and temperatures for heating operation
and DHW heating.
uPlease observe the instructions for the heat pump manager.
Product registration
Register your product on the STIEBEL ELTRON website. Your
complete data allows us to provide quick assistance if a guaran-
tee claim is made. Our customer service department will take
care of your system and ensure smooth handling.
4.1 Appliance compatibility
The appliance can be operated in conjunction with the following
heat pumps:
– WPL 15-25 A (C) (S)
– WPL-A 05-07 HK 230 Premium

Transportation (qualified contractors)
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4.2 Standard delivery
– Instructions for the WPM heat pump manager
– 1x outside temperature sensor AF PT
– 1x T&P valve
– 2x sensor conduit Ø6mm / Ø8mm
– 3x adjustable feet
– 1x G3 kit
– 1x multibloc
– 1x drain pipe
– 1x tundish
– 1x DHW outlet
– 1x circulation pump
– 2x drain valves
– 1x drain valve/safety valve for the buffer cylinder
– 1x 3-way motorised valve
– 1x DHW circulation pump
– 1x expansion vessel (not fitted at the factory)
4.3 Required accessories
Safety assemblies and pressure reducers are available to suit
the prevailing supply pressure. These type-tested safety assem-
blies protect the appliance against impermissible excess pres-
sure.
4.4 Optional accessories
– 1× pressure reducer
– 1× remote control for heating operation
– 1× high limit safety cut-out STB-FB
– 1× water softening device HZEA
5 Transportation (qualified contract-
ors)
NOTICE
Property damage
Lifting the appliance by the pipe connectors, valves,
etc. may damage the appliance.
uNever lift the appliance by the pipe connectors,
valves, etc.
uTransport the appliance at temperatures between -20°C
and +60°C.
uTransport the appliance in its original packaging.
6 Storage
uStore the appliance at temperatures between -20°C and
+60°C.
7 Installation (qualified contractors)
NOTICE
Property damage
The heating system to which the appliance is connec-
ted must be installed by a qualified contractor.
NOTICE
Incorrect water connection and installation work may
cause property damage.
uCarry out all water connection and installation
work in accordance with regulations.
7.1 Installation site
NOTICE
Property damage
Siting the appliance in a room with high humidity
may damage the appliance.
uNever install the appliance in wet rooms.
The installation site must fulfil the following requirements:
– Free from the risk of frost
– Dry
– Adequate room height
The substrate on which the appliance is to be installed must
meet the following conditions:
– Water resistant
– Horizontal
– Level
– Fixed
– Permanent
– Sufficient load bearing capacity (for weight of the appliance,
see chapter Data table [}13] ).
7.2 Minimum clearances
≥400
≥50
≥500
≥400
≥150
D0000111787
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Installation (qualified contractors)
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uMaintain the minimum clearances in order to ensure
trouble-free operation of the appliance and to allow enough
space for maintenance work.
uEnsure that there is sufficient space to lay the drain pipe
from the appliance to a location outside the building in ac-
cordance with building regulation G3.
7.3 Siting the appliance
uObserve chapter Minimum clearances [}5] .
The appliance is equipped with three factory-fitted adjustable
feet. Use the adjustable feet to compensate for any unevenness
in the floor.
uUnscrew the adjustable feet at least 15mm.
uAdjust the adjustable feet so that the appliance is stable and
level.
7.4 DHW connection
NOTICE
Property damage
If the pressure in the DHW cylinder exceeds the max-
imum permissible pressure, the water may be dis-
charged from the tap at excessively high pressure:
uEnsure that the maximum permissible pressure is
not exceeded (see chapter Data table [}13] ).
NOTICE
Property damage
An open (non-pressurised) tap will not withstand the
water pressure.
uOperate the appliance with pressure taps.
uUse suitable pipes.
uUse a suitable thread sealant.
uSeal off unused connection apertures.
üThe cold water line is made from hot-dip galvanised steel,
stainless steel, copper or plastic.
üThe DHW line is made from stainless steel, copper or
plastic.
uNOTICE:Foreign bodies, such as welding pearls, rust or
sealing material, can impair the operational reliability of
the appliance. Flush the pipework thoroughly before con-
necting the appliance.
7.4.1 Water connection
uUse suitable pipes.
uUse a suitable thread sealant.
uSeal off unused connection apertures.
uConnect the cold water line to the cold water inlet (see
chapter Installation example [}13] ).
uConnect the DHW line to the DHW outlet (see chapter In-
stallation example [}13] ).
uInstall the expansion vessel.
7.4.2 Drain pipe
Drain pipes must be temperature-resistant in ac-
cordance with building regulation G3.
The end of the outlet pipe must be in a safe and
clearly visible location.
For further information, contact your local authority
planning department.
Permissible drain pipe materials:
– Metal
Drain from a low height (up to 100mm above outside areas):
– To prevent contact and ensure visibility, a wire mesh or
similar safeguard must be fitted in outside areas where
children play or may come into contact with drain pipes.
Drain from a greater height:
– The drain pipe can be routed via a metal funnel and a metal
downpipe.
– The drain can also be laid on a temperature-resistant roof.
The end of the drain pipe must be at least 3m away from
any plastic guttering. The tundish must be clearly visible.
If multiple systems are connected by a split drain pipe:
– The split drain pipe must be at least one size larger than the
biggest drain pipe being connected.
uSize the drain pipe so that water can drain off unimpeded
when the T&P valve is fully opened (see chapter Hydraulic
diagram [}13] ).
uEnsure that the drain pipe of the T&P valve is open to the
atmosphere.
uInstall the T&P valve drain pipe with a constant fall to the
drain (see chapter Hydraulic diagram [}13] ).
uSecure the drain pipe to prevent any movement in the event
of water being discharged.
7.5 Heating water connection
NOTICE
Property damage
The heating system to which the appliance is connec-
ted must be installed by a qualified contractor.
NOTICE
Incorrect water connection and installation work may
cause property damage.
uCarry out all water connection and installation
work in accordance with regulations.
NOTICE
Property damage
When fitting additional shut-off valves, install a fur-
ther safety valve in an accessible location on the heat
generator itself or in the flow line in close proximity
to the heat generator. There must not be a shut-off
valve between the heat generator and the safety
valve.

Installation (qualified contractors)
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Heating circuit oxygen diffusion
NOTICE
Property damage
In underfloor heating systems with plastic pipes that
are permeable to oxygen and in open vented heating
systems, oxygen diffusion may lead to corrosion on
the steel components of the heating system (e.g. on
the indirect coil of the DHW cylinder, on buffer cylin-
ders, steel radiators or steel pipes).
uAvoid open vented heating systems and under-
floor heating systems with plastic pipes that are
permeable to oxygen.
NOTICE
Property damage
The products of corrosion (e.g. rusty sludge) can
settle in the heating system components, which may
result in a lower output or fault shutdowns due to re-
duced cross-sections.
Supply lines
The maximum permissible line length between the appliance
and the heat pump will vary, depending on the version of the
heating system (pressure drop). As a standard value, assume a
maximum line length of 10m and a pipe diameter of 22-28mm.
uProtect the flow and return lines against frost with sufficient
thermal insulation. The thermal insulation must be at least
twice as thick as the diameter of the pipe. Provide thermal
insulation in accordance with applicable regulations.
uAlso protect all supply lines against humidity, damage and
UV radiation by means of a conduit.
Pressure differential:
If the available external pressure difference is exceeded, the
pressure drop in the heating system could result in a reduced
heating output.
uWhen sizing the pipes, ensure that the available external
pressure differential is not exceeded (see chapter Data table
[}13] ).
uWhen calculating the pressure drops, take account of the
flow and return lines and the pressure drop of the heat
pump. The pressure drop must be covered by the available
pressure differential.
7.5.1 Installing the heating water line
uUse suitable pipes.
uUse a suitable thread sealant.
uSeal off unused connection apertures.
uNOTICE:Foreign bodies, such as welding pearls, rust or
sealing material, can impair the operational reliability of
the appliance. Flush the pipework thoroughly before con-
necting the appliance.
uInstall suitable pipes at the connections for the radiator and
heat pump circuits (see chapter Installation example
[}13] ).
7.6 Filling the system
NOTICE
uNever switch on the power before filling the sys-
tem.
uFirst fill the appliance's DHW cylinder, then the
buffer cylinder.
7.6.1 Filling the DHW cylinder
uCheck that all connections are seated correctly and not leak-
ing.
uOpen a DHW valve of the draw-off point that is furthest
away from the appliance.
uLeave the DHW valve open until the appliance is full and the
pipes are free of air and dirt.
uClose the DHW valve.
uTo remove residual air from the pipes, open all downstream
DHW valves.
uClose all DHW valves.
uCarry out a tightness check.
uTo open the T&P valve, turn it anti-clockwise.
uCheck that water can flow unimpeded through the drain
pipe to the drain.
uTo close the T&P valve, continue turning the rotary selector
anti-clockwise until the T&P valve closes.
7.6.2 Heating system
The heating system is filled with drinking water. To prevent
damage to the heating system, comply with the following limits.
Unit Value
Water hardness °dH ≤3
pH value 6.5-8.5
Chloride mg/l <30
You can find out the water hardness and the chlorine value in
the fill water from the local water supplier.
uObserve local requirements (e.g. VDI2035 in Germany).
We do not recommend desalinating the fill water, as this may
cause a negative change in the pH value.
uIf you desalinate the fill water or the pH value of the fill wa-
ter is less than 8.2, check the pH value 8 to 12weeks after
installation, every time the system is topped up and the next
time it is serviced.
uDo not add inhibitors or additives to the filling water.
Accessories for water softening
If you need to soften the fill water, you can use the following
product.
– Water softening device HZEA
– HZEN replacement cartridge
uRecheck these limits 8-12weeks after commissioning, every
time the system is topped up and during the annual service.
Appliance in low-occupancy buildings
During regular operation, the connection lines and the system
are protected by the frost protection function of the appliance.
en

Commissioning (qualified contractors)
8 | www.stiebel-eltron.com
If the appliance is disconnected from the power supply for a
longer period of time (shutdown, prolonged power failure),
drain the appliance on the water side. Otherwise the appliance
is not protected against frost.
If it is not possible to detect power failures (for example if the
system is in a holiday home left vacant for extended periods of
time), the following protective measure can be taken.
uAdd a suitable concentration of ethylene glycol to the fill
water (20-40% by vol.). Observe the instructions for the an-
tifreeze. Only use antifreeze products which have been ap-
proved by us.
uPlease note that antifreeze changes the density and viscosity
of the fill water.
Product des-
ignation
MEG 10 Heat transfer medium as concentrate based on
ethylene glycol
MEG 30 Heat transfer medium as concentrate based on
ethylene glycol
Filling the heating system
uActivate the following parameters in the heat pump man-
ager.
Parameter
DIAGNOSIS/ RELAY TEST SYSTEM/ DRAIN HYD
üThe appliance is disconnected from the power supply with
omnipolar isolation.
uCheck that all connections are seated correctly and not leak-
ing.
uNOTICE:Glycol residues in the hoses can lead to acidifica-
tion of the heating water. This can result in corrosion and
malfunction. Use separate hoses for glycol and heating wa-
ter.
uFill the heating system via the drain valve and a filling hose
(not supplied).
uVent the pipework via the air vent valve on the heat pump.
8 Commissioning (qualified contract-
ors)
Our customer support can assist with commissioning.
If this appliance is intended for commercial use, observe the
rules of the relevant Health & Safety at Work Act during com-
missioning. For further details, check with your local author-
ising body (e.g. TÜV).
uSwitch on the power supply to the appliance.
8.1 Check to be carried out before commissioning
the heat pump manager
NOTICE
Property damage
If the heating water in underfloor heating systems is
too hot, it can damage the floor covering.
uWith underfloor heating systems, observe the
maximum permissible temperature for the un-
derfloor heating system.
uCheck that the heating system is filled to the correct pres-
sure and the quick-action air vent valve is closed.
uCheck whether the outside sensor is correctly placed and
connected.
uCheck whether the power supply is connected correctly.
uCheck whether the signal cable to the heat pump (bus
cable) is correctly connected.
8.2 Commissioning the heat pump manager
uCommission the heat pump manager and make all settings
in accordance with the heat pump manager commissioning
instructions.
With the "PARALLEL MODE" setting, the charging
pump is also activated in DHW mode.
uFor DHW mode, ensure that the "PARALLEL
MODE" option is set in the heat pump manager.
uActivate the following parameters in the heat pump man-
ager.
Parameter Setting
SETTINGS/ DHW/ STANDARD SETTING/ DHW
MODE PARALLEL OPERATION
On appliances with a single-phase connection, set
the heat pump manager as follows for calculating
the amount of heat.
uActivate the following parameters in the heat pump man-
ager.
Parameter Setting
SETTINGS/ HEATING/ ELECTRIC BOOSTER
HEATER/ NUMBER OF STAGES 2
8.3 Appliance handover
uExplain the functions of the appliance to the user. Show the
user how to operate the appliance.
uMake users aware of potential dangers.
uHand over these instructions and, if applicable, the instruc-
tions for any accessories.
uEnter your contact details in the logbook for installation,
commissioning and maintenance, which can be found at
the end of these instructions.
9 Settings
NOTICE
Property damage
The system's active frost protection is not guaranteed
if the power supply is interrupted.
uNever interrupt the power supply even outside
the heating season.
The heat pump manager has an automatic summer/
winter changeover so you can leave the system
switched on in summer.
The system is controlled by means of the integral heat pump
manager.
uObserve the relevant operating and installation instructions.

Cleaning (operators)
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OKMENU
D0000064711
10 Cleaning (operators)
NOTICE
Property damage
Unsuitable cleaning agents can contaminate the DHW
and damage the product.
uNever use cleaning agents that contain chlorine.
uNever use abrasive or corrosive cleaning agents. A damp
cloth is sufficient for cleaning the appliance.
Almost every type of water will deposit limescale at high tem-
peratures. Limescale will settle inside the appliance and affect
its function and service life. The heating elements must there-
fore be descaled if necessary. A qualified contractor who is
aware of the local water quality will tell you when the next de-
scaling is due.
uCheck the taps regularly. Limescale deposits at the tap out-
lets can be removed using commercially available descaling
agents.
uRegularly activate the safety valve to prevent it from becom-
ing stuck, e.g.due to limescale deposits.
11 Maintenance (qualified contractors)
WARNING
Electrocution
Incorrect electrical connection and installation work
may lead to serious injury due to electrocution.
uCarry out all electrical connection and installation
work in accordance with national and regional
regulations.
uEnsure the appliance can be disconnected from
the power supply by an isolator with at least
3mm omnipolar contact separation.
uDrain the expansion vessel before checking the
pre-charge pressure.
uBefore removing the expansion vessel, depres-
surise the DHW cylinder and drain 10-20l of
water via the drain valve at the bottom of the
DHW cylinder.
Component Activity Interval
Valves Check all valves. Annually
Component Activity Interval
Expansion vessel Drain the expansion
vessel. Check the
pre-charge pressure
of the expansion
vessel. If the pre-
charge pressure of
the expansion vessel
is not 3bar, restore
the value.
Annually
Dirt trap Remove, clean and
replace the dirt trap. Annually
DHW cylinder Close the shut-off
valve in the cold wa-
ter inlet. To depres-
surise the DHW cyl-
inder, open a DHW
valve on the next
draw-off point.
Annually
Pipes and drain
hoses Check the pipes and drain connections. Annually
Electrical connec-
tions Check the electrical connections. Annually
Taps Check the taps. Annually
11.1 Draining the appliance
WARNING
Burns
Hot water may escape when draining the appliance.
uWear heat-resistant protective gloves.
WARNING
Burns
The water temperature in the cylinder can be up to
70°C and may cause scalding.
uOpen a DHW valve.
uAllow the water to run at the maximum pressure
and temperature setting for at least 3minutes
before draining the appliance.
uClose the DHW valve.
Draining must be carried out in compliance with the
applicable building regulations.
11.1.1 Draining the buffer cylinder
uIsolate the appliance from the power supply.
uDrain the buffer cylinder via the drain valve in the lowest
installed pipe.
11.1.2 Draining the DHW cylinder
uClose the shut-off valve in the cold water inlet.
uOpen a DHW valve on a draw-off point.
uDrain the DHW cylinder via the drain valve in the cold water
line.
11.2 Flushing the system
uIf the system requires flushing, allow at least 50l of water
to run from the DHW cylinder at the greatest possible flow
rate.
uClose the DHW valves on the draw-off points.
uDrain the appliance (see chapter Draining the appliance
[}9] ).
en

Troubleshooting (operators)
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12 Troubleshooting (operators)
DHW cylinder
Fault Possible cause Remedy
The appliance does
not supply hot wa-
ter.
No voltage at the
appliance. Check that the appli- ance is connected to
the power supply.
A fuse in the distri-
bution board has
blown.
Check that the appli-
ance is connected to
the power supply. If
required, disconnect
the appliance from
the power supply
and replace the
fuses/reset the
MCBs. Reconnect
the appliance to the
power supply.
If the fuse/MCB
blows/trips again,
notify a qualified
contractor.
The DHW line is
leaking. Notify a qualified contractor.
The appliance does
not supply enough
hot water.
Your household has
high DHW consump-
tion.
Increase the tem-
perature setting to
70°C. Observe the
instructions for the
heat pump man-
ager.
You require an ap-
pliance with a larger
capacity.
The DHW temperat-
ure is not high
enough.
The temperature
setting is not high
enough.
Increase the tem-
perature setting to
70°C. Observe the
instructions for the
heat pump man-
ager.
The mixer tap is
faulty. Notify a qualified contractor.
The safety switch or
earth switch trips
repeatedly.
There is an electrical
fault. Isolate the appliance from the power sup-
ply.
Notify a qualified
contractor.
Very hot water is
continuously leaking
from the tundish.
The high limit safety
cut-out, temperat-
ure controller or
T&P valve is not
working correctly.
Isolate the appliance
from the power sup-
ply. Also isolate all
units indirectly con-
nected to the sys-
tem.
Notify a qualified
contractor.
Banging noises
come from the pipes
when the DHW
valves are closed.
If a DHW valve is
closed too quickly,
the pressure in the
pipes increases rap-
idly.
If the noises are an-
noying, arrange for
an expansion vessel
to be installed.
Notify a qualified
contractor.
The high limit safety
cut-out trips. Incorrect wiring. Reduce the temper- ature setting. Please
observe the instruc-
tions for the heat
pump manager.
If operating the ap-
pliance is still not
possible, notify a
qualified contractor.
The temperature
controller is not
working correctly.
Fault Possible cause Remedy
The high limit safety
cut-out trips. Incorrect wiring. Perform the actions listed in the chapter
link "Resetting the
safety temperature
controller". Reduce
the temperature set-
ting (see chapter
"Temperature set-
ting").
If operating the ap-
pliance is still not
possible, notify a
qualified contractor.
The immersion
heater or cylinder
temperature con-
troller is not work-
ing properly.
The temperature
setting is too high.
Buffer cylinder
Fault Possible cause Remedy
The heating system
does not heat up. A fuse in the distri- bution board has
blown.
Check whether the
fuses/MCBs in your
distribution board
have blown. If re-
quired, disconnect
the appliance from
the power supply
and replace the
fuses/reset the
MCBs. Reconnect
the appliance to the
power supply.
Contact your quali-
fied contractor if the
fuse/MCB blows/
trips again after the
appliance is connec-
ted to the power
supply.
The heating system
contains air. Vent the heating system as described
in the instructions
for the heat pump.
The heating circuit
pump is out of oper-
ation.
Notify a qualified
contractor.
The non-return
valves are set incor-
rectly.
The safety valve of
the heating system
is dripping.
The expansion ves-
sel is faulty. Notify a qualified contractor.
The safety valve is
faulty.
The pressure in the
heating system is
too high.
The heating circuit
must be refilled fre-
quently.
The heating system
is leaking. Notify a qualified contractor.
uIf you cannot remedy the fault, contact your qualified con-
tractor.
The contact details for the qualified contractor can be found in
the logbook for installation, commissioning and maintenance at
the end of these instructions.
uTo facilitate and speed up your enquiry, please provide the
qualified contractor with the number from the type plate.
The type plate is located on the front of the appliance above the
heat pump manager.