kunzel PK 10 User manual

Operating manual
Pellet boiler
PK 10 and PK 20
October 6, 2010

Important!
This operating manual contains important information for the operator. The
boiler must be professionally installed and operated in order to avoid potential
accidents.
Familiarize yourself with the contents of this manual before installing and
operating the boiler.
Be sure to also comply with the regional regulatory provisions; they may differ
in full or in part from the requirements named in this manual. In this case, the
regulator requirements always have precedence! The master chimney sweep
responsible for your region can always provide information.
The company KÜNZEL would like to thank you for your trust!

Contents
1 General 5
1.1 Intended use ......................................... 5
1.2 Permissible fuel ....................................... 5
1.3 Safety ............................................ 5
2 Installation 6
3 The KÜNZEL PK wood pellet boiler 6
3.1 The type identification plate ................................ 6
3.2 Chimney connection .................................... 7
3.3 Description of operation and design ............................ 7
4 Control system 10
4.1 Boiler control system .................................... 10
4.2 Differential temperature control unit ............................ 10
4.3 Burner control unit ..................................... 11
4.3.1 Display and controls ................................ 11
4.3.2 User menu ..................................... 13
4.3.3 Service menu .................................... 14
5 Putting unit into service for first time 15
5.1 Settings on the boiler .................................... 15
5.2 Settings on the burner ................................... 15
5.3 Setting the output setting .................................. 15
5.4 Starting the burner for the first time after the unit is installed ............... 16
5.5 Setting the draft ....................................... 17
5.6 Emissions measurement ................................... 17
5.7 Setting the excess air .................................... 17
6 Daily heating 18
6.1 Switching on the burner ................................... 18
6.2 Switching off the burner .................................. 18
6.3 Manual ignition ....................................... 19
7 Filling and transport systems 19
8 Filling the pellet bunker 20
9 Maintenance and care 20
9.1 Monthly cleaning routine .................................. 20
9.1.1 Using the cleaning lever .............................. 20
9.1.2 Emptying the ashtray ............................... 20
9.2 Half-yearly cleaning procedure ............................... 21
9.2.1 Pellet burner .................................... 21
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9.2.2 Interim bunker (if present) ............................. 22
9.2.3 Dosage screw auger ................................ 22
9.2.4 Flue gas ducts .................................... 23
9.3 Annual cleaning procedure ................................. 24
9.3.1 Pellet bunker .................................... 24
9.3.2 Cleaning of the conveyor screw .......................... 24
9.3.3 Thermomix valve ................................. 24
10 What to do in the event of a malfunction 25
10.1 Causes and remedial actions) ................................ 25
10.2 Resetting the automatic circuit breaker ........................... 28
10.3 Resetting the temperature safety limiter .......................... 28
10.4 Setting the chamber full sensor ............................... 28
11 Technical data 30
11.1 Wiring diagrams ...................................... 32
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1 General
1.1 Intended use
This pellet boiler is approved for the operation of an open or closed circuit hot water heating system with
a permissible operating pressure of up to 3 bar and a maximum flow line temperature of 95◦C.
It is not permitted to operate the pellet boiler without a return flow booster. The operation of the return
flow booster is to be monitored. A 4-way mixing valve is sufficient as a return flow booster on systems
with a buffer tank.
The boilers supplied by KÜNZEL are stationary units that comply with the WEEE Directive. The elec-
trical and electronic components contained in the boilers do not fall within the remit of this directive and
will therefore not be taken back by KÜNZEL. Please take these components to the recycling depot.
We do not assume any liability for any malfunctions resulting from the use of non-genuine KÜNZEL
components. This particularly applies to control units, external materials handling equipment and fuel
pipes from other manufacturers. We also do not assume any liability for operational difficulties resulting
from inadequate hydraulic and/or exhaust gas systems. We reserve the right to make technical changes.
1.2 Permissible fuel
It is only permitted to operate this pellet boiler with fuels that comply with the Federal Immission Control
Ordinance (wood pellets manufactured from natural wood).
Permissible pellets have a diameter of6mm or 8mm. Thepellets must comply with the DIN-Plusstandard
or the PVA standard (Austrian Pellet Association). The fine fraction (proportion of pellets with a length
of less than 10mm) is not permitted to exceed 8% in the pellet bunker. The powder density must be less
than 0.75kg/dm3. Other fuels, in particular pellets that contain recycled materials, may not be used.
The specified cleaning interval applies to pellets that comply with the DIN-Plus standard.
For reasons of operational safety and environmental protection the use of fuels other than pellets
that comply with the DIN-Plus or PVA standards is not permissible!
1.3 Safety
•Installation, service and other work may only be performed by trained specialists in accordance
with the applicable standards.
•The KÜNZEL pellet burner is equipped with the following safety devices:
–Burnback protection: The spreading of the fire to the rear is prevented by a discharge chute,
a temperature sensor and a fuel supply hose manufactured from special plastic.
–A temperature sensor measures the temperature in the discharge chute and regulates the out-
put as soon as the temperature exceeds the „reduction limit“ . The temperature sensor in the
discharge chute switches the burner off if, despite the output limiter, the temperature in the
discharge chute rises above the „deactivation threshold“ .
–A supply hose manufactured from special plastic, which melts at an elevated ambient temper-
ature (does not burn) and interrupts the connection between the pellet feed mechanism and
the burner. Hoses from other manufacturers may not be employed! No combustible parts
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or materials are permitted within a radius of 40 cm from the supply hose. Combustible
parts or materials are also not permitted to be located above or below the supply hose!
–The burner is equipped with a microswitch, which means that the burner cannot be run out-
side the boiler.
–Every time the unit is restarted after deactivation of the burner the fan runs for an additional
10 minutes in order to burn any pockets of embers that may be present.
–The pellet burner may not be operated unless the hood is properly installed!
– It is never permissible to allow a vacuum to form at the filling spout of the pellet burner.
– Please note: The burner must have performed a burnout procedure before the pellet bunker is
filled! Switching it off at the mains power switch is not sufficient because this action switches
off all of the monitoring equipment as well. Please read section 8on page 20 to learn more
about this.
2 Installation
When operating a KÜNZEL pellet boiler it is recommended to always fit a buffer tank with a capacity of
about 500 l to the system. Fitting a buffer tank to the system extends the length of the burner run times,
which markedly reduces the emission of pollutants, as well as wear and tear.
Please consult your heating installer about the precise system set-up.
Please consult the installation manual, which is supplied separately with the boiler.
3 The KÜNZEL PK wood pellet boiler
3.1 The type identification plate
Figure 1: The type identification plate
If you have any queries or complaints about your boiler, please always refer to the six-digit production
number/unit number/boiler number and the year of manufacture. This number can be found on the type
identification plate.
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The type identification plate is located behind the ash hatch. Immediately below it is a welded plate with
the boiler number.
3.2 Chimney connection
The exhaust gas duct to the chimney should be as short as possible, without any bends and installed at a
slight incline. The connection to the chimney should have anaerodynamic design that curves upward. The
connector joining the furnace and the chimney must comply with EN 1856-2:2004 and have the required
identification marking (CE). In accordance with EN 1856-2:2004 non-insulated connectors must be kept
at least 40 cm away from combustible components. We recommend the use of insulated connectors.
The figures required for the chimney design calculations can be found in the technical data listed in
section 11 on page 30. Calculated chimney diameters that are smaller than the flue gas branch of the
boiler are not permissible.
Please note: Please note that the low exhaust temperatures occurring during prolonged operation may
mean that it is necessary to fit a moisture-resistant chimney (thermal conductivity factor - resistance
group I in accordance with DIN 18160/T1).
Before connecting the pellet boiler to an existing chimney, subject it to a chimney calculation or obtain
a chimney report. Before commencing with the installation it is essential to obtain the approval of your
local master chimney sweep.
An insufficient draft or a dirty flue gas system will be detected by the burner via the temperature
sensors. The display unit of the burner control unit will then display the fault message „flue draft
insufficient“. Should this occur, the control lamp will switch to yellow and thereby show that the burner
is in emergency operation mode. The display unit will then alternately show the above fault message
and the fault message „reduced output“. If the problem cannot be handled by reducing the output of the
burner and dangerous temperatures occur at the sensors, the burner will be switched off once the upper
temperature limit is reached.
3.3 Description of operation and design
The pellets are transferred by a screw conveyor from an external storage unit to the filling spout of the
burner. They are then transferred by a dosage screw auger into the discharge chute, after which they fall
into the brazier. The drop distance serves as burnback protection.
The level of pellets in the filling spout is monitored. The LED of the chamber full sensor goes out if the
level of the pellets in the connection has fallen below the measurement range of the chamber full sensor.
In normal operation, the external conveyor screw starts to run two minutes after the LED goes out and
then remains active until the LED lights up once again and the filling spout is filled with pellets. The
control unit is to be set so that the motor of the external conveyor screw runs for a maximum of two
minutes. If the filling spout of the burner is not filled with pellets in this time, the display lamp switches
from green to red and the text „external !!! MALFUNCTION !!!“ appears in the display unit. (see also
„Control panel - description of operation“ ).
According to the filling system employed, it can therefore be necessary to adjust the parameter 41 in
the service menu of the burner control unit. For more information on this subject please refer to section
4.3.3 on page 14.
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A fan provides the burner with primary and secondary air. This is distributed within the brazier so that
the correct amount of air is available for both the primary and the secondary combustion processes.
Ignition takes place automatically with air that has been pre-heated by a heating coil. The integrated
temperature sensor (flame sensor) detects when ignition has taken place. If ignition does not take place,
the brazier is automatically emptied and the burner attempts to restart the combustion process. If ignition
fails to take place once again, the burner is switched off.
Figure 2: Pellet boiler
The burner output depends on the output setting. It can be set in the menu of the burner control unit in 1
kW steps between the minimum permissible output and the maximum permissible output. If the burner
is equipped with the optional auxiliary sensor, the output setting is set automatically.
The maximum and minimum settings are set when the plant is put into service for the first time. The
burner output should be adjusted according to the load requirement. The efficiency specifications refer
to the maximum output.
Boiler type Maximum output Minimum output Recommended output
PK10 13kW 7kW 10kW
PK15 17kW 10kW 13kW
PK20 21kW 13kW 16kW
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For optimal system operation, the burner should cycle as little as possible. It is more economical to let the
boiler run at a low load for a long time than to have it continually stopping and re-starting. We therefore
recommend to first set the burner to about 75% of the maximum permissible boiler capacity, because the
building only actually requires the calculated heat load for a very few days every year. On these days, the
burner can be set to the maximum permissible boiler capacity via the menu.
These displayed output values refer to a pellet weight of 675 g/litre and a calorific value of 4.8 kWh/kg.
When using pellets with a different volumetric weight or calorific value, the corresponding values for
volumetric weight and calorific value must be adjusted to compensate for differences in heating per-
formance and combustion values. However, this is generally only the case when 8 mm pellets are used
instead of 6 mm pellets (standard). Using good quality pellets ensures a high degree of operational safety
and efficiency.
Figure 3: Moveable grate
The patented moveable base in the burner combustion chamber scrapes slag and dirt from the combustion
chamber and transfers them into the ash pan. The burner is automatically cleaned if either the boiler
thermostat is triggered or a specified amount of pellets has been consumed. The moveable grate is moved
in and out. This means that the brazier is cleaned before every re-start or after a specified number of
metered pellet charges.
Figure 4: Safety/ microswitch
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4 Control system
4.1 Boiler control system
Located directly on pellet boiler are a thermometer (to display the boiler temperature), a boiler thermo-
stat, the temperature safety limiter and the mains power switch. As soon as a differential temperature
control unit or a weather-regulated heating controller is used, the boiler thermostat must be turned to its
maximum setting (turn as far to the right as it will go). These control units assume responsibility for the
thermostat function and otherwise cannot operate properly.
Figure 5: The boiler control system
4.2 Differential temperature control unit
Figure 6: The differential temperature control unit
The differential temperature control unit is required so that the pellet boiler can be operated in conjunc-
tion with a buffer tank. It monitors the filling and emptying of the buffer tank and controls the boiler
circulation pump and the burner. This ensures that the pellet boiler is not switched on too often and that
longer burner times are achieved. This avoids unnecessary starts which lead to high electricity consump-
tion and unnecessary emissions.
The differential temperature control unit monitors the buffer tank temperatures, enables the burner and
controls the boiler circulation pump. Please consult the operating manual supplied with the control unit
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before commencing with the installation and adjustment operations. KÜNZEL recommends the follow-
ing default settings:
Sensor Function Recommended value
T1 Pump start 70◦C
T2 Buffer tank, top min. 55◦C
T3 Buffer tank, bottom max. 70◦C
1. The burner starts when the temperature T2 (upper buffer tank temperature) falls below the set
temperature value T2 (45◦C -70◦C). The factory setting is 70◦C.
2. The burner stops when the temperature T3 (lower buffer tank temperature) rises above the set value
T3 (55◦C - 80◦C). The factory setting is 70◦C. The buffer tank is now completely filled.
3. The pumps runs:
•When the temperature T1 is higher than the set temperature T1 (boiler is warm).
•When the temperature T1 is higher than the set temperature T2 (storage tank is colder than
boiler).
4. The pump stops:
•When the temperature T1 is more than 3◦C below the set value T1 (after-run period of 3
minutes).
•When the temperature T2 is higher than the temperature T1, the buffer tank isnow completely
filled (after-run period 3 minutes).
We recommend the fitting of the KÜNZEL-BD600A, which is a weather-regulated heating controller, so
that our customers can enjoy a high degree of heating comfort.
4.3 Burner control unit
4.3.1 Display and controls
Figure 7: The control panel
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A Control lamp: green = normal operation, yellow = warning, red = fault indication
Start/Stop: All processes in the burner are interrupted (total stop)
when this switch is pressed. If it is pressed again, the burner
seamlessly resumes its operation at the same point in the cycle.
, Changing value, paging through service menu
Paging through user menu (press briefly)
Pressing the menu button once in the service menu permits the value
to be changed (the figures blink).
Change the value by using the plus and minus buttons. Save/confirm the value
(press for three seconds); the display unit shows the message „saving data“ .
To call up the service menu press both buttons for three seconds (or longer).
To return to the user menu, press both buttons once again for three seconds.
When resetting the unit, keep the plus and menu button depressed before the
welcome message disappears. All values are reset to the factory setting.
Resetting the unit means that all changes are lost.
The menu system of the KÜNZEL pellet boiler includes two menu levels, i.e., a user menu and a service
menu. The status of the user menu appears when the unit is started up. PLEASE NOTE: The status is
automatically reset if no switch is pressed for five minutes.
Stop/Start: Press the On/Off button. All processes in the burner are interrupted
(total stop) when this switch is pressed. If it is pressed again,
the burner seamlessly resumes its operation at the same point in the cycle.
Change value: Press the menu button. The value blinks.
Set the desired value using the minus or plus buttons.
The value is saved by pressing the menu button for three seconds
The display unit shows the message „saved in memory“ .
Menu selection: To call up the service menu press both buttons simultaneously for three
seconds (or longer). To return to the user menu, press both buttons
once again for three seconds.
Resetting: Switch off the power supply to the burner and switch it back on again.
Keep the menu and plus buttons depressed before the welcome message
disappears. All values are reset to their default setting. Resetting
the unit deletes any changes that have not been saved.
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4.3.2 User menu
Display message Meaning Set value
Pellet consumption Shows the current rate of pellet consumption.
Output selection The burner output can be set to between minimum and the maximum
output using this feature. This occurs automatically if the burner
is being operated with a dedicated boiler sensor (not yet available).
Ash scraping Shows how many kilos of pellets have to be burnt before mandatory
after cleaning procedure takes place. This parameter is only
important if the burner is running in continuous operation.
Spec. weight/ This parameter can be used to set up the burner to use different
calorific value standardized pellets (6 mm or 8 mm).
This value may only be changed by a specialist!
Autostart after Shows whether the burner should automatically start up after it
switching on has been switched on or after a power supply breakdown
Manual ignition This feature can be used to ignite the burner manually if the igniter
is defective. The burner then runs in ember conservation mode. This is an
emergency feature and should only be used under such circumstances.
End operation This feature switches the burner off properly. It no longer responds
to the boiler control unit and remains off. The burner can be restarted
once again using the ON / OFF button. If it is intended that the boiler
remain out of operation for an extended period of time, the boiler must
also be switched off at the mains power switch.
Manual metering Manual starting of the internal dosage screw auger. This feature is only
of pellets necessary for the filling of an empty burner.
It will only work when the burner is set to „manual off“ .
Manual Manual starting of the ext. conveyor screw. This feature is only
ext. feed necessary to fill the empty external conveyor screw.
It will only work when the burner is set to „manual off“ .
Operation with ... Display of current output setting –
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4.3.3 Service menu
The settings in this menu may only be changed by trained specialists!
Display with Explanation
factory settings
23 Metering signal This parameter is essential for setting up the combustion air.
If this value is increased, more pellets are fed into the burner
(less O2 in the exhaust gas). If this value is reduced, fewer
pellets are fed into the burner (more O2 in the exhaust gas).
The value is adjusted proportionally for all output settings.
For this reason, it may only be changed by a specialist using
measurement equipment!
41 External conveyor This figure shows how long the unit will wait for the
screw chamber full sensor to give a signal after the external
alarm time conveyor screw is switched on. This value can be increased
if there are problems with the filling system.
43 Ext. conveyor screw Period (in seconds) for which the external conveyor screw runs
after-run period after the chamber full sensor has reacted.
49 Reduction - If the temperature in the discharge chute reaches this value, the burner
limit will attempt to prevent it increasing any further by reducing the output.
The control lamp turns red. The message „flue draft low“ appears
in the display. Clean the boiler and the exhaust system.
56 Standby Maximum period for which the burner will run in ember conservation
maximum duration: 1:00 h mode without being activated. (only important for emergency operation
mode with defective igniter)
59 Pellet consumption Shows the rate of pellet consumption. Once more than 6 tonnes of
pellets have been consumed, the message „Problem - maintenance required“
appears in the display. The burner should now be maintained by a specialist,
but continues to run normally.
Reset by keeping the MENU button depressed for more than 3 seconds
60 Minimum output Lower limit of the output setting:
selection See table 1on page 8
61 Maximum output Upper limit of the output setting
selection See table 1on page 8
63 Fault message By pressing the menu button users can access the list showing
list the most recent fault messages.
80–84 Currently not in operation
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5 Putting unit into service for first time
5.1 Settings on the boiler
Firstly, the control dial for the boiler set-point temperature should be set. If the boiler is being run in
conjunction with the differential temperature control unit or a weather-regulated heating controller, the
control dial must be turned to the maximum setting (turned as far to the right as it can go).
If neither of the above controllers is used, the boiler set-point temperature is set at the boiler control unit.
5.2 Settings on the burner
When delivered and after a reset, all of the burner parameters are set to the factory setting. These settings
permit the unit to operate in emergency mode. The following values, which differ from these factory
settings, are recommended by KÜNZEL for the basic set-up. However, this is no substitute for having the
burner set up precisely by a specialist. Enter the values determined during the commissioning procedure
in the following table so that you can set up the burner after a reset if needed.
In order to change these values, you must go into the specialist menu of the burner control unit. Press the
„-“ and „+“ buttons until you get into the menu. You can use the „- “ and the „+“ to move about within
the menu tree. Press the „menu“ button if you want to change a value. The value will start to blink. You
can now change the value using the „-“ and „+“ buttons. To save your changes keep the „menu button“
depressed for more than 3 seconds.
Please note: ONLY change the values specified in the table. Changing other values can lead to seri-
ous operational malfunctions. If you are uncertain, please consult KÜNZEL or your heating specialist.
If in doubt, reset the burner control unit.
Parameter Description PK10 PK15 PK20 Set value
23 Metering signal 0,80sec 0,80sec 0,80sec
41 External conveyor screw 5min 5min 5min
49 Reduction limit 70◦C 90◦C 70◦C
50 Alarm limit 90◦C 120◦C 90◦C
60 Min output 7kW 10kW 13kW
61 Max. output 13kW 17kW 21kW
5.3 Setting the output setting
As standard, the burner is supplied with a factory pre-setting of 9 kW. It is necessary to adjust the
burner output to match the boiler used. Please use the values listed in table 1on page 8.
Confirm the setting by repeatedly pressing the menu button until the message „Setting of output setting
xx kW “ is displayed. The output can be set using the „-“ and „+“ buttons and this setting can then
be saved by holding the menu button depressed for three seconds. The maximum output and minimum
output are determined by the boiler size and are pre-set as described above.
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5.4 Starting the burner for the first time after the unit is installed
PLEASE NOTE: When starting the burner for the first time, the dosage screw auger and the filling
spout have not yet been filled with pellets. The conveyor screws can be filled by using the corresponding
menu items in the user menu. When doing this, please also consult the table 5.
•Please check whether enough pellets are available in the bunker. The level to which the bunker has
been filled may not be below the inlet of the conveyor screw.
•Please ensure that the electrical cables between the burner and the boiler, and between the boiler
and the conveyor screw have been connected. In addition, ensure that the burner filling hose is
firmly secured in position.
•Now switch on the mains power switch on the boiler.
•Once a waiting period of two minutes has elapsed (the display will show the message „waiting for
pellets“ ), the conveyor screw will start to run. If the filling spout has not been filled within the
„alarm period“ the pellet feed mechanism will be switched off. The ON/OFF switch must then be
pressed again to give the conveyor screw another chance to fill the filling spout with pellets up to
the chamber full sensor. For more information about this, please read the item „manual ext. pellet
feed mechanism“ in sect. 5.
•Once the filling spout has been filled, the chamber full sensor reacts and switches the conveyor
screw off.
•The external conveyor screw can also be operated manually: The manual feeding of pellets is only
possible when the unit has been stopped. Press the ON/OFF button to switch the burner off. This is
necessary because the control unit is set to „autostart after activation“ and will attempt to continue
to run the unit. The display shows the message „switched off manually“ .
•Press the menu button until the message „manual ext. pellet feed mechanism“ appears. Keep the
„+“ button depressed so that the motor starts and let it run until the filling spout of burner has been
filled up to the chamber full sensor. The motor stops if the switch is released or the chamber full
sensor is reached.
•Once the filling spout has been filled, the dosage screw auger must be manually filled with pellets.
To do this, press the menu button repeatedly until the message „manual pellet feed“ is displayed.
Keep the „+“ switch depressed so that the motor starts. Let the motor run until pellets fall into the
brazier. Then release the switch.
•Press the ON/OFF switch to start the burner.
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5.5 Setting the draft
Let the burner run for 15 minutes before starting to set the draft.
•Insert the sensor of the draft meter in the draft measurement hole.
•Set the draft using the draught regulation damper so that the draft meter shows a reading of between
10 and 15 Pa.
For boilers subject to measurement requirements, the emissions measurement should take place at
least 2 weeks after commissioning so that the gases trapped within the components and door seals by
the manufacturing process can be escape.
5.6 Emissions measurement
Bei der Inbetriebnahme des Kessels wird der Brenner vom Kundendienst eingestellt. Zur Einstellung des
Brenners ist ein Messgerät notwendig.
When the boiler is commissioned, the burner is set up by the customer support service. A measuring
device is required for the setting up of the burner. For the emissions measurement, the boiler must be
at operating temperature and clean and the burner must be run at the highest permissible output for the
boiler type. For a clean combustion process to take place, the fuel pellets must be of high quality. Please
ensure that only pellets that comply with the DIN-Plus quality standard are used in your boiler.
•Let the burner run for a few minutes at the highest permissible output for your boiler and then
measure the CO2 and CO values with an exhaust gas sensor that is suitable for wood pellets.
•The following guidelines apply:
–At minimum boiler output, the average O2 content of the exhaust gas should be between 9%
and 12%, while at maximum boiler output it should be between 6% and 10%.
–At maximum boiler output, the average CO content of the exhaust gas should be less than
400 ppm (13% O2.) and at minimum output should be less than 750 ppm (13% O2).
–Variations in the O2 and CO content during the measurement procedure are normal and are
brought about by the boiler’s principle of operation.
5.7 Setting the excess air
It is essential that an exhaust gas sensor is used for air setting. The boiler must be at operating temperature
and clean and the burner must be run at the highest permissible output for the boiler type.
The air setting of the burner is performed exclusively using parameter 23 (metering signal) in the service
menu. The setting of other fan curve parameters may under some circumstances lead to a loss in the
regulating capability and must not be done under any circumstances!!! The settings applied affect the
entire power curve of the burner.
The default setting for your boiler type can be found in table 1on page 8.
Important: The metering signal may only be adjusted in a maximum of 0.02 sec. steps! Allow the
burner to run after a change for about 5 minutes and then test the exhaust gas. The measurement should
take place for at least 5 minutes.
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If the O2 content of the exhaust gas is too high, less combustion air is required. The metering signal is
lengthened in order to achieve this.
If the O2 content of the exhaust gas is too low, more combustion air is required. The metering signal is
shortened in order to achieve this.
6 Daily heating
6.1 Switching on the burner
•Switch on the mains power switch (the switch is located on the boiler); the burner will automat-
ically run at the last saved output setting if a run request is present. („Autostart after activation“
).
•When the boiler thermostat activates the burner, the filling spout is first filled with pellets (roughly
two minute waiting period), if the level of pellets in the chamber is below the chamber full sensor.
Then the brazier is cleaned. Then the run-up sequence starts. Pellets are fed in, the heating coil is
switched on, and the fan starts to run. The entire start sequence is set up to allow a rapid ignition
of the fuel and the lowest possible level of emissions. The start-up procedure takes roughly ten
minutes, whereupon the selected output setting is achieved.
6.2 Switching off the burner
IMPORTANT: Always switch off the power supply at the mains power switch if the system is to be put
out of operation for a lengthy period of time. When service operations are performed upon the burner, it
must be completely disconnected from the mains power supply. To do this, disconnect the burner plug.
Immediate power-down: The pellet feed mechanism and the fan are stopped. The remaining pellets stay
in the brazier and burn out there.
•Press the ON/OFF button. The display show the message „switched off manually“ . All of the
burner’s functions are switched off. This condition is described as the idle mode. If the ON/OFF
button is pressed once, the burner will recommence its operation at the point it left off. (according
to how long it has been switched off, it can either continue its operation or it will perform the
cleaning procedure and then initiate a re-start.)
•If the burner is to be switched off for an extended period of time, the power supply must be
disconnected using the mains power switch, once the display shows the message „Switched off
manually“ and the control lamp turns red. This ensures that the burner cannot be switched back on
unintentionally in the event of a power cut.
End operation: The pellet feed mechanism is stopped, the fan runs for a while („after-run period“ ) and
the brazier is cleaned of ash and residual pellets.
•If it is intended to clear the boiler of ash, the burner must first have cooled down and performed its
cleaning procedure. This feature is only activated when the burner is operating.
•Page through in the in the menu until the sub-item „End operation“ is reached. In order to activate
this feature, hold the menu button depressed for three seconds.
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•Then wait until the fan is no longer running and the ash scraper has stopped working. According
to the position reached at the time in the programme, this can take up to ten minutes. The display
shows the message „switched off manually“ and the control lamp turns red.
•If the burner is to remain switched off, disconnect the mains power supply using the main switch.
This ensures that the burner cannot be switched back on unintentionally in the event of a power
cut.
Tripping of the boiler thermostat: The burner receives a burn-out signal, the pellet feed mechanism
stops, the fan continues to run for a certain period („after-run period“ ). The burner starts automatically
when the boiler thermostat activates the burner once again. According to the residual temperature
(„run-up value“ ), this occurs with a warm-up phase or complete restart.
IMPORTANT: Only switch off the mains power supply once the fan has stopped running.
6.3 Manual ignition
PLEASE NOTE: Manual ignition should only be performed if the burner does not ignite normally (e.g.
defective heating coil), and should only be used to until the ignition system is repaired.
•Switch on the mains power supply of the burner and press the ON/OFF button to switch the burner
back off. This is necessary because the automation system is normally set to „Autostart upon start-
up“ . The display will show the message „switched off manually“ . The manual feeding of pellets
is only possible when the unit has been stopped.
•Now press the menu button repeatedly until the message „manual pellet feed mechanism“ appears.
Keep the „+“ button depressed and let the motor run for between 35 and 40 seconds.
•Open the boiler door. The burner swings out together with the door. The introduced pellets can
then be sprayed with barbeque lighter fluid and lit with a match or a lighter. Ensure you do not
bend over the brazier. Light it from the side instead. Caution, risk of burns!
•Having lit the pellets, swing the burner door back into the boiler and lock it in place.
•Now press the menu button again repeatedly until the message „manual ignition off“ appears.
Pressing the „+“ button switches the system to „manual ignition on“ . Then keep the menu button
depressed for three seconds until the message „data saved“ appears.
•Now press the ON/OFF button to start the unit. The burner starts with a delay of 3 minutes and
gradually starts to operate. PLEASE NOTE: The output setting corresponds to the desired
setting on standby without a time limit. This may not be changed while operating the unit
with manual ignition.
7 Filling and transport systems
We offer various systems for transporting fuel from the on-site pellet bunker or bag silo. More detailed
information can be found in the PK design folder or in our price list.
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8 Filling the pellet bunker
The pellet boiler must be shut down before the pellet bunker is filled by the fuel supplier.
Please note: Never switch the boiler off at the mains power switch while it is running. The burner
may still contain smouldering pellet residue, which could lead to hazardous situations arising when
the bunker is filled with pellets.
When ordering fuel, arrange for the supplier to telephone you at least one hour before the bunker is due
to be filled.
Perform a burn-out procedure with subsequent ash removal („end operation“ in the menu) and ensure
that the combustion chamber does not contain any smouldering or burning pellets. Then switch
the boiler off at the mains power switch and remove the connection hose between the burner and the
conveyor screw.
The bunker may only be filled under the supervision of a person trained in the operation of the
boiler.
9 Maintenance and care
Likeall technical equipment, your KÜNZEL pellet boiler must also be regularly maintained and serviced.
According to the cleaning procedures, different cleaning intervals must be observed. An additional thor-
ough maintenance routine should be performed before prolonged idle periods, e.g., during the summer
break. We recommend you to have a maintenance agreement with your heating specialist.
9.1 Monthly cleaning routine
9.1.1 Using the cleaning lever
There is a cleaning lever on the side of the boiler that activates the cleaning mechanism inside the boiler.
Cleaning the flue gas ducts markedly increases the heat transfer characteristics and therefore the effi-
ciency of the boiler. It is therefore a good idea to operate this lever as often as practicable. This should
be done every 1-3 weeks, according to how heavily the boiler is used. To clean the boiler, simply move
the lever backwards and forwards four times.
9.1.2 Emptying the ashtray
After the burning of about 1.5 t of pellets (depends strongly on the quality of pellets used), the ashtray
must be emptied. To do this, switch off the boiler and wait a sufficiently long period until the components
have cooled to a temperature at which they can be handled.
The wearing of protective gloves is recommended for the following tasks. The components in the com-
bustion chamber are dirty and under some circumstances could still be hot. Now the ash hatch can be
opened and the ashtray (arrow) removed. Ensure the hot ashes are not put into a container that either
contains combustible materials or that is combustible itself.
Remove all of the ash from the combustion chamber. The second, lower ashtray only has to be emptied
about twice a year when the flue gas ducts are cleaned.
PLEASE NOTE: Pure wood ash is an excellent fertiliser for the garden.
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