Herz pelletstar CONDENSATION 10 User manual

OPERATING INSTRUCTIONS
Pellet boiler
pelletstar CONDENSATION
10-60

Introduction
2 Betriebsanleitung_pelletstar_10-60_CONDENSATION_T-CONTROl_2_HZS5215_eng_V1.2
INTRODUCTION
Dear Customer!
Your heating equipment is powered using HERZ pelletstar boiler equipment and we are delighted to be able
to welcome you into the large circle of satisfied operators of HERZ equipment. The HERZ boiler is the result
of years of experience and continuous improvement. Please remember that in order to be able to work
properly, a well-designed product also needs to be operated and maintained correctly. Please therefore read
this documentation carefully –you will find it worthwhile. Please pay particular attention to the safety notes. It
is a precondition of any warranty claim that all operating rules are maintained. In the event of any faults or
defects, please contact your heating specialist or the HERZ Customer Service department.
Yours sincerely
HERZ –Energietechnik
Warranty / Guarantee (general information)
HERZ boiler systems come with a 5-year warranty on the boiler body, storage tanks and HERZ solar
collectors. We generally guarantee freedom from defects of mobile objects purchased for a period of 2 years,
to a maximum of 6.000 hours of operation. For non-moving purchased items, the guarantee is generally for a
period of 3 years to a maximum for 9.000 hours of operation. Wearing parts are not covered by the
guarantee/warranty. Furthermore, claims under warranty will not be applicable, if commissioning
1
is not
carried out by specialist personnel authorised by HERZ, with a heating load of less than 70% of the rated
output (manually stoked boilers must always be operated with a sufficiently dimensioned buffer storage
tank), if hydraulic diagrams
2
not recommended by HERZ are used and if a non-prescribed fuel as well as
pellets for non-industrial use according to ENplus, Swisspellet, DINplus resp. EN 17225-2; wood chips
according to EN 17225-1/4 with specification and classes: A1, A2, B1 resp. G30, G50 resp. log wood is
used
3
.
All business is subject to the general terms and conditions of HERZ Energietechnik GmbH as well as the
agreements confirmed with the order acceptance.
These are available at www.herz-energie.at .
Any claim to warranty services requires maintenance to be carried out on an annual basis by
specialist personnel authorised by HERZ.
The general warranty period will not be extended if work is carried out under warranty. A guarantee claim
does not delay the due date of our accounts. We will only provide a guarantee if all the payments owed to us
for the product supplied have been made.
The warranty will be carried out at our discretion by repairing the item purchased or replacing any defective
parts, by exchanging the item or by reducing the price. Parts or goods replaced are to be returned to us at
our request free of charge. Wages and costs paid out in connection with installation and removal are to be
paid for by the purchaser. The same applies to all warranty services.
The Supplier shall under no circumstances be liable to the Customer, for any direct, indirect or consequential
costs incurred by the Customer for works carried out on HERZ equipment.
This document is the translation from the German original. The reproduction or copying, even of extracts,
may only be undertaken with the permission of the company HERZ©.
Subject to technical modifications.
Version 02/2021
1
Maintenance by manufacturer
2
Recommended hydraulic diagrams can be found in the installation manual, while hydraulic balancing will be carried out by the heating
contractor
3
Furthermore, the quality of the heating water must be in accordance with ÖNORM H 5195 (current version) or VDI 2035

TABLE OF CONTENT
3
TABLE OF CONTENT
Page
page
INTRODUCTION...................................................2
TABLE OF CONTENT .......................................... 3
1SAFETY NOTES....................................4
1.1 Basic safety information.............................5
1.2 Installation ...................................................5
1.3 Operation and maintenance.......................5
1.3.1 General notes................................................5
1.3.2 Operation ......................................................5
1.3.3 Maintenance..................................................6
2WARNING NOTES ................................6
3FUELS....................................................7
3.1 Wood pellets................................................7
4SAFETY DEVICES ................................8
5SYSTEM.................................................9
5.1 System overview .........................................9
5.2 Boiler Overview.........................................10
5.2.1 pelletstar CONDENSATION with screw
discharge.....................................................10
5.2.2 pelletstar CONDENSATION with
integrated suction hopper............................11
5.2.3 pelletstar CONDENSATION with
integrated hopper (hand filling)....................12
6MODE OF OPERATION ......................13
6.1 Feeding system .........................................13
6.2 Versions conveyor systems.....................13
6.2.1 Version flexible screw system .....................13
6.2.2 Version suction system ...............................13
6.2.3 Version hopper for manual filling.................13
6.3 Feeding type..............................................13
6.4 Combustion air control.............................13
6.5 Boiler operation.........................................13
6.6 Commissioning .........................................14
6.7 Operating and impermissible
temperatures..............................................14
7OPERATING CONDITIONS ................15
8TEMPERATURE MANAGER ..............17
9T-CONTROL........................................21
9.1 Starting the system...................................21
9.2 Operation and handling............................22
9.3 Main menu .................................................22
9.4 Symbols explanation ................................23
9.5 Code –entry...............................................24
9.6 Switching the boiler on and off
(Chimney sweeping function) ..................25
9.7 Date and time.............................................26
9.8 Main menu values .....................................27
9.8.1 Adding / defining display values..................27
9.8.2 Delete values...............................................28
9.9 Fault messages and warnings .................29
9.10 Modules......................................................30
9.11 Module configuration................................31
9.12 Terms and definitions ...............................31
9.12.1 Boiler ...........................................................32
9.12.2 Buffer...........................................................38
9.12.3 Hot water tank .............................................40
9.12.4 Heating circuit..............................................42
9.12.5 Time mode...................................................47
9.12.6 Solar............................................................48
9.12.7 Hydraulic compensator................................50
9.12.8 Net pump.....................................................51
9.12.9 Zone valve...................................................52
9.12.10 External requirement ...................................54
9.12.11 Additional boiler...........................................57
9.13 System settings.........................................59
9.13.1 Network configuration..................................60
9.13.2 Modbus –settings .......................................61
9.13.3 Screensaver ................................................62
9.13.4 Remote........................................................62
9.13.5 Information overview....................................63
9.13.6 Sending E-mails ..........................................63
9.13.7 Mail Server settings.....................................65
9.13.8 E-Mail status report......................................65
9.13.9 Service special ............................................66
9.13.10 Cascade ......................................................66
10 FAULT REPORTS AND THEIR
FAULT REPORTS AND THEIR
CORRECTIONS...................................67
10.1 Not indicated faults ...................................75
11 MAINTENANCE SCHEDULE..............76
11.1 Weekly Inspection .....................................76
11.2 Monthly inspection, at least every 1000
operating hours .........................................76
11.3 Biannual inspection...................................79
11.4 Annually inspection (service,
notification)................................................80
11.5 As needed ..................................................81
12 EC/EU DECLARATION OF
CONFORMITY .....................................82
13 ACCORDING TO EU REGULATION
2015/1189.............................................83
14 INDEX DIRECTORY ............................84
15 ANNEX.................................................85
15.1Additional boiler (schematic
visualization)..............................................85
15.2 Solar module (schematic
representation) ..........................................87
16 NOTES .................................................93

1
Safety notes
4
1 SAFETY NOTES
◼Before commissioning, please read the documentation carefully and pay attention to the safety
instructions given in particular. Please consult this manual if anything is unclear.
◼Make sure that you understand the instructions contained in this manual and that you are sufficiently
informed regarding the way in which the biomass boiler system works. Should you have any queries
at any time, please do not hesitate to contact HERZ.
◼For safety reasons, the owner of the system must not make any changes to the construction or the
state of the system without consulting the manufacturer or his authorised representative.
◼Make sure that there is a sufficient supply of fresh air to the boiler room (please heed the relevant
national regulations).
◼All connections are to be checked before the commissioning of the system in order to make sure that
they are leak-tight. Check all screw connections for strength.
◼A portable fire-extinguisher of the prescribed size is to be kept by the boiler room. (Please heed the
relevant national regulations).
◼When opening the door to the combustion chamber, make sure that no flue gas or sparks escape.
Never leave the combustion chamber door open unattended. as toxic gases may escape.
◼Never heat the boiler using liquid fuels such as petrol or similar.
◼Carry out maintenance regularly (in accordance with the maintenance schedule) or use our
Customer Service department.
◼When carrying out maintenance on the system or opening the control unit, the power supply is to be
disconnected and the generally valid safety regulations are to be heeded.
◼In the boiler room, no fuels may be stored outside the system. It is also not permitted for objects
which are not required for the purpose of operating or carrying out maintenance on the system to be
kept in the boiler room.
◼When filling the fuel storage room using a pump truck, the boiler must always be switched off. (This
is stamped on the cover of the filling connection). If this instruction is not heeded, flammable and
toxic gases may get into the storage room!
◼The fuel storage room is to be protected against unauthorised access.
◼Always disconnect the power supply if you need to enter the fuel storage room.
◼Always use low-voltage lamps in the fuel storage room (these must be approved for this type of use
by the relevant manufacturer).
◼The system is only to be operated using the types of fuel prescribed.
◼Before the ash is transported further, it must be stored temporarily for at least 96 hours in order to let
it cool down. .
◼Should you have any queries, please call us on +43 3357 / 42840-840.
◼Initial commissioning must be carried out by the HERZ Customer Service department or an
authorised specialist (otherwise any warranty claim will not be applicable).
◼Ventilate fuel storage room for ~ 60 minutes before trespassing (Please refer to the respective
country regulations).
◼The boiler meets the requirements of the Association of Swiss Canton Fire Insurance Companies or
national fire safety regulations. The customer himself shall be responsible without exception for
ensuring that these regulations are complied with on site!

Safety notes
1
5
1.1 Basic safety information
Due to its functionally limited electrical and
mechanical characteristics with regard to usage,
operation and maintenance, if the equipment is
not able to work according to its appropriate use
or improper interference occurs, it may cause
serious health and material damage. It is therefore
conditional that the planning and implementation
of all installations, transportation, operation and
maintenance will be carried out and supervised by
responsible, qualified persons.
When operating electrical systems, certain parts
of those systems will always carry a hazardous
electrical voltage or be exposed to a mechanical
load. Only appropriately qualified personnel may
carry out work on the system. They must be
thoroughly familiar with the content of this and all
other manuals. In order for this system to function
safely and without any problems, transportation,
storage, operation and maintenance must be
carried out properly and carefully. Instructions and
information on the systems must also be heeded.
1.2 Installation
General safety notes
In order to ensure that the system will function
properly, the relevant standards and the
manufacturer’s installation instructions are to be
heeded during the installation of the system!
Documents from the manufacturer relating to the
heating devices and components used are
available from HERZ on request.
1.3 Operation and maintenance
1.3.1 General notes
Don´t open the boiler doors until
“HEATING OFF” is displayed,
otherwise a risk of deflagration
(explosion) is given.
In order for the system to be
operated and maintained safely,
it must be operated and
maintained properly by qualified
personnel while heeding the
warnings in this documentation
and the instructions on the
systems.
In unfavourable operating
conditions, the temperature of
boiler housing parts may exceed
80 °C.
If the door to the ash container is
opened during operation, the fuel
supply will be shut off and the
boiler will switch to the burnout
phase. Afterwards the boiler will
switch to the operating mode
“HEATING OFF”.
Ambient conditions
Operating temperature:
+10 to +40 °C
Warehouse-/ transport
temperature:
-20 to +70 °C
Humidity:
operation
5 to 85 %
storage
5 to 95 %
1.3.2 Operation
Covers which prevent contact
with hot or rotating parts or which
are required in order to direct the
flow of air correctly and thus
ensure the effective functioning
of the system must not be
opened during operation.
In the event of a fault or unusual
operating conditions such as the
emission of smoke or flames, the
system is to be switched off
immediately by operating the
emergency stop button. Notify
the HERZ Customer Service
department immediately.
◼If the boiler room door main switch is operated
or if a power failure occurs, the system will be
taken out of operation immediately. The
remaining quantity of residual fuel will burn
independently without giving off any toxic
gases, if the chimney draught is sufficiently.
Therefore the chimney must be designed and
produced in accordance with DIN 4705 or EN
13384 . When the boiler is switched on again,
the system has to be checked in order to make
sure that it is fully functional and a safe
operation of the whole system must be
guaranteed!
◼The noise generated by the machine during
operation does not present any danger to
health.
◼If the residual flue gas oxygen content drops
below the required minimum of 5 %, the fuel
supply will be stopped automatically and will
not be activated again until the residual oxygen
content has risen to more than 5 % (fault text:
MIN O2 [%] 5.0)

2
WARNING NOTES
6
1.3.3 Maintenance
Before starting to carry out any work on the
system, but especially before opening covers
protecting live parts, the system is to be properly
disconnected from the power supply. Besides the
main circuits, attention is also to be paid to any
existing additional or auxiliary circuits in the
process. The normal safety rules according to
ÖNORM are:
◼Disconnect all poles and all sides!
◼Ensure that the system cannot be
switched on again!
◼Check to ensure that no voltage is
connected!
◼Earth and short-circuit!
◼Cover adjacent live parts and locate
hazardous areas!
These above-mentioned
measures must not be reversed
until the system has been fully
installed and maintenance has
been completed.
Personal dust masks and gloves
must be worn when carrying out
maintenance in the combustion
chamber or the ash collector or
on flue gas-carrying parts and
when emptying the ash
container, etc.!
Extra-low-voltage lamps are to be
used when carrying out
maintenance in the fuel storage
room. Electrical equipment in the
fuel storage room must be
designed in accordance with
ÖNORM_EN_ISO_20023!
In order to prevent any maintenance errors, if
maintenance is not carried out properly, it is
recommended to be carried out regularly by
authorised personnel or by the HERZ Customer
Service department.
Spare parts must be obtained directly from the
manufacturer or a distribution partner.
2 WARNING NOTES
Risk of injury and damage to
property due to improper
handling of the system. Damage
to property is possible.
Caution –hot surface
Warning –against hand injuries.
No admittance without
authorisation.
However, adherence to guidelines for
transportation, installation, operation and
maintenance notices as well as technical data (in
the operating instructions, product documentation
and on the equipment itself) which are not
specifically highlighted, is also vital to avoid
breakdowns which may directly or indirectly cause
major personal or material damage.
General safety notes
For reasons of clarity and possible permutations,
this documentation does not contain all detailed
information and cannot take account of every
conceivable operating or maintenance scenario.
Should you require further information or
encounter specific problems, which are not
handled in detail in the documentation supplied,
you can obtain the required information from your
specialist dealer or direct from HERZ.
People (including children) who, because of their
physical, sensory or mental capabilities or
because of their lack of experience or knowledge,
are unable to use the equipment safely must not
use this equipment unless they are supervised or
instructed by a responsible person.

Fuels
3
7
3 FUELS
The HERZ pellets boiler should be operated with
the fuels and their properties which are described
in this chapter.
3.1 Wood pellets
Wood pellets for non-industrial use according to
ENplus, Swisspellet, DINplus resp. pellets
according to EN 17225-2 with following
specifications:
◼Property class A1
◼The maximum permissible fines content in
the fuel storage room must not exceed
8 % of the fuel volume (determined using
a perforated screen with holes 5 mm in
diameter)!-
◼Fines content at loading: < 1.0 m-%
◼Calorific value at as-delivered condition >
4,6 kWh/kg
◼Bulk density (BD) at as-delivered
condition > 600 kg/m³
◼Mechanical Strength (DU), at as-delivered
condition in m-%: DU 97,5 ≥ 97,5
◼Diameter 6 mm
Prevent the entering of debris such as stones
or metal particles into the system! Sand and
soil lead to higher level of ash and slagging
precipitation.
There may be a formation of slag according to the
fuel quality, which has to be removed by hand.
In the case of non-compliance, any warranty
or guarantee will be rendered null and void.
The burning of unsuitable fuels could lead to
uncontrolled combustion. Operational faults
and consequential damage are likely to occur.
If a different fuel is named explicitly on the order
respectively the order confirmation, the system
can be operated with the mentioned fuel.
Note: The system is set to the agreed fuel at the
commissioning. This setting (ID-fan speed, fuel,
flow and backflow, cycle times, etc.) should not be
changed when using constant fuel quality.

4
Safety devices
8
4 SAFETY DEVICES
The safety devices must be dimensioned and installed according to EN 12828 !
The safety valve in the boiler circulation serves as a final safety device against malfunctions of the
equipment.
All legal safety regulations must be adhered to on-site via the authorised specialist company.
Earthing or potential equalisation must be carried out on the whole heating system according to EN 60204-1
by an authorised specialist company.
1 Safety temperature limiter
If the boiler temperature exceeds 95 °C, the
equipment must be switched off for safety
reasons.
The safety temperature limiter (STL) will lock in
this case.
Possible causes may be:
◼Performance decrease in the boiler was
interrupted abruptly. This can occur due to
the switching off a pump or sudden
shutting of the heating circuit mixer.
◼The load pumps are being controlled by
the HERZ Control. The so-called excess
temperature flue gas would be
automatically activated by the HERZ
Control. This avoids higher boiler
temperatures.
◼The boiler is too large.
◼The fuel level is set too high.
◼Loss of power supply
◼Etc.
At First the cause of the failure must be found and
be corrected, afterwards the safety temperature
limiter can be unlocked.
The boiler temperature must be lower than 75
°C before unlocking.
Only then the problem can be acknowledged. For
this purpose, the cover of the STL is screwed off.
The STL can be unlocked by a light pressure with
a sharp object. After unscrewing the cover the
fault acknowledgement must be performed at the
switch box. The location of the STL is on the left
side next of the display.
2 Burn-back safety unit
The burn-back safety (BBP) unit prevents a burn-
back into the fuel storage room. It separates
additionally the combustion chamber and the fuel
storage room. The burn-back safety unit (or cell
wheel sluice) is conducted like a fire flap. It opens
only when fuel is fed to the boiler.
3 Safety valve
The safety valve automatically releases, when the
pressure or temperature exceeds preset limits.
The safety valve has to release at the maximum
allowable pressure (according to boiler plate).
4 Safety heat exchanger (depending on the
type)
The safety heat exchanger is a built in safety
device and has to be connected to a thermal
release valve and installed, according to applied
standards. The safety heat exchanger has to be
connected directly to a cold water pipe (pressure
≤ 3 bar)
5 Ash container safety device
The ash container door is connected contact-free
(inductive sensor) to the boiler.
Fuel storage room temperature monitoring
The fuel storage room temperature monitoring is
placed directly above the transport screw. There
is placed a temperature sensor which is setting to
the release temperature. If the storage room
temperature exceeds its preset limit, the boiler will
switch to the operate condition „HEATING OFF“
and displays a fault report. Additionally a fault
sensor output gets active. Conduct alerting in
accordance with national standards.

System
5
9
5 SYSTEM
5.1 System overview
Please consider that the installed room discharge and storage room filling system can be different to the
displayed system in example 1 and 2. More information can be provided by the company HERZ.
Example 1: Discharge via flexible screw
The room discharge with a flexible screw is an easy and energy saving
solution to empty the storage room in an efficient way.
1...Filling nozzles; 2...Impact mat; 3...Slide ramps; 4...Screw system in the storage room; 5...Flexible screw
Example 2: Discharge via suction system
The suction systems of HERZ are the ideal solution for longer distances from the storage room to the boiler.
Modular discharge screw in the storage room in combination with suction system: Optimum emptying of the
storage room and individual positioning of the boiler.
1…Filling nozzle; 2…Impact mat; 3…Slide ramps; 4…Auger discharge system; 5…… Suction- and reverse
air tube; 6…Integrated pellet hopper inclusive suction turbine

5
System
10
5.2 Boiler Overview
5.2.1 pelletstar CONDENSATION with screw discharge
1 Automatic tipping grate for complete cleaning
2 Lambda probe control automatic flue gas and combustion monitoring
3 Automatic heat exchanger cleaning
4 High heat resistant stainless steel combustion chamber
5 ID fan speed controlled
6 Pellet insertion
7 Back fire protection flap (BFP) –self-sealing tightly closing flap
8 Ashbox
9 Operating terminal (Central control unit)

System
5
11
5.2.2 pelletstar CONDENSATION with integrated suction hopper
1 Automatic tipping grate for complete cleaning
2 Lambda probe control automatic flue gas and combustion monitoring
3 Automatic heat exchanger cleaning
4 High heat resistant stainless steel combustion chamber
5 ID fan speed controlled
6 Pellet insertion
7 Back fire protection flap (BFP) –cell wheel
8 Ashbox
9 Integrated suction hopper with suction fitting

5
System
12
5.2.3 pelletstar CONDENSATION with integrated hopper (hand filling)
1 Automatic tipping grate for complete cleaning
2 Lambda probe control automatic flue gas and combustion monitoring
3 Automatic heat exchanger cleaning
4 High heat resistant stainless steel combustion chamber
5 ID fan speed controlled
6 Pellet insertion
7 Back fire protection flap (BFP) - cell wheel at integrated hooper
8 Ashbox
9 Integrated suction hopper with manual fitting

Mode of operation
6
13
6 MODE OF OPERATION
6.1 Feeding system
The fuel is fed from the fuel storage room by the
room discharge system to the burn back
protection device (BFP). Fuel passes the hopper
first, afterwards the back burn flap. The back burn
flap gets steered by a spring loaded servo motor.
If the servo motor operates current less, the back
burn flap will close independently. Next the fuel is
fed towards the burning chamber by the feeding
screw. The achieved fuel level is a crucial factor of
the boiler heat output and operating mode.
6.2 Versions conveyor systems
6.2.1 Version flexible screw system
In this version, the fuel supply with flexible
discharge screw from the storage room. Attached
to the boiler is an insertion screw, which conveys
the pellets obliquely upwards and feeds them by
means of a slide to the combustion. The backfire
protection device (BFP) is located on this feed
screw. This back-fire protection device is opened
by means of a spring return motor. At standstill or
power failure, this engine closes automatically.
The flap provides a fireproof separation between
the feed screw and the discharge screw.
The BFP also requires level monitoring.
The flexible room discharge of the boiler consists
of a stored auger including cover in the storage
room area and a flexible auger in the area of the
boiler room. As drive a standard gear motor is
used.
The insertion screw is roughly made up of the
following components:
➢Stoker screw motor
➢Fire-resistant device with spring return
motor
➢Stoker pipe
➢Feed screw temperature sensor (PT 1000)
6.2.2 Version suction system
In this execution, the fuel is supplied from the
storage room by means of suction probe or a rigid
screw or other sampling systems. This discharge
medium is located in the storage room. Outside
the storage room is sucked by vacuum. This
negative pressure is generated via a turbine,
which is mounted in the pellet boiler.
Before the suction process, the boiler is defined
"burned out" and carried out a rust cleaning. This
means that all the pellets on the grate are
completely burned and the resulting ash is
transported into the ash tray. During the suction
process, the pellets are conveyed via the suction
tube into a separator.
From the storage tank, the pellets are first
transported via the chute with a screw conveyor
including cell wheel. Next the fuel is fed towards
the burning chamber by the feeding screw. These
are then directed to the combustion chamber via a
drop level.
The discharge of the fuel from the fuel storage
room via a screw conveyor. The room extractor is
driven by a gearmotor at the boiler end of the
auger. The auger is as far as possible equipped
with a spiral auger to prevent congestion.
6.2.3 Version hopper for manual filling
In this version, the pellets are manually filled in a
storage hopper. From the storage tank, the pellets
are first transported via the chute with a screw
conveyor including cell wheel. Next the fuel is fed
towards the burning chamber by the feeding
screw. These are then directed to the combustion
chamber via a drop level.
6.3 Feeding type
The operation of the boiler is based on a pulse-
no-pulse ratio, which controls the feeding system.
All the values are to be set via the menu “Fuel
values” (only available in the service area). These
feed values are corrected by the combustion
control system.
6.4 Combustion air control
The supplied combustion air is differentiated
between primary and secondary air. The primary
air is initiated directly into the embers. The
secondary air gets used to actuate the developed
flame to a completely. The air supply is piped via
vents on the burner side (underneath side cover).
The flue gas ventilator is a suction fan and this is
located at the back of the boiler. It generates low
pressure in the boiler. The secondary- and
primary air get sucked out due low pressure.
The ID-fan is time-controlled by the variable-
speed electronic control. The ID-fan speed is
controlled according to the boiler temperature and
rectified by the lambda control.
6.5 Boiler operation
The boiler starts up automatically with its built-in
automatic ignition, when heat is required.
The heat requirement can be controlled by the
weather or by a remote sensor (optional),
depending on any heating circuit. A room
thermometer can also be used to generate an
external requirement. The boiler can also be
started up by the requirement of a hot water tank.
The boiler output can be controlled by set up
values and adjusted to local conditions.
Too high boiler temperatures are not permissible.

6
Mode of operation
14
Expansion cracks at insulating plates, respectively
burning chamber stones, don´t affect their
capacities and don´t represent warranty claim.
6.6 Commissioning
The commissioning must be carried out by HERZ
factory customer service or an authorised
specialist.
A pressure measurement is conducted
additionally after boiler has been operated with
the actual fuel for minimum 1 hour.
The result of the pressure measurement
represents a characterisation of the draught
during normal operation and shows, if the required
draught has been reached. If a deviation occurs,
the existing chimney has not been dimensioned
correctly or dimensioning underlying installations
have not been carried out correctly (e.g.: faulty
connections, false air inflow, too long connection
pipe,...). Then the chimney system must be
checked by a specialist.
During initial operation and commissioning the
system controls and safety devices must be
checked and the handling of the boiler as well as
the system maintenance schedule must be
explained to the operator.
The hydraulic balancing of the equipment (pipe
installation) must be carried out by an authorised
specialist company (installer). The installer is also
obliged (according to Draft documentation for all
the equipment (according to ÖNORM EN 12170),
which must be kept in the boiler room.
6.7 Operating and impermissible
temperatures
Boiler temperature
The HERZ pelletstar boiler operates at a boiler
temperature between 25 °C up to 90 °C. The back
flow temperature may also be lower than the
permissible value at correct boiler operating
temperature.
Back flow temperature
The back flow temperature is always lower than
the boiler temperature. The raising of the back
flow temperature can be realized by a working
flow temperature booster.
Too high boiler temperatures
The HERZ pelletstar boiler can be operated with a
maximum boiler temperature up to 90 °C. If the
decrease of performance drops suddenly (mixers
shut-off, hot water tank load pump switches off)
the boiler´s saved heat energy can overheat the
boiler.
The pelletstar boiler has two or three different pre-
installed safety devices to prohibit a further
temperature increase:
◼Overheat temperature (higher than 92 °C
boiler temperature)
At this temperature the connected consumer
pumps get switched on in order to conduct
overheat (consumer pump connection to the
HERZ controls is required). Therefore, the
consumers will set on their maximum value.
Consumer pump connection to the HERZ
controls is required. If the consumer pumps
aren´t connected to the HERZ controls, a
higher probability of overheating, resulting in
failure, is given.
◼Safety temperature limiter –STL (over 95°C
boiler temperature)
At this temperature the boiler gets switched
off. The safety temperature limiter locks itself
and the boiler operation. A fault report gets
indicated, the boiler gets switched off.
◼Thermal valve for security heat exchanger
(depending on the type)
The thermal valve must be connected to the
built-in safety heat exchanger, according to
applied standards.
Flue gas temperature
The flue gas temperature depends on the boiler
operation conditions, the fuel, the ventilator setting
and the boiler type.
Observe:
The chimney must be insensitive to moisture and
calculated and dimensioned according to DIN
18160 or EN 13384. HERZ does not carry out
chimney calculations. The chimney calculation
must be calculated by authorised personnel. A
miscalculated or under dimensioned chimney may
lead to a malfunction of the system.

Operating conditions
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15
7 OPERATING CONDITIONS
Heating off
During this phase the boiler is switched off, i.e. the
burner is blocked.
Ready
The boiler- respectively the buffer temperature is
sufficiently high to provide the required heat load,
or the boiler temperature has reached the switch
off temperature.
Ignition preparation
During this phase the grate gets cleaned and the
lambda probe gets pre-heated.
Pre-aeration
During the pre-aeration phase the burning
chamber and the chimney get purged with fresh
air.
Cold start
If the boiler room temperature is lower than the
identified boiler room ignition temperature (150
°C), the boiler performs a cold start and fuel is fed
to the burning chamber. Materials are pushed in
at intervals. At the same time the fuel gets ignited
by the ignition fan. An ignition monitoring is
conducted during this phase. Successful ignition
is detected when there is a steady increase in the
combustion chamber or exhaust gas temperature
or at the latest when the combustion chamber
ignition temperature is reached.
Thereafter, the system changes over to the scorch
phase, where at the same time the final ignition
fan phase is carried out. During the final ignition
fan phase the ventilator of the ignition fans runs
for a minute longer in order to cool down the
heating element.
If ignition wasn´t possible prior the maximum
ignition period, the boiler will switch off and the
fault “IGNITION” will appear in the fault list.
Scorch phase
During the scorch phase the boiler control tries to
achieve an even fire bed. The length of the scorch
phase can be set in the fuel value settings (only
available in the service area). Pay attention to the
higher oxygen content at the combustion. During
the scorch phase the boiler control tries to achieve
an even fire bed.
Start up phase
During the start up phase the boiler operates at
nominal heat output. If the boiler set temperature
is reached, the boiler will switch to the regulation
phase.
Regulation phase
During the regulation phase the boiler is
modulated between nominal load and partial load.
If boiler oversupplies heat, i.e. if the boiler target
temperature + control hysteresis gets exceeded,
the boiler will switch to the operating condition
„ready”.
Burn out phase
If the boiler will be switched off the remaining
quantity of residual fuel will burn independently.
Pay attention to the burn out phase time setup, if
chosen too short, fuel will not be burned
accordingly.
Burner cleaning
During the burner cleaning phase ash gets
removed off the grate. The boiler switches to the
burn out phase and remaining fuel gets burned
out.
Afterwards the grate gets cleaned and the boiler s
witches to normal operation. Afterwards the grate
gets cleaned and the boiler switches to normal
operation. The burner cleaning interval is
calculated by the feeding screw operating time.
This is set up with the parameter “ash discharge
interval” in the service area. So if the grate should
cleaning frequently you have to reduce the
parameter.
Please note that during burner
cleaning phase no respectively
only reduced heat output is
available. Consider these
cleaning intervals at your
planning.
Heat exchanger cleaning
The Heat exchanger gets cleaned automatically.
The cleaning interval and duration is set up in the
service area with the parameter “heat exchanger
cleaning interval“ respectively „heat exchanger
cleaning duration“.
Boiler output control
The output control is controlled within the boiler
target temperature and the control end phase.
The control end phase is the boiler target
temperature + control hysteresis. If the regulation
end is reached, the boiler will switch to the burn
out phase.
Flue gas temperature control
If the maximum flue gas temperature is exceeded,
the boiler output will be reduced. If the actual flue
gas temperature is lower than the maximum flue
gas temperature, the boiler will switch to normal
output control.

7
Operating conditions
16
Flame monitoring (burning chamber
temperature)
If the burning chamber temperature fluctuates
greatly during operation, the boiler will switch off.
Freezing protection
If the freezing protection operates, the back flow
bypass pump will switch on only if the boiler is in
operating mode “HEATING OFF” or “BURNER
STOP”. Otherwise (freezing protection disabled)
the boiler will start up and heat up to minimum
boiler temperature.
Lambda control
The amount of fuel and the rotation speed of the
ID-fan are controlled by the lambda control. The
control is able to detect marginal deviations of the
fuel quality and induces a combustion
improvement.

Temperature manager
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17
8 TEMPERATURE MANAGER
The heat demand of the individual modules (boiler, hot water tank, heating circuit, solar, etc.) is controlled by
the temperature manager. The below-mentioned scheme explains the functionality of the temperature
manager. From the individual modules the MUST-temperature is determined and to that an adjustable temp.
increase is added. The highest temperature of all consumers is transferred to the buffer which is the buffer-
top-MUST-temperature. In the buffer there are now the buffer-top-MUST and an adjustable buffer-bottom-
MUST-temperature. To the higher temperature of these an increase and a difference (not always!) are
added. This temperature is the boiler-MUST-temperature. In addition, there is the minimum requirement in
the boiler setting. This is the minimal boiler must temperature during operation of the boiler. For example: If a
required temperature by the consumer is lower than the minimum requirement, the boiler automatically
selects the minimum requirement temperature.
The boiler-END-temperature results from the boiler-MUST-temperature and the adjustable control hysteresis.
The boiler switches to the "Ready"-mode if the buffer-bottom-MUST-temperature is reached before the boiler
END-temperature and the buffer-top-temperature is higher than the highest request to the buffer.
The boiler max. temperature is 90 °C. Increases the calculated boiler-MUST-temperature + control
hysteresis above the boiler max. temperature the set control hysteresis is subtracted from the boiler max.
temperature and the boiler-MUST-temperature is corrected downwards. Then the boiler reaches the actual
MUST-temperature during the control phase.
Figure 8. 1: Temperature manager (simplified representation - example)

8
Temperature manager
18
If the required buffer-top-temperature (required temperature) is higher than the sum of buffer-bottom-MUST-
temperature and the set difference, then the required boiler temperature is the result of the required buffer-
top-temperature (required temperature) + the adjusted temp. increase. Caution: Consider the set minimum
requirement.
Fig. 8.2: Example temperature manager with buffer and without difference
If the required buffer-top-temperature (required temperature) is lower than the buffer-bottom-MUST-
temperature than the required boiler temperature is the result of the required buffer-bottom-temperature +
the adjusted temp. increase + the adjusted difference (see fig. 8.2). Caution: Consider the set minimum
requirement.
Fig 8.3: Example temperature manager with buffer and difference

Temperature manager
8
19
If there is no buffer in the system, then the MUST-temperature from the individual modules is determined and
to that an adjustable temp. increase is added. The highest of these temperatures is the boiler-MUST-
temperature. To this an adjustable hysteresis is added and the result is the boiler-END-temperature (see fig.
8.4). Caution: Consider the set minimum requirement.
Fig 8.4: Example temperature manager when operation without buffer
If a time mode is applied directly on the buffer, then the required buffer-top-temperature is set directly in the
time mode module. Now it must be distinguished again if the buffer-top-temperature is higher than the
adjusted buffer-bottom-MUST-temperature. In this case the required boiler temperature is the result of the
required buffer-bottom-MUST-temperature + the adjusted temp. increase + the adjusted difference (see fig.
8.5). If this is not the case, the required boiler temperature is the result of the required temperature + the
adjusted temp. increase (see 8.6). Caution: Consider the set minimum requirement.
Fig 8.5: Example temperature manager when time mode with difference

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Temperature manager
20
Fig 8.6: Example temperature manager when time mode without difference