Herz pelletfire 20/20 User manual

OPERATING INSTRUCTIONS
Log wood & pellet heating system
pelletfire
20-40

Introduction
2 Betriebsanleitung_pelletfire_20-40_T-CONTROL_2_eng_V1.0
INTRODUCTION
Dear Customer!
Your heating equipment is powered using HERZ pelletfire 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 there is no return flow
temperature boost or it is not working properly, if commissioning
1
is not carried out by specialist personnel
authorised by HERZ, in the case of operation without a buffer storage tank 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 according to
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.
Guarantee work does not affect any extension of the general term of guarantee. A guarantee claim does not
delay the due date of our accounts. We only offer a guarantee if all our accounts have been paid for the
product delivered.
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 01/2022
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
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 Log wood....................................................7
3.2 Wood pellets...............................................7
3.3 Suitable fuels..............................................7
3.4 Not suitable fuels........................................8
3.5 Fuel storage room ......................................8
3.5.1 Filling ...........................................................8
4HANDLING OF THE HEATING
SYSTEM ................................................9
4.1 Sealing the boiler........................................9
4.2 Operation with low performance
decrease .....................................................9
4.3 Overheating of the boiler-STL....................9
4.4 Sweating of the boiler ................................9
4.5 Decommissioning.......................................9
5BOILER OPERATION .........................10
5.3 Cold system start up................................11
5.5 Feeding system (pellet)............................11
5.6 Feeding type.............................................11
5.7 Combustion air control ............................11
5.8 Boiler operation........................................11
5.9 Commissioning ........................................12
6SYSTEM ..............................................13
6.1 Section pelletfire ......................................13
6.2 Section firestar .........................................14
6.3 Re-heating ................................................15
7OPERATING CONDITIONS ................15
7.1 Boiler operation with log wood................15
7.2 Boiler operation with pellet......................17
8TEMPERATURE MANAGER ..............19
9MENU NAVIGATION AND
ADJUSTMENT VALUES .....................23
9.1 Lambda control ........................................23
9.1.1 Display Controls.........................................23
9.2 T-CONTROL..............................................24
9.3 Starting the system ..................................24
9.3.1 Operation and handling ..............................25
9.4 Main menu ................................................25
9.5 Symbols explanation................................26
9.6 Code –entry .............................................27
9.7 Switching the boiler on and off
(chimney sweeping function)...................28
9.8 Date and time............................................29
9.9 Main menu values.....................................30
9.9.1 Adding / defining display values..................30
9.9.2 Delete values.............................................31
9.10 Fault messages and warnings................. 32
9.11 Module...................................................... 33
9.12 Module configuration............................... 34
9.13 Terms and definitions.............................. 34
9.13.1 Boiler......................................................... 35
9.13.2 Buffer......................................................... 41
9.13.3 Hot water tank............................................43
9.13.4 Heating circuit............................................ 45
9.13.5 Time mode.................................................50
9.13.6 Solar.......................................................... 51
9.13.7 Hydraulic compensator ..............................53
9.13.8 Net pump................................................... 54
9.13.9 Zone valve................................................. 55
9.13.10 External requirement..................................57
9.13.11 Additional boiler.........................................60
9.14 System settings ....................................... 62
9.14.1 Network configuration ................................63
9.14.2 Modbus –settings...................................... 64
9.14.3 Screensaver .............................................. 65
9.14.4 Remote......................................................65
9.14.5 Information overview.................................. 66
9.14.6 Sending E-mails......................................... 66
9.14.7 Mail Server settings ...................................68
9.14.8 E-Mail status report.................................... 68
9.14.9 Service special........................................... 69
9.14.10 Cascade....................................................69
9.14.11 Fault reports and their corrections.............. 70
9.15 Not indicated faults.................................. 79
10 MAINTENANCE SCHEDULE
(CUSTOMER INSPECTION)............... 80
10.1 Weekly Inspection.................................... 80
10.2 Monthly inspection, at least every 1000
operating hours ....................................... 81
10.3 Annually inspection................................. 84
10.4 As needed ................................................ 85
11 EU DECLARATION OF
CONFORMITY.....................................86
12 INFORMATION ACCORDING EC-
REGULATION 2015/1189...................87
13 CORRECT DISPOSAL OF THIS
PRODUCT...........................................88
14 INDEX DIRECTORY............................89
15 ANNEX................................................ 90
15.1 Additional boiler module ......................... 90
15.2 Solar module............................................ 92
16 NOTES ................................................98

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 bunker 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 bunker is to be protected against unauthorised access.
◼Always disconnect the power supply if you need to enter the fuel bunker.
◼Always use low-voltage lamps in the 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.
◼Initial commissioning must be carried out by the 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 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 temp.:
-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 generated system noise during operation
does not present any danger to the operator´s
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 ÖN
M 7137!
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 note
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 pelletfire boiler should be operated
with the fuels and their properties which are
described in this chapter.
3.1 Log wood
The HERZ –pelletfire is suitable for burning logs
to operate central heating systems for closed hot
water installations. Smaller split logs enable
higher boiler performance than whole ones. We
recommend triangular firewood with side lengths
of 50 cm and edge lengths of 8 cm. Too coarse or
too long firewood may lead to reduced
performance and hollow fire. The heat value of the
wood is primarily dependent on its moisture
content. The heat value decreases with increased
moisture. The combustion of wood with high
moisture content also causes a decrease in the
degree of efficiency of the boiler.
Wood should therefore be stored for at least two
years in a dry, ventilated place. Oak needs to be
stored for about a year longer. Dry bark displays a
heat value similar to wood but there is more likely
to be increased formation of ash.
The burning of unsuitable fuels could lead to
uncontrolled combustion. The guarantee
becomes invalid! Operational faults and
consequential damage are likely to occur.
Possible consequential damage:
◼Damage to the thermodynamic combustion
chamber, the lambda probe, the flue gas
probe due to aggressive residues in the
boiler
◼Sooting or corrosion in the filling area due to
condensation as a result of using fuel that is
too moist.
◼The escape of flue gas from the airflow
apertures through uncontrolled combustion
(deflagrations).
Combustion time at nominal load:
Combustion time in hours
Type
FS 18
FS 20
FS 30
FS 40
Softwood
5
6,5
6
3,5
Hardwood
6
8
7
4,5
Wood
chips
3
4
3,5
2,5
3.2 Wood pellets
Wood pellets for non-industrial use according to
ENplus, Swisspellet, DINplus resp. pellets
according to EN 17225 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), EN 15210-1 at
as-delivered condition in m-%: DU 97,5 ≥
97,5
◼Diameter 6 mm
The nominal power and the emission values can
be guaranteed up to a maximum water content of
25 % and a minimum calorific value of 3,5 kWh/kg
of the permissible fuel.
From a water content of about 25 % and a
calorific value < 3,5 kWh/kg a reduced output is
expected.
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.
3.3 Suitable fuels
The firewood must be air dried, that is, dried at
least one year with water content below 20 %
preferable half-meter logs with an average
diameter of 10 cm. If the cleavage planes of the

3
Fuels
8
log wood are much larger, the log wood should be
thinner, in extreme cases 20 to 5 cm.
Small sized material may be burned only as
admixture. From the smaller material may be
added less. Wood briquettes 6-10 cm in diameter
according to EN 17225-3.
Only one oversized log each boiler filling
To split a root stock to such thin pieces is very
hard work. Per boiler filling maximum one large
root stock piece are burned up in the stack.
Type of
wood
Calorific values (by wood
moisture 25%) in kWh/stere
Beech
1890
Oak
1930
Pine
1520
Spruce
1330
We recommend to use beech
wood. Do not mix different types
of wood. The use of one type of
wood promotes a consistent burn-
off and reduces burning
disturbance. However, if it cannot
be avoided to use different types
of wood, the boiler must be filled
in layers (softwood below,
hardwood above).
3.4 Not suitable fuels
When burning wet fuel with more than 30 % water
content, condensation water formation and
corrosion on the walls of the filling chamber occur.
Furthermore, should not be burned:
Garbage, plastics, paper and cardboard (only for
starting the fire), sanding dust, wood shavings,
wood chips smaller than thumb-size, coal and
coke, the respective Clean Air Act (state law)
usually prohibited fuels such as old railroad ties,
plastics, particle board, impregnated wood.
3.5 Fuel storage room
The storage must conform to
ÖNORM_EN_ISO_20023:
◼Filling pipe maximum 30 m
◼Sloping floor 35-40°
◼A rubber mate opposite the blow-in supports
◼Protection against water and moisture
◼Dust proof
◼Fire protection category F 90
◼Filling nozzle near outside wall
◼Easy to access
◼No electrical installation in the storage room
◼Wall thickness minimum 12 cm on both sides
plaster or 10 cm cement
3.5.1 Filling
At least 1 hour before filling of the
storage the boiler must be in the
operating condition „Heating OFF“.
After filling the corresponding lock
cover must be attached

Handling of the heating system
4
9
4 HANDLING OF THE
HEATING SYSTEM
4.1 Sealing the boiler
It is imperative that all doors are closed during
operation so that no leak air can disrupt the
combustion process. If this is not observed then
damage to the boiler may result.
4.2 Operation with low
performance decrease
Should fuel be burned in the transition period
(spring or autumn) it is vital to ensure that for low
decreased performance (less than 50%) the filling
shaft is not completely put on. Decreased
performance of less than 50 % means the boiler
and the chimney may become clogged with soot.
It is also possible that smoke may develop in the
chimney. The pelletfire boiler should there for
basically be operated equipped with a
correctly dimensioned buffer (according to EN
303-5). Recommended dimensions are listed in
the document “installation instructions".
4.3 Overheating of the boiler-STL
Should the boiler temperature exceed maximum
boiler temperature, the safety temperature limiter
switches the controls off. After the equipment has
cooled off under about 75°C, the Safety
Temperature Limiter (STL) should be tripped by
unscrewing the covering cap (press the button).
Afterwards screw up the covering cap again.
Before re-starting the cause of the overheating
should be identified and corrected.
Thermal valve for security heat exchanger
If the boiler overheats then the “thermal safety
device” opens automatically (at 95°C) via a sensor
and cold water flows through the heat exchanger.
The boiler water is thereby cooled off and
dangerous operating conditions are prevented.
The water heated up in the heat exchanger must
be able to run away freely (directly into the waste
water channel). After the boiler water has cooled
off about 90 °C the "thermal safety device”
automatically interrupts the cold water feed. After
cooling off the equipment pressure and/or water
level of the equipment is to be controlled and if
necessary the missing amount of water topped
up. According to DIN 4751 sheet 2 the operator is
obliged to regulate the functioning of the “thermal
safety device” and the heat exchanger belonging
to it at least once a month by activating the test
button. Furthermore this safety instruction is to be
monitored once a year by the manufacturing
company or another competent organisation.
Attention:
If it is a inoperable combination of the “thermal
safety device” and heat exchanger, the set-up of
the equipment is prohibited!!
4.4 Sweating of the boiler
During long-term operation it should be
guaranteed that the return flow temperature does
not fall below 65 °C. For this reason a return flow
temperature bypass is obligatory.
Attention:
Corrosion damages which are caused by too low
return flow temperatures do not come under the
guarantee or warranty.
4.5 Decommissioning
The main switch should not be turned “OFF”
during the burn-off only after complete burn-off.
(Status: Heating off)

5
Boiler operation
10
5 BOILER OPERATION
The heating operation is performed with log wood
or pellet. Due to the separate combustion
chambers there can be flexible switched between
log wood and pellets operation.
5.1 Preparation for heating up
with log wood
If possible, store enough fuel for two or three
combustion processes near the boiler room.
Prepare firewood
The firewood must correspond to size
(circumference 8- 10 cm) and dimensions to the
size of the boiler. Firewood without bark burns
better.
5.2 Heating up
Warning: Risk of system damage
due to improper maintenance!
Wrong position or lack of firebricks
inside the boiler can lead to
damage or destruction of the
boiler.
◼Before heating up the boiler,
check the position of the
firebricks.
Warning: Risk of system damage
due to improper maintenance!
Excessive fuel feeding can cause
overheating and damage to the
boiler.
◼Adapt the amount of fuel to
the energy absorption
capacity of the heating
system.
Crucial for the clean burn-off in the
boiler are the correct operation of
the boiler as well as a sufficient
feed pressure of the exhaust
system.
When heating up with log wood
there may occur a greater smoke
production at the chimney.
In the following a possibility for the heating up of
the boiler is described. Depending on the ambient
conditions (draft, exhaust system, wood, and so
on) other heating up processes may be better.
Get conversant with the boiler and find out the
best handling to use. Test the best opportunity for
heating up the boiler.
Please note always the safety notes!
◼Switch on the main switch [2] and regulator
(→On/Off –button, page). The regulator
displays status 1.
1 … Cable bushing
2 ... Main switch
3 … Electric supply
◼After the casing door is opened the “burning”
phase (Status: 2) starts automatically.
If it is not desired or necessary to
heat up the boiler, this process
can be interrupted with a long
press of the On/Off button.
◼To form a good flame, it is recommended that
the lower third of the filling shaft be filled with
small pieces of wood.
◼After that normally chopped wood (size
around 8 cm) can be used for filling.
◼Then close filling door and open the firing
door (4) and fire up with an oil ignition, wood
shavings or cardboard.
◼When the flue gas temperature is 120°C,
close all doors.
By sufficient feed pressure a fire bed (chimney
flue) is built up and the wood in the filling room is
burning from bottom to top.

Boiler operation
5
11
Too short and thick wood logs
lead to an uneven burning
behaviour. Too short and thin
wood reduces the burning time.
→Only use wood logs according
to specification
It is imperative that all doors are
closed during operation so that no
leak air can disrupt the
combustion process.
The heating-up time can change
due to the cleaning condition of
the boiler, the local conditions, the
used fuels and the weather
changes (low pressure in the
exhaust system).
The boiler operates according to the principle of
the lower burn-up. The control device controls the
boiler automatically and completely.
5.3 Cold system start up
After a long period of not being used, you should
take particular note of the following points when
starting up the system:
◼Where the equipment has cooled down, the
boiler requires a proportionate amount of
time to reach temperature if all heat
consumers are switched on during the
heating up process. Therefore, firstly put only
one small heating circuit into operation and
switch the other heating circuits only on when
the boiler has reached its operating
temperature. The first start-up should only be
carried out by HERZ factory customer service
or persons authorised as such.
5.4 Boiler in combination mode
(automatic mode)
If the buffer or heating circuits require heat after
burning of all logs, the operation is automatically
continued with pellets.
In combination mode the boiler works as a
automatically fed system. After power up the
boiler is ready for operational.
The start of the combustion occurs automatically
after heat it requested or at a defined starting
point. When at this time the boiler is filled with log
wood, the ignition of the log wood starts with the
pellet burner. After burning off of the log wood and
if there is a heat request, the boiler starts
automatically in pellets mode.
5.5 Feeding system (pellet)
The fuel is fed from the fuel storage room by the
room discharge system to the burn back
protection device. 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. These are then directed to the combustion
chamber via a drop level. The achieved fuel level
is a crucial factor of the boiler heat output and
operating mode.
5.6 Feeding type
The operation of the pelletfire 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.
5.7 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.
5.8 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 a
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.
The boiler control prevents too low boiler
temperatures to avoid effect on the durability of
the system. Too high boiler temperatures are not
permissible.
Expansion cracks at insulating plates, respectively
burning chamber stones, don´t affect their
capacities and don´t represent warranty claim.

5
Boiler operation
12
5.9 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 > 1 hour and a flow temperature
of 70-85 °C.
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,...) and the boiler does not operate properly.
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´s duty
(according to ÖNORM 12170) is to create
documentation of the heating system. The
documentation has to be retained in the boiler
room.

System
6
13
6 SYSTEM
6.1 Section pelletfire
1. T-Control (central control unit)
2. Efficient heat insulation for the lowest radiation losses
3. High heat resistant stainless steel combustion chamber
4. Automatic ignition
5. Automatic tipping grate at the pellet burner for complete cleaning
6. Combustion ash box from easy access from the front
7. ID-fan speed controlled and monitored for the highest operating safety
8. Lambda probe control automatic flue gas and combustion monitoring
9. Pipe heat exchanger with turbulators and automatic cleaning
10. Certified back fire protection flap (BFP)
1
2
3
4
5
6
7
8
9
10

6
System
14
6.2 Section firestar
Caption:
1 ... T-CONTROL
8 … Inspection glass
15 ... Ventilator
2 … Filling door
9 ... Ash container
16 ... Heat Exchanger Tubes
3 … Primary air feed
10 … Secondary air aperture
17 … Cleaning brush
4 … firing door
11 … Primary air aperture
18 … Poking stick for burner plate
5 … Burner plate
12 ... Cleaning lid
19 … Poking stick for primary air feeds
6 … Secondary air aperture
13 … Turbulators
7 ... Ash door
14 ... Lambda fuel
1
10
11
12
14
15
2
3
4
5
6
7
8
9
13
16
17
18
19

Operating conditions
7
15
6.3 Re-heating
Depending on the wood type and quality the
burning time of a filled boiler by nominal capacity
is about three to eight hours.
By intermediate opening of the
front door or the filling room door
the combustion is disturbed.
These can lead to a poorer
combustion behaviour and
excessive escape of flue gas.
➔Filling should burn down
completely
To refill fuel or to check the fill level:
◼Open the casing door –the ID-
fan going at full speed, so that
the flue gas is sucked out via
the smoke flue channel by
opening the filling door (2)
◼Slowly open the filling door (2)
◼Put in the fuel
◼Close the filling door and
casing door
◼A quick covering of the glow
with wood logs reduces the
leakage of hot gases from the
filling room. Refill only as
much fuel as for the energy
absorption capacity of the
system is permitted.
◼The lower buffer temperature
should be mind. If the buffer is
already loaded (lower buffer
temperature over 40°C),
please avoid a reloading of
fuel. By too slight heat
consumption the risk of tar
formation and overheating of
the boiler is existed.
The HERZ-firestar special boiler is characterising
by long combustion duration. It does not have to
be re-filled with fuel at frequent intervals. It is
recommended that the filling shaft only be filled
according to the heating requirement, so that
frequent opening of the filling door does not have
a negative effect on combustion.
7 OPERATING
CONDITIONS
7.1 Boiler operation with log
wood
HEATING OFF
During this phase the boiler is switched off, i.e. the
burner is blocked.
Scorch phase
In the BURNING PHASE condition wait to see if
the logs catch fire in the combustion chamber.
During 30 minutes an adequate flue temperature
(HEATING UP FROM MIN) is adjusted so that it
can be switched on into the HIGH RUNNING
PHASE condition. If this flue gas temperature is
not set, it switches into the HEATING OFF
condition and a corresponding fault is declared.
In this condition it is possible to switch manually
into the UNIT OFF condition.
Start up phase
In the RUN UP PHASE condition, after lightings
the logs, it tries to stabilise the combustion and
achieve the minimum boiler temperature. The
optional combustion control (lambda control) is
already activated at this time. When reaching 65
°C the boiler temperature (set out in the program)
it is switched to the control phase. If the flue gas
temperature decreases in this phase (below FLUE
GAS MIN TEMP.), it switches into the RESTART.
Control phase
The CONTROL PHASE condition carries out
actual boiler control, which splits into an output
and combustion control (OPTIONAL). If the boiler
temperature increases in this phase above the
maximum boiler temperature (BOILER MAX), it
switches into the READY condition. If the flue gas
temperature decreases in this phase below the
allowed (FLUE GAS MIN TEMP.) it switches into
the RESTART condition.
Ready
The maximal boiler temperature (BOILER MAX
(P02)) has been reached due to too low heat
capturing. Therefore, the boiler has been switched
off. The boiler starts up again if the boiler
temperature falls 3°C below BOILER MAX.
Restart
The NEW START-UP condition tries to re-
stabilise the combustion within a time limit
(adjustable via MAXIMUM RE-START). It will
always be activated if the flue gas temperature is
too low. If there is a stable combustion again, it

7
Operating conditions
16
switches immediately into the CONTROL PHASE.
If a sufficient flue temperature is not achieved
after a specified time (below FLUE GAS MIN
TEMP), the boiler switches off by switching in the
HEATING OFF condition.
Re-heating
The RE-HEATING condition is used for safe
operation for re-heating. If the customer re-heats
a larger amount of logs in operation, then this
operation is activated. The boiler then remains in
this condition for the time set. If the boiler
temperature in the meantime increase above the
maximum boiler temperature, the boiler will be
switched off. After the set time is switched at
sufficient flue gas temperature in the state
CONTROL PHASE. If the flue gas temperature is
too low (below FLUE GAS MIN TEMP.) it is
stopped and an error is displayed. This function
may only be activated by long pressing the
On/Off-switch in the STATUS MENU, if the unit is
in HIGH RUNNING or CONTROL PHASE.
Chimney sweeper
The CHIMNEY SWEEPER MODE provides a test
mode for the chimney sweeper. The boiler is
operated steadily at nominal output and all
consumer values are set to its maximum during
the chimney sweeper carries out its
measurements. The boiler runs high normally and
the chimney sweeper function is only activated
instead of the CONTROL PHASE. This condition
is left when deactivation occurs or when the boiler
maximum temperature is exceeded or when the
maximum chimney sweeping time is exceeded
(45min).
LAMBDA CALIBRATION (code protected)
By activating the parameter LAMBDA
CALIBRATION in the parameter menu, the
calibration starts (only in condition UNIT OFF
activatable). The lambda probe is calibrated at the
factory.
Flue gas temperature control
The flue gas temperature control begins if the
HEAT UP FROM MIN(P06) is exceeded. The
target temperature modulates between the set
values FLUE GAS NOMINAL LOAD and FLUE
GAS PART LOAD. In the high running phase as
well as when re-heating, it will be controlled at an
increased flue temperature (FLUE NL + 15). The
15 °C are a setpoint specification. The actual
temperature deviance may be higher.
Lambda control
The primary and secondary air is controlled via
the lambda sensor. The control is able to detect
marginal deviations of the fuel quality and induces
a combustion improvement.
Control curve
Flue gas –must
temperature
FLUEGAS NL
FLUEGAS TL
HEAT UP FROM MIN
65 °C
BOILER MUST
BOILER MAX
FLUEGAS NL +15 °C

Operating conditions
7
17
7.2 Boiler operation with pellet
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. This
serves to achieve the desired even fire bed more
quickly. This phase should not be set for longer
than 5 minutes.
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 control phase the boiler modulates
between nominal load and part load. When the
partial load stage generates too much energy, i.e.
the target boiler temperature + regulation
hysteresis are exceeded and are then changed to
the ready condition.
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.
The cleaning interval and duration is set up in the
service area with the parameter “heat exchanger
cleaning interval“ respectively „heat exchanger
cleaning duration“. This can be set via the
“Cleaning interval” parameter in the service area,
i.e. in order to achieve more frequent cleaning of
the combustion chamber the parameter simply
has to be shortened.
Heat exchanger cleaning
Heat exchanger cleaning serves to increase the
degree of efficiency. The Heat exchanger gets
cleaned automatically and the fly ash falls into the
fly ash chamber. 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

7
Operating conditions
18
gas temperature, the boiler will switch to normal
output control.
Flame monitoring
If the burning chamber temperature fluctuates
greatly during operation, the boiler will switch off.
Antifreeze
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 65 °C.
Lambda control
The amount of material 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. Therefore, it is not necessary to re-
set the combustion after the silo is filled.

Temperature manager
8
19
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 schema –example)

8
Temperature manager
20
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 (see figure 8.2). Caution: Consider the
set minimum requirement.
Figure 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 figure 8.3). Caution: Consider the set minimum
requirement.
Figure 8.3: Example temperature manager with buffer and difference