Viessmann VITOFLAME 200 Operating instructions

Service instructions
for heating engineers
Vitoflame 200
Gas pressure jet burner (typeVGA)
for Vitola and Vitorond 200
rated output 15 to 63 kW
See notes on applicability, page2.
VITOFLAME 200
5692449 GB1/2002 File in: Service folder

General Information
2
Safety instructions
Please follow these safety instructions closely to prevent accidents and material losses.
Work on the equipment
Installation, initial start−up,
maintenance and repairs must only
be carried out by a competent
person (heating engineer/
installation contractor) (EN50110,
part1, and VDE1000, part10 or local
regulations).
Before working on the equipment/
heating system, isolate the mains
electrical supply (e.g. by removing a
separate mains fuse or by means of
a mains electrical isolator) and
safeguard against unauthorised
re−connection.
Disconnect the system from the
mains electrical power by means of a
device which simultaneously isolates
all non−earthed conductors with at
least 3 mm contact separation.
When using gas as fuel, also close
the mains gas shut−off valve and
safeguard against unauthorised
re−opening.
Work requiring the control unit to be
opened must not subject internal
components to electrostatic
discharges.
Work on gas equipment
This must only be carried out by an
approved installer.
Observe all commissioning work for
gas installations specified by
TRGI’86/96 or TRF1996 or local
regulations.
Repairs
It is not permitted to carry out
repairs on components that fulfil a
safety function.
Use only original Viessmann spare
parts or equivalent, which have been
approved by Viessmann.
Initial start−up
This must be carried out by the
system installer or a commissioning
engineer designated by him; all
actual values should be recorded in a
commissioning/service report.
Instructing the system user
The system installer must hand the
operating instructions for this
system to the user and instruct
him/her in the operation of the
system.
¨Safety instructions
In this instruction manual, this
heading denotes information which
must be observed to prevent
accidents and material losses.
¨Caution
In this instruction manual, this
caption denotes actions that must be
avoided to prevent accidents and
material losses.
This symbol is a reference
to other instructions which
must be observed.
Applicability
Applicable to burners from serial no.:
7143681 100001kkk
7143682 100001kkk
7143683 100001kkk
7143684 100001kkk
7143685 100001kkk
7143686 100001kkk
7143687 100001kkk
7143688 100001kkk
Operating and service documents
1. Complete and separate the customer registration card:
HHand the system user this part
for safekeeping.
HKeep the heating engineer
portion.
2. Keep all parts lists, operating and
service instructions in the folder
and hand this over to the system
user.
5692449 GB

Contents
3
Page
General Information Safety instructions2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Applicability2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating and service documents2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Initial start−up,
inspection and maintenance
Procedure summary4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Implementation5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting Procedure summary16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnosis17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Additional information Specification21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard values for burner settings22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nozzle pressure table 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mixer setting 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas throughput subject to operational net calorific value (HuB) 22. . .
Ignition and ionisation electrode 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard values for sensor plate, restrictor and blast tube24. . . . . . . . . .
Component summary25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring diagram27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts list29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Declaration of conformity 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manufacturer’s certificate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
NO TAG
Initial start−up/service report36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5692449 GB

Initial start−up, inspection and maintenance
4
Procedure summary
Initial start−up steps
Steps for twice annual inspection
Maintenance steps
I M 1. Initial start−up Page 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I M 2. Setting the rated output Page 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I M 3. Air volume fine adjustment Page 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M4. Checking the burner Page 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M5. Air pressure switch Page 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I M 6. Heating system shut−down Page 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I M 7. Checking the electrical connections Page 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IM8. Cleaning the burner Page 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IM9. Checking the blast tube fixings Page 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IM10. Checking the fan fixings Page 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I M 11. Cleaning the sensor plate (if necessary) Page 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I M 12. Checking, adjusting and replacing (if necessary) the ignition and ionisation
electrodes Page 12
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M13. Burner installation on the burner housing Page 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IM14. Checking both gas train valves Page 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I M 15. Checking the gas train filter insert (manufacturer: Dungs),
and replacing, if necessary Page 14
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I M 16. Checking the gas train (manufacturer: Kromschröder) Page 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IIM17. Checking all gas connections for leaks Page 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I I M 18. Measuring the ionisation current Page 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5692449 GB

Initial start−up, inspection and maintenance
5
Implementation
To obtain optimum combustion values, it is essential that the burner is
adjusted with the boiler heated to operating temperature.
Check the CO content, CO2content, flue gas temperature, room temperature
and chimney draught after 2minutes operation and at 60ºC boiler water
temperature with fitted burner hood.
Remove the burner hood before commencing maintenance work.
1.Initial start−up
Maint.Initial start−up
Service instructions
boiler control unit
Please note:
Function sequence during initial
start−up, see page 17.
During the initial start−up the system
can enter a fault state, if it has
insufficient gas in the supply line
(fault lamps on the control unit and
on the burner illuminate).
Purge the gas line again and unlock
the burner control unit.
1. Check the heating system
pressure.
2. Open the gas shut−off valve.
3. Switch on the mains electrical
isolator (outside the installation
room).
4. Switch on the system On/Off
switchBon the control unit.
If the fault indicator lampAon
the control unit lights up, press the
reset button; press the reset
buttonCon the burner control
unit.
5692449 GB

Initial start−up, inspection and maintenance
6
Implementation (cont.)
2.Setting the rated output
Maint.Initial start−up
Check the type of gas with your local gas supplier.
The burner is factory−set to natural gas E.
Adjust the nozzle pressure for operation with natural gas LL according to
table22.
Record the type of gas in the commissioning/service report (you will find this
report on pages36 and37).
Idle pressure
1. Close the gas shut−off valve.
2. Loosen the screw in the test
nippleA but do not remove.
3. Connect the U−shaped pressure
gauge.
4. Open the gas shut−off valve.
5. Measure the static pressure
(max. 50mbar).
6. Record the actual value in the
service report.
You will find the commissioning/
service report on pages36 and37.
5692449 GB
Gas train (make: Kromschröder)
Gas train (make: Dungs)

Initial start−up, inspection and maintenance
7
Implementation (cont.)
2.Setting the rated output (cont.)
Maint.Initial start−up
Supply pressure
7. Start up the burner.
8. Check the supply pressure (flow
pressure), see the table below.
9. Record the actual value in the
service report.
10. Close the gas shut−off valve.
11. Remove the U−shaped pressure
gauge and close test nippleA.
Initial start−up, see page5.
The supply pressure (flow
pressure) should be between
20and25mbar.
The gas governor is factory−set to
10 mbar.
Do not change this setting.
You will find the service report on
pages36 and37.
Supply pressure Check
less than 15 mbar Do not change the settings and contact the gas supply
company.
15 to 18 mbar Attention: The boiler may only be temporarily operated
with these settings (emergency operation).
Notify your gas supply company.
18 to 50 mbar Start up the boiler.
above 50 mbar Install a separate gas pressure valve with zero off
upstream in the boiler system, and regulate the pressure
to 20 mbar.
Notify your gas supply company.
5692449 GB
Gas train (make: Kromschröder)
Gas train (make: Dungs)

Initial start−up, inspection and maintenance
8
Implementation (cont.)
2.Setting the rated output (cont.)
Maint.Initial start−up
Nozzle pressure
13. Loosen the screw in the test
nippleBbut do not remove, and
connect the U−shaped pressure
gauge.
14. Open the gas shut−off valve and
start the burner.
15. Check the nozzle pressure in
accordance with the Wobbe
index and the output in the
nozzle pressure table on page22.
16. Check and, if necessary, adjust
the nozzle pressure.
17. Record the actual value in the
service report.
During the adjustment, check the
gas throughput by means of a
volumetric test.
You will find the service report on
pages36 and37.
Burner with gas train
(make: Kromschröder) type CG10:
The adjusted gas pressure will be
present approx. 30seconds after the
burner has started.
Adjust the nozzle pressure on the
setscrewCusing an Allen key (size
2.5). Continue with item19.
Please note:
+: more gas
³higher nozzle pressure
−: less gas
³lower nozzle pressure
Burner with gas train
(make: Dungs) type MBDLE405B01:
The adjusted gas pressure will be
present approx. 30seconds after the
burner has been started.
HMove the cover over the
setscrewCaside.
HAdjust the nozzle pressure on the
setscrewCusing a screwdriver.
Do not turn the pressure regulator
outside its setting range. Turn the
setscrewConly as long as the
nozzle pressure noticeably changes.
The main volume butterfly valveD
should be turned fully to "+".
Please note:
+: more gas
³higher nozzle pressure
−: less gas
³lower nozzle pressure
5692449 GB

Initial start−up, inspection and maintenance
9
Implementation (cont.)
2. Setting the rated output (cont.)
Maint.Initial start−up
Start gas volume
The opening characteristics of the gas solenoid valve have been matched to
the boiler and have been preset at the factory.
Generally, you do not need to change this setting.
Please note:
If you do not wish to change the start gas volume, continue with item19.
18. For gas trains by Dungs type
MBDLE405B01 (if required):
HSet the quick action (opening
characteristics) with protective
cap positioned upside downE.
For pulsating burner start:
Rotate to the right³reduced
quick action (less gas during the
burner start).
When the ionisation current
during the start−up phase is too
low:
Rotate to the left³increased
quick action (more gas during
the burner start).
HFit the protective cap.
19. Close the gas shut−off valve,
remove the U−shaped pressure
gauge and close test nipple A
(see page8).
20. Start up the burner.
Ionisation current at least 3 µA.
Checking the ionisation current see
page15.
Safety instructions
Check the test nipple for gas leaks.
3.Air volume fine adjustment
Maint.Initial start−up
The air valve for regulating the air volume for Vitola boilers is factory−set.
Only make one adjustment during the initial start−up to match the system to
local conditions or to Vitorond.
The CO2content in the flue gas should be approx. 9.5%.
Test port (approx. 10 mm ∅) at a distance of two to three times the diameter
of the flue pipe behind the boiler adaptor.
Record the final values in the service report (you will find this report on
pages36 and37).
Ensure that the flue pipe is sealed at the boiler adaptor; otherwise infiltrating
air will falsify the measuring results.
ATest nipple for the static burner pressure
BAir damper setting
5692449 GB

Initial start−up, inspection and maintenance
10
Implementation (cont.)
4.Fully check the burner
Maint.
Record the actual values in their true
sequence in the service report on the
last pages of this manual.
Safety instructions
Measure the CO value before and
after any work on gas appliances, to
prevent any health hazards and to
ensure perfect system conditions.
5.Air pressure switch
Maint.
The air pressure switch is factory−set to the respective switching point
(1.5mbar); generally, you do not need to adjust this setting.
6.System shut−down
Inspection Maint.
1. Isolate the mains electricity supply
and take measures to prevent
re−connection.
2. Pull the plug−connectorfA from
the burner.
3. Close the gas shut−off valve.
7.Checking the electrical connections
Inspection Maint.
Check the plug connectors on the
burner components and their cable
grommets for tightness.
5692449 GB

Initial start−up, inspection and maintenance
11
Implementation (cont.)
8.Cleaning the burner
Inspection Maint.
1. Set the burner to maintenance.
2. Clean the housingC, the flame
tubeA, the mixerBtogether
with the ignition and ionisation
electrode and the impellerD.
3. Check the gas outlet holes in the
sensor plate for contamination
and clean, if required (see item 11
on page12).
Cleaning the combustion
chamber and hot gas flues,
see boiler service
instructions.
9.Checking the flame tube fixings
Inspection Maint.
See illustration under item 8.
10.Checking the impeller fixings
Inspection Maint.
See illustration under item 8.
5692449 GB

Initial start−up, inspection and maintenance
12
Implementation (cont.)
11.Cleaning the gas outlet holes in the sensor plate (if necessary)
Inspection Maint.
1. Remove the cables from the
electrodesHand .
2. Loosen the electrode holdersK
andA, and remove the ignition
and ionisation electrodes.
3. Remove the nut from the earth
electrodeFand unscrew the
electrode.
4. Unscrew the Allen screws from
the sensor plateE.
5. Remove the sensor plateE, the
spring washerDand the end
plateCfrom the mixer
assemblyBand clean.
6. Installation in reverse order.
Please note:
For alignment of the end plate C
and electrodes F, Gand Hsee
page 23.
12.Checking,adjustingandreplacingignitionandionisationelectrodes(ifnecessary)
Inspection Maint.
For setting values see page23.
13.Burner installation on the burner housing
Maint.
5692449 GB

Initial start−up, inspection and maintenance
13
Implementation (cont.)
14.Checking both gas train valves for leaks
Inspection Maint.
1. Loosen the screw in the test
nippleAbut do not remove.
2. Loosen the screw in the test
nippleBbut do not remove.
3. Connect the U−shaped pressure
gauge with a manual pump to the
test nippleB.
4. By gently activating the manual
pump build a test pressure of
approx. 50 mbar.
5. Wait approx. 5 minutes for the
temperature to level out and then
observe the display on the
U−shaped pressure gauge:
If the displayed pressure does not
fall within a further 5 minutes by
more than 1 mbar, the gas train is
tight³continue with step6).
Otherwise the system leaks−in
that case return the gas train to
Viessmann Werke for tests.
6. After the test, close both test
nipples by inserting screws.
5692449 GB
Gas train (make: Kromschröder)
Gas train (make: Dungs)

Initial start−up, inspection and maintenance
14
Implementation (cont.)
15.Checking the gas train filter insert (make Dungs),
and replacing, if necessary.
Inspection Maint.
1. Close the gas shut−off valve.
2. Unscrew the filter lidD.
3. Withdraw the filter elementB.
4. If necessary, clean or replace the
filter element.
5. Replace the filter lid gasketC.
6. Secure the filter lidD.
7. Check the breather hole in plugA
and clean, if necessary.
16.Checking the gas train (make: Kromschröder)
Inspection Maint.
Visually check the dirt trap in the gas
train inlet.
17.Checking all gas connections for leaks
Maint.Initial start−up Inspection
1. Insert new gaskets in all fittings,
which have been opened.
2. Check the gas train inlet
connections for leaks.
3. Start up the burner.
4. Check the gas train outlet
connections for leaks.
Initial start−up see page5.
5692449 GB

Initial start−up, inspection and maintenance
15
Implementation (cont.)
18.Checking the ionisation current
Maint.Initial start−up Inspection
1. Switch off the mains electrical
isolator.
2. Separate the plug connection of
the ionisation current cable (red
cable).
3. Switch on the mains electrical
isolator.
The system should then perform a
fault shut−down.
4. Switch off the mains electrical
isolator.
5. Connect an ionisation current
measuring device or
Testomatik−Gas.
6. Switch the mains electrical
isolator on and check the
ionisation current
(min. 3 µA).
7. Record the actual value in the
service report.
8. Switch the mains electrical isolator
off, remove the test equipment and
reconnect the plug connector of
the ionisation current cable.
9. Switch on the mains electrical
isolator.
Please note:
For checking with TestomatikGas,
the test cable no.1 is required. You
can also carry out this check with a
multimeter.
You will find the service report on
pages36 and37.
5692449 GB

Troubleshooting
16
Procedure summary
Diagnosis 1. Establish fault/ascertain the system characteristics.
2. Check for the corresponding cause of the fault in the diagnostic tables.
3. Establish the action required from the table.
Remedy 4. Correct the fault.
5692449 GB

Troubleshooting
17
Diagnosis
Function sequence (see page 27):
AStart command
Switching on by thermostat.
tw Delay: approx. 3 s
Air pressure switch and flame
relay are checked for correct
contact position.
t10 Default for the air pressure
response: min. 5 s
After expiry of this delay, the
set air pressure should be
established, otherwise there
will be a fault shutdown.
t1 Pre−purge time: min. 30 s
Purging the combustion
chamber and the secondary
heating surfaces.
t3 Pre−ignition time: approx. 2 s
During the pre−ignition time
until the expiry of the safety
time t2, the flame relay is
forcibly pulled up. Fuel is
released after t3 is expired.
t3n Ignition time
Ramp up during the safety
time (TSA).
TSA Safety time: max. 5 or 3 s
At the end of TSA (ramp−up
safety time) a flame signal
needs to be present at input 1
of the flame signal amplifier
and must remain steady until a
controlled switch−off, otherwise
the flame relay drops out, the
burner control unit triggers a
fault shut−down and is locked in
the fault position.
t4 Interval time
Burner control unit
Hin fault state
− Diagnosis of fault causes:
− wait at least 10 s
− press the reset button Aat
least for 3 s.
− read the flashing code of the
fault lamp (see fault table).
− after every flashing code a
break of approx. 3 s.
− reset, i.e. press the reset button
A0.5 to 3 s long.
Hoperational
− press the reset button A
0.5to3s long, to reinstate the
system operation.
Red fault lamp Billuminates
constantly
The green signal lamp C
illuminates
5692449 GB

Troubleshooting
18
Diagnosis (cont.)
Fault/system characteristics Flashing
code red
Cause of fault Check
Burner does not start,
demand lamp does not
illuminate.
No voltage. Check the fuse in the control unit,
check the electrical connections, the
position of the ON/OFF switch on
the control unit and the mains
electrical isolator.
High limit safety cut−out
activated.
Press the reset button on the boiler
control unit.
Vitoair motor faulty. Replace the Vitoair motor.
Burner does not start
(voltage present),
demand lamp illuminated.
Gas flow pressure too
low, gas governor cuts
out.
Check the gas flow pressure. The
gas flow pressure should be at least
20 mbar; clean gas filter, if
necessary.
Gas burner control unit
faulty.
Replace the gas burner control unit.
Fuse in the leak detector
device blown.
Replace the fuse.
Fault during leak test
(fault lamp illuminates).
Check the gas train pressure nipple
for leaks.
If the valves leak, replace the gas
train.
Leak detector faulty. Replace the leak detector.
3×flashes
DDD
Burner motor faulty. Replace the burner motor.
19×flashes
DDDDDDDDDD
DDDDDDDDD
External voltage across
output terminals.
Check whether the burner control
unit receives external voltages (e.g.
via S3).
20 ×flashes
DDDDDDDDDD
DDDDDDDDDD
Internal device error. Replace burner control unit.
Burner does not start
goes into a fault state after
4×flashes
DDDD
Air pressure switch
faulty.
Replace the air pressure switch or
check its settings.
g
approx. 65 s. 4×flashes
DDDD
Ionisation cable or
electrode earthing.
Remove earthing.
The burner motor starts, but
during the pre−purge phase
3×flashes
DDD
Dirty air pressure switch
connection.
Clean the connection.
gppgp
the system creates a fault
shutdown. 3×flashes
DDD
Air pressure switch
incorrectly set or faulty.
Adjust or replace the air pressure
switch (see page 10).
3×flashes
DDD
Air pressure too low. Clean impeller (see page 11).
Burner starts up, but no
flame is formed.
2×flashes
DD
Ignition electrode poorly
adjusted.
Adjust correctly (see page 22).
2×flashes
DD
Ignition electrodes damp
and contaminated.
Clean ignition electrode.
2×flashes
DD
Insulation of ignition
electrode cracked.
Replace the ignition electrode.
2×flashes
DD
Ignition transformer
faulty.
Replace ignition transformer.
2×flashes
DD
Ignition cable earthing. Replace ignition cable.
5692449 GB

Troubleshooting
19
Diagnosis (cont.)
Fault/system characteristics Flashing
code red
Cause of fault Check
Burner starts up, but no
flame is formed.
2×flashes
DD
Insufficient combustible
gas mixture available.
Vent gas supply line to the outside.
Check with a test burner, if sufficient
combustible gas is available.
2×flashes
DD
Gas solenoid valves fail
to open.
Check electrical connection, voltage
across the gas train (230 V) and
replace the gas train, if necessary.
Burner starts up and
ignition is OK, but the
2×flashes
DD
Start gas volume poorly
adjusted.
Adjust start gas volume or opening
characteristics (see page 9).
g,
burner enters a fault state
after the expiry of the safety
period
2×flashes
DD
Ionisation current too
low (< 3 µA).
Check position of the ionisation
electrode (see page 22).
per
i
o
d
.
2×flashes
DD
While the gas train is
opened, the
voltagebrieflydips
below 180V.
Check the electrical installation.
The burner starts, the flame
is established, but the
system is shut down after a
short while (not a fault
shut−down).
Gas shortage. Clean or replace gas filter. Check the
gas governor settings.
Check the gas flow pressure.
The burner goes from
operation into a fault state,
7×flashes
DDDDDDD
Ionisation current too
low (< 3 µA).
Check location of the sensor
electrode and change, if necessary.
p,
when the flame is already
established. 7×flashes
DDDDDDD
Electrode body faulty. Measure ionisation current and
replace ionisation electrode or earth
electrode, if necessary.
7×flashes
DDDDDDD
Ionisation current too
low because of incorrect
burner settings.
Correct the burner settings.
7×flashes
DDDDDDD
Faulty earthing. Check the earthing.
7×flashes
DDDDDDD
Burner control unit
faulty.
Replace burner control unit.
18×flashes
DDDDDDDDDD
DDDDDDDD
The air pressure switch
opens during the
pre−purge or during
operation.
Check air pressure switch settings
and replace the switch, if necessary.
Clean the air pressure switch hose.
Flame extinguishes during
operation
7×flashes
DDDDDDD
Mixer assembly
contaminated.
Clean the mixer assembly.
Combustion errors through
pulsation.
7×flashes
DDDDDDD
Gas throughput too high. Set gas throughput in accordance
with the rated boiler output.
p
7×flashes
DDDDDDD
Mixer assembly (stage 2)
incorrectly adjusted.
Change mixer assembly settings
(see page 22).
7×flashes
DDDDDDD
Air damper incorrectly
positioned.
Correct the setting.
7×flashes
DDDDDDD
The combustion
chamber pressure is too
high.
Check pressure in combustion
chamber and clean boiler, if
necessary.
7×flashes
DDDDDDD
Start gas volume too
large or too small.
Adjust start gas volume or opening
characteristics (see page 9).
7×flashes
DDDDDDD
Incorrect flue gas
draught.
Check the flue gas draught
(chimney).
Co is formed or the burner
is very sooty.
Too little or too much air. Correct setting.
Check the boiler room ventilation.
5692449 GB

Troubleshooting
20
Diagnosis (cont.)
Fault/system characteristics Flashing
code red
Cause of fault Check
CO2content too low or O2
content too high.
Incorrect setting. Adjust the nozzle pressure in
accordance with the type of gas
used. Correct the air damper
setting.
Infiltrating air. Seal the flue pipe at the boiler
adaptor. Re−tighten the boiler door
screws and those on the flue outlet
cover.
Flue gas temperature too
high.
Gas throughput too high. Match the gas throughput to the
rated boiler output.
g
Boiler contaminated. Clean the boiler and correct the
burner settings.
Flue gas temperature too
low.
Gas throughput too low. Match the gas throughput to the
rated boiler output.
5692449 GB