MHG Heating GZ 2 Guide

List of contents
Norms and regulations....................................................................................................................................................................... 4
Exhaust system and effective heat demand ........................................................................................................................................ 4
Modern conception ........................................................................................................................................................................... 4
Useful design..................................................................................................................................................................................... 4
Universal use ..................................................................................................................................................................................... 5
Two-stage Operation ......................................................................................................................................................................... 5
Easy Installation ................................................................................................................................................................................. 6
Instructions for using the burner ........................................................................................................................................................ 6
Leak test............................................................................................................................................................................................ 6
Rating of the gas ramps ..................................................................................................................................................................... 7
Gas compact ramp Rp 1“ and Rp 1¼“............................................................................................................................................... 7
Gas compact ramp Rp 1½“ and Rp 2“............................................................................................................................................... 8
Gas compact ramp DN 65 to DN 100................................................................................................................................................. 8
Gas ramps GZ 3 liquid gas ................................................................................................................................................................. 8
Setting of the switches in the motor valve connection box.................................................................................................................. 8
Gasburner and Gas ramps assembly GZ 2 - GZ 4 ................................................................................................................................ 9
Table of basic settings and dimensions GZ 2 - GZ 4 ............................................................................................................................ 9
Adjusting the burner........................................................................................................................................................................ 10
Position air guidance device GZ 3 and GZ 4...................................................................................................................................... 11
Air inlet nozzle................................................................................................................................................................................. 11
Settings ........................................................................................................................................................................................... 12
Spark electrode setting .................................................................................................................................................................... 12
Installation position Multiblock......................................................................................................................................................... 12
Fault diagnosis................................................................................................................................................................................. 13
Fault diagnosis MMI 810.................................................................................................................................................................. 13
Fault diagnosis TMG 740-3 and TMG 740-2..................................................................................................................................... 14
Troubleshooting .............................................................................................................................................................................. 15
Burner dimensions ........................................................................................................................................................................... 17
Connections .................................................................................................................................................................................... 18
Boiler connections ........................................................................................................................................................................... 18
Electric supply diagram .................................................................................................................................................................... 18
Assembly with silencer hood for GZ 3 and GZ 4 .............................................................................................................................. 18
Circuit diagramm GZ 2..................................................................................................................................................................... 19
Circuit diagramm GZ 3.0.................................................................................................................................................................. 20
Circuit diagramm GZ 3.1 - GZ 3.3 .................................................................................................................................................... 21
Circuit diagramm GZ 4..................................................................................................................................................................... 22
Maintenance and service.................................................................................................................................................................. 23
Guarantee ....................................................................................................................................................................................... 24
Spare parts ...................................................................................................................................................................................... 24
Manufacturer's certificate ................................................................................................................................................................ 25
EC Declaration of Conformity .......................................................................................................................................................... 26

Safety instructions – Please observe!
Please comply with the assembly, operation and maintenance instructions for installing and adjust-
ing the gas burner!
In Switzerland, the guidelines issued by PROCAL and those of the Vereinigung Kantonaler Feuerver-
sicherungen, VKF (Association of Canton Fire Insurances) must be observed, in particular the fire
guidelines "Thermal Heating Systems".
Please read this installation manually carefully before starting installation. We cannot assume any
liability or guarantee for damage caused by failure to comply with this installation manual!
Work which is not carried out properly can cause injury to persons or damage to property!
Work on the heating system yInstallation, commissioning, maintenance and servicing work
may only be carried out by an authorised firm of heating con-
tractors.
When working on burner and boiler yswitch off the heating system emergency switch and secure it to
prevent it being switched on again.
yshut off the oil feed pipe and secure it to prevent it being
opened unintentionally.
This symbol refers to instructions which must be heeded for your own safety and that of other people, and
to avoid damage to property.
This symbol refers to instructions which must be heeded for the gas burner to operate safety and function
correctly. It also draws attention to statutory regulations which need to be observed.

Installation-Operation-Maintenance GZ 2 - GZ 4 / 100 - 1450 kW
4
Norms and regulations
The following standards and regulations are to be observed
during installation and operation of the burner.
HeizAnlV
Heating system ordinance
FeuVo
Firing ordinance of the German federal states
1. BImSchV
First ordinance for implementation of the German Emission Pro-
tection Law
VDI 2035
Guidelines for preventing damage from corrosion and scale
formation in hot water heating installations
VDE
Regulations and special requirements issued by the energy util-
ity companies
EN 303, part 1 and part 2
Heating boilers with forced draft burners
EN 60335, part 1
Safety of household and similar electrical appliances
DIN 4705
Calculating the dimensions of chimneys
DIN 4751
Hot water heating installations – safety requirements
DIN 4755
Oil firing installations – construction, execution, safety require-
ments
DIN EN 267
Automatic forced draught burners for liquid fuels – definitions,
requirements, construction and testing
DIN 51603, part 1
Fuel oils extra light
DIN 57116
Electrical equipment of firing installations
Please comply with the valid regional building code.
Exhaust system and effective heat demand
Boiler, burner and exhaust system (chimney) constitute an oper-
ating unit; account must be taken of low exhaust temperatures
when reducing the output
For exhaust temperatures below 160°C, the system must be de-
signed so as to avoid damage from condensation.
The uncondensed (humid) flue gas volume is an important indi-
cation of the size of the flue gas installations an chimneys re-
quired.
It is advisable to install draft limiters (supplementary air sys-
tems) to achieve stable combustion values under varying condi-
tions and to reduce possible humidity in the chimney. These
should be installed in the chimney where possible, to avoid pos-
sible noises in the flue pipe.
Modern conception
The gas burners in the GZ 2 - GZ 4 series are fully automatic
two-stage burners in monobloc design. They are suitable for
natural gas and liquefied gas according to DVGW paper G 260,
designed according to DIN 4788, and tested according to
DVGW and CE.
The burners are equipped with automatic gas firing units for in-
termittent operation as per DIN EN 298 or DIN 4788; automatic
gas firing units for continuous operation on request.
The GZ 2 - GZ 4 gas burners are pressurised burners with very
high impeller pressing and a steep impeller characteristic line.
Because of these features and the variable adjustment of the air
admission nozzle, these burners are appropriate for modern
high-performance boilers with reversible flames as well as for
older natural draught boilers. The modern conception of the
two-stage GZ 2 - GZ 4 burners with a maximum output range
of 50:100% (GZ 2 - GZ 3) or 60:100% (GZ 4) guarantees ideal
graduation of the two load-stages depending on operating
conditions.
Useful design
Diecasting light metal case, power-dependent burner pipe and
high-performance mixing system, adjustable air admission noz-
zle and air damper servomotor for two-stage operation, A.C.
motor (GZ 2 - GZ 3.0) or threephase motor (GZ 3.1 - GZ 4), ig-
nition transformer, fan impeller, gas compact ramp (GZ 2 - GZ
3.0) or gas ramps assembly (GZ 3.1 - GZ 4), air pressure switch,
automatic firing sequence control with infrared flame detector
(GZ 2 - GZ 3) or ionisation flame control (GZ 4), internal plug
connections and plugs according to DIN 4791, mounting flange
with gasket and fastening screws.
Every burner is pre-tested.

GZ 2 - GZ 4 / 100 - 1450 kW Installation-Operation-Maintenance
5
Universal use
The adjacent diagram depicts the approximate performance
range of the different burner sizes as a function of the resis-
tance measured at the boiler's gas exit during operation. The
curves show maximum values and correspond with the model
certification according to DIN 4788.
The starting resistance of the boiler is of decisive importance to
the attainable burner performance.
Fig. 1: Performance diagram GZ 2
Fig. 2: Performance diagram GZ 3
Fig. 3: Performance diagram GZ 4
Two-stage Operation
The use of a modern, symmetrically designed high-performance
mixing system in conjunction with precisely functioning adjust-
ment at the compact gas ramps (GZ 2 - GZ 3.0) or at the gas
ramps assembly (GZ 3.1 -GZ 4) makes it possible to adjust out-
put precisely to heating requirements, resulting in optimum en-
ergy utilisation in both load stages with low-emission combus-
tion.
Two-stage operation is controlled by the air damper servomotor
which adjusts the air flow for the two load stages and switches
the gas solenoids in the compact gas ramps (GZ 2 -GZ 3.0) or
gas ramps assembly (GZ 3.1 - GZ 4) by adjustable cam control-
lers.

Installation-Operation-Maintenance GZ 2 - GZ 4 / 100 - 1450 kW
6
Easy Installation
The burner comes complete, including power dependent
equipment, and every component is clearly designed so that a
qualified heating engineer will have no problems with Installa-
tion, starting, and servicing.
Screws and gaskets for the burner installation are included. The
burner is electrically connected by a 7-pole plug according to
DIN 4791.
The burners are pre-tested and pre-set. The burner performance
is changed by adjusting the gas-flow throttle and the settings
(dimension B and air damper position).
In Germany, the heating engineer has to consider the existing
regulations of the DVGW (e.g. TRGI or TRF) and the local utility
companies.
General note as per DIN EN 676: This burner must be installed
in compliance with the valid specifications and must only be
operated in well aired rooms. The instructions before installing
and operating the burner must be observed.
The engineer must ensure that the heating room is suitably ven-
tilated with an air exchange rate of at least 100 m³/h. The gas
pipes must be installed and connected by an authorised heating
engineer. The weight of the gas compact ramps or assembly
must be supported by a suitable bracket.
The length of pipe between the gas ramps and the gas burner
must not exceed max. 800 mm (for GZ 2 and max. 500 mm for
GZ 3.0).
The VDE and EVU specifications must be observed when install-
ing the electrical connections.
The burner must be connected with a flexible cable. Do not in-
terchange the phase (live!) and neutral wires
As a result of the new master firing ordinance, some German
states stipulate the installation of thermally influenced gas stop
valves.
Fig. 4: Gas-Gebläsebrenner GZ 3
Instructions for using the burner
The burners GZ 2 – GZ 4 are basically suitable for use in com-
mercially available heating boilers (intermittent operation) for
heating residential buildings and for service water. Product de-
velopment and the test procedures have been geared to the
operating conditions of these systems.
The areas of application listed below make particular
requirements with special operating conditions for
the burner, so that MHG Heiztechnik reserves the right to is-
sue explicit approval in these cases:
ydark radiators
ybaking ovens
yannealing furnaces
ydrying chambers
yindustrial applications
MHG Heiztechnik should also be consulted for instal-
lations with above average firing chamber or tem-
perature loads.
In the case of rooms where the air must be expected
to be contaminated by halogenated hydrocarbons,
e.g. hairdressers, printers, chemical dry cleaners, laborato-
ries etc., the burners must only be operated if suitable
measures are taken to ensure that there is an adequate sup-
ply of uncontaminated combustion air.
Always consult MHG Heiztechnik if in any doubt.
The burners must not be operated in rooms with high
dust levels or high humidity (e.g. laundries). The heat-
ing room must be protected from frost and well aired.
Failure to comply with these instructions renders the
warranty null and void for any damage resulting from
one of these causes.
Leak test
A programme-controlled leak detector which checks the sole-
noids for leaks can be installed simply and retroactively. An ad-
ditional electrical connection at gas compact ramps is not nec-
essary. The leak lest provides additional security for the users of
gas firing systems. This feature is generally recommended, and
is a stipulated-requirement for burner outputs of 1200 kW and
more.

GZ 2 - GZ 4 / 100 - 1450 kW Installation-Operation-Maintenance
7
Rating of the gas ramps
Depending on the available gas flow pressure, a correspond-
ingly rated gas compact ramps or gas ramp system will be in-
stalled in the factory.
If the minimum connection pressure is not achieved under rated
heat load, a gas ramp system will have to be used with a larger
rated width; the gas pressure must be increased at the utility
company's gas transfer point, or the cross section of the supply
line between the gas transfer point and the gas ramp system
must be enlarged.
Before the gas fan burner starts up for the first time,
vent the gas pipe and then check the gas ramps for
leaks.
Gas compact ramp Rp 1“ and Rp 1¼“
Burner and gas ramps taken from the table on page 9 form a
complete unit , which has been subject to model certification.
The conventional arrangement of the gas ramps is designed as
an operational compact unit.
• Dirt pan with sieve and filter mat
• Pressure controller with admission pressure compensation
and zero closing
• Pressure detector, setting range 2.5 - 50 mbar, blocked when
liquefied gas is used
• Safety solenoid, opens and shuts quickly
• Two-stage solenoid, opens slowly, shuts quickly, adjustable
starting volume, stage 1 and 2
• Mounting flanges with measurement nipple
• Electrical connection with plug
Supply-pressure up to max. 360 mbar
{Comply with the Technical Rules for Gas Installations (DVGW-
TRGI) }
Fig. 5:

Installation-Operation-Maintenance GZ 2 - GZ 4 / 100 - 1450 kW
8
Gas compact ramp Rp 1½“ and Rp 2“
Burner and gas ramps taken from the table on page 9 form a
complete unit which has been subject to model certification.
Key parts are:
• Dirt pan with sieve and filter mat
• Safety solenoid, opens and shuts quickly, with setting for gas
volume stage 2
• Solenoid with setting for starting volume and gas volume
stage 1 , opens slowly and shuts quickly
• Pressure controller with admission pressure compensation
and zero closing
• Pressure detector, setting range 2.5 - 50 mbar
• Electrical connection with plug
Supply-pressure up to max. 360 mbar
Gas compact ramp DN 65 to DN 100
Burner and gas ramps taken from the table on page 9 form a
complete unit which has been subject to model certification.
Fig. 6:
Key parts are:
• Dirt pan with sieve and filter mat
• Safety solenoid, opens and shuts quickly, with setting for gas
volume stage 2
• Motor valve with setting for gas volume stage 2, opens slowly
and shuts quickly
• Pressure controller with admission pressure compensation
and zero closing
• Pressure detector, setting range 2.5 - 50 mbar
• Electrical connection with plug
Supply-pressure up to max. 200 mbar
Gas ramps GZ 3 liquid gas
• Pre-adjustment
Type Gas solenoid level 1
(partial quantity)
Gas solenoid level 2
(main quantity)
GZ 3.0 opened approx. ¾turn opened approx. ½turn
GZ 3.1 opened approx. 2¾
turn
opened approx. 1¾
turn
GZ 3.2 opened approx. 1½
turn
opened approx. 1¼
turn
GZ 3.3 opened approx. 1¾
turn
opened approx. 1½
turn
- Set pressure switch to approx. 20 mbar
- Open start gas quantity 1 turn
It is vital for the stated basic settings (see page 9) to
be met for liquid gas operation!
Setting of the switches in the motor valve connec-
tion box
Fig. 7:

GZ 2 - GZ 4 / 100 - 1450 kW Installation-Operation-Maintenance
9
Gas-burner and gas ramps assembly GZ 2 - GZ 4
Burner-
type Gas type
Burner
order
number
Suitable for boiler
performance
kW
Gas flow
pressure
mbar
Rated with
2)
DN
Order
number
Total weight
kg
GZ 2.1 Natural gas H (L,LL)
3)
Liquefied gas
-1001
-1008 100 - 200
28
26
GZ 2.2 Natural gas H (L,LL)
3)
Liquefied gas
-1002
-1018 180 - 300
28
26
GZ 3.0 Natural gas H (L,LL)
3)
Liquefied gas
-3085
2)
260 - 315 20 50 Rp 1¼“
1)
50
GZ 3.1 Natural gas H (L,LL)
3)
Liquefied gas
-3175
2)
315 - 500 25-50 50 Rp 1½“ -3044 67
GZ 3.2 Natural gas H (L,LL)
3)
Liquefied gas
-3275
2)
450 - 650 25-50 50 Rp 2“ -3054 73
GZ 3.3 Natural gas H (L,LL)
3)
Liquefied gas
-3305
2)
550 - 810 25-50 50 Rp 2“ -3054 74
GZ 4.1 Natural gas H (L,LL)
3)
Liquefied gas
-4105
-4108 700 - 1020 35-50 50 DN 65 -4065 173
GZ 4.2 Natural gas H (L,LL)
3)
Liquefied gas
-4205
-4208 900 -1450 25-50 50 DN 80 -4080 201
1)
included in burner order number
2)
It is vital for the stated basic settings (see page 8) to be met for liquid gas operation!
Table of basic settings and dimensions GZ 2 - GZ 4
Gas flow rate Air pressure Nozzle pressure
Burner-
type Gas type
Suitable for boiler
performance
kW
Stage 1
m3 /h
Stage 2
m3 /h
Dim.
A
mm
Dim.
B
mm
Dim.
D
mm
Stage 1
mbar
Stage 2
mbar
Stage 1
mbar
Stage 2
mbar
Air
supply
nozzle
GZ 2.1 Natural gas H (L,LL)
3)
Liquefied gas
100 - 200 10
4
14
5,5 18 50 57 95 2 3
7
8
6
13
10
16
9,5
7,5
GZ 2.2 Natural gas H (L,LL)
3)
Liquefied gas
180 - 300 16
6
23
9 18 70 110 2,5 5 7
5
11
9
20 9,5
GZ 3.0 Natural gas H (L,LL)
3)
Liquefied gas
260 - 315 19
7,6
32
13,8 23 65 75 110 3,4 1,2
7,2
7
5,5
2,2
11,7
10 0
GZ 3.1 Natural gas H (L,LL)
3)
Liquefied gas
315 - 500 26
9,5
43,5
15
20
25
88
135
130
126
3,5
2
11,5
6
4,8
3,5
12
9
7,5
1,5
GZ 3.2 Natural gas H (L,LL)
3)
Liquefied gas
450 - 650 39
14
65
25
20
27
118
120 145 5,5 1,5
11,5
9
4,2
2,5
11
9,5
7,5
2,5
GZ 3.3 Natural gas H (L,LL)
3)
Liquefied gas
550 - 810 53
16
75
28 27 117 120 145 3,5 2
9
10
6
3
13
11,5
8
3,5
GZ 4.1 Natural gas H (L,LL)
3)
Liquefied gas
700 - 1020 58
24,8
91
33,1 33 125 130 175 9 13,5
17
18,5
6,5
12
14
16,5
2
1,5
GZ 4.2 Natural gas H (L,LL)
3)
Liquefied gas
900 -1450 85
27,9
125
46,5 33 130 141 175 10,5 7,5
17,5
17 5 9 11
2
1,5
3)
For operation with natural gas (L, LL), only the gas quantity is increased. The output-related basic setting does not have to be changed. Power reduc-
tion for natural gas (L) approx. 15%, for natural gas (LL) approx. 30%

Installation-Operation-Maintenance GZ 2 - GZ 4 / 100 - 1450 kW
10
Adjusting the burner
Every burner is pre-tested and pre-set. The basic adjustment is
shown in the table above (reference values valid for the gas
type indicated).
The burner must be adjusted and started by a qualified heating
engineer.
Adjusting the gas flow range:
• gas pressure (nozzle pressure): at the adjusting screw of the
gas pressure controller 2
increased gas pressure
decreased gas pressure
• gas volume stage 2 - at the adjustment for valve 3
less gas
more gas
• gas volume stage 1 - at the adjusting wheel of solenoid stage
1 4
less gas
more gas
• for gas ramp systems DN 65/80/ 100 at the motor valve 4
(Johnson Controls see illustration on the left)
• starting gas volume - at the adjusting screw of valve 1 1
opening quickly
opening slowly
• The gas pressure detector is to be set to the flow pressure at
which perfect function of the gas burner is still possible.
There are three possible ways of adjusting the combustion air:
a. by adjusting the air supply nozzle according to burner out-
put and local conditions:
• position 0 - 5 (0 -1) for natural draught boilers
• position 6 - 9.5 (2 - 4) for counter-pressure boilers
b. by adjusting the baffle plate in the burner tube (see fable
with basic settings); this adjusts the air velocity in the
combustion head together with the flame shape to the
combustion chamber conditions
c. by adjusting the air damper for the 1st and 2nd stage us-
ing the (blue) cam controller for stage 1 and (orange) for
stage 2; the air volume is reduced to the left and increased
to the right. An inadequate air volume in stage 1 is ad-
justed as follows:
• adjust the (blue) cam controller up-wards (more air)
• briefly switch over to stage 2 at boiler thermostat 2. After
switching back, the servomotor turns back into the required
position.
When the air volume is too large in stage 1 or too small in stage
2, the corresponding cam controller must be adjusted. To re-
duce an excessive air volume, the (orange) cam controller must
be adjusted accordingly and the servomotor is closed by switch-
ing the controller for the second stage or by disconnecting the
green 4-pole plug, then start up again in the operation setting.
The switching point for the second solenoid (stage 2) or motor
valve can be changed using the long black cam controller.
When switching the burner off for regular servicing or to elimi-
nate faults, the air damper can be closed using the (short black)
cam controller of the servomotor. It is advisable to measure the
air pressure before the baffle plate to check the setting (see ta-
ble values for air pressure). The measuring point is located next
to the gas supply pipe on the flange cover.
Fig. 8:

GZ 2 - GZ 4 / 100 - 1450 kW Installation-Operation-Maintenance
11
Position air guidance device GZ 3 and GZ 4
Fig. 9:
Air inlet nozzle
Fig. 10: Adjusting the air inlet nozzle for GZ 2 / GZ 3
The air inlet nozzle can be adjusted once the burner has been
opened. Both screws on the air inlet nozzle should be loosened
slightly, and must be screwed tight again after the adjustment
has been made.
Fig. 11: Adjusting the air inlet nozzle for GZ 4
The air inlet nozzle can be adjusted once the burner has been
switched off and the suction silencer has been hinged away.
Both screws of the air inlet nozzle should be loosened slightly,
and must be screwed tight again after the adjustment has been
made.

Installation-Operation-Maintenance GZ 2 - GZ 4 / 100 - 1450 kW
12
Settings
Fig. 12:
Spark electrode setting
Fig. 13:
Installation position Multiblock
All gas Multiblocks must only be installed as shown
below
Installation in the grey area is not permitted.
Fig. 14:
GZ 4 liquefied gas
GZ 4 natural gas
GZ 2
GZ 3

GZ 2 - GZ 4 / 100 - 1450 kW Installation-Operation-Maintenance
13
Fault diagnosis
Flame monitoring makes use of the conductivity and rectifier
effect of the flame, by means of an ionisation electrode.
The flame signal amplifier only reacts to the DC component
of the flame signal.
A short circuit between ionisation electrode and earth
causes a fault cutout.
MMI 810.1 mains voltage
UN = AC 230 V
necessary sensor current for reliable
operation > 5 µA
Fig. 15: Legend measuring circuit
FE Ionisation electrode
M Multimeter
Fig. 16: Position ionisation electrode GZ 2
Ionisation current in operation: GZ 2: 15 - 22 µA
Fault diagnosis MMI 810
Fault Remedy
Burner does not start,
program display re-
mains the same
• Faulty electric lead
• Thermostat or gas switch
"OFF""
Burner does not start,
program display turns
constantly
• Air pressure switch not in idle
position (working contact must
be open)
• Connection terminal 1 –terminal
9 interrupted
• Operating voltage < 180V
Automatic unit shows a
fault just after starting
pre-venting (line in
blue box)
• Air pressure switch contact does
not close
• No load at terminal 5
• Flame signal
Automatic unit shows a
fault during pre-
venting (blue area)
• Air pressure switch contact
opens
• Flame signal
Automatic unit shows a
fault during the safety
period (yellow area)
• No flame formed (faulty ignition,
valve does not open, etc.)
• No or weak flame signal (flame
does not hold, poor insulation of
flame sensor, burner not cor-
rectly connected to earth con-
ductor)
Automatic unit shows a
fault during operation
setting (red or green
area)
• Flame breaks off
• Air pressure switch contact
opens
• Flame signal too weak

Installation-Operation-Maintenance GZ 2 - GZ 4 / 100 - 1450 kW
14
Fault diagnosis TMG 740-3 and TMG 740-2
Fault Remedy
Burner does not start,
program display re-
mains the same
• Faulty electric lead
• Thermostat or gas switch
"OFF""
Burner does not start,
program display turns
constantly
• Air pressure switch defect or not
in idle position (working contact
must be open)
Automatic unit shows a
fault just after starting
pre-venting (line in
blue box)
• Air pressure switch contact does
not close
• Flame signal
Automatic unit shows a
fault during pre-
venting (blue area)
• Air pressure switch contact
opens
• Flame signal
Automatic unit shows a
fault during the safety
period (yellow area)
• No flame formed (faulty ignition,
valve does not open, etc.)
• No or weak flame signal (flame
does not hold, poor insulation of
flame sensor, burner not cor-
rectly connected to earth con-
ductor)
Automatic unit shows a
fault during operation
setting (red or green
area)
• Flame breaks off
• Air pressure switch contact o-
pens
• Flame signal too weak

GZ 2 - GZ 4 / 100 - 1450 kW Installation-Operation-Maintenance
15
Troubleshooting
Check general operating status. Are the stated values met?
Störung Ursache Behebung
Burner does not work
Check main switch, fuse, boiler thermostat
Check voltage (neutral and live wires)
Check leak detector
Check gas pre-pressure
Check gas pressure detector (setting, function)
Replace firing sequence controller
Burner Starts
Gas pressure and gas shown
No ignition spark
Check ignition transformer, ignition cable and
spark electrode setting
Replace firing sequence controller
Burner works
Gas pressure shown
Spark visible
No flame
Air in the gas pipe
Flame detector could be exposed to another
source of light
Burner works
Gas pressure shown
Spark visible
Flame OK
No ionisation current
(GZ 2 + GZ 4)
No infrared display (GZ 3)
Fault cutout
Check connection of neutral and live wires
Check gas flow pressure (fluctuating pressure
gauge display = gas pipe too small or pressure
controller defect
Set infrared flicker detector (IRD) (GZ 2 + GZ 4)
to 7, check IRD's Position, replace IRD (GZ 3)
Replace firing sequence controller
Burner does not start up,
program display stays the
same
Faulty electric lead
Thermostat or gas pressure switch off
Check electric leads
Replace thermostat or gas pressure switch
Burner does not start up,
program display turns con-
stantly
Air pressure switch defect or not in idle position
(contact must be open)
Replace air pressure switch
Burner starts up, automatic
unit shows fault just after
starting pre-venting
Air pressure switch contact does not close Check wiring for air pressure switch
Replace air pressure switch

Installation-Operation-Maintenance GZ 2 - GZ 4 / 100 - 1450 kW
16
Fault Cause Remedy
Burner starts up,
automatic device shows fault
during pre-venting
Air pressure switch contact opens
Flame signal
Check pulse lead
Check ionisation current [fault current?]
(GZ 2 + GZ 4)
check infrared flicker detector IRD (GZ 3)
Burner starts up,
automatic device shows fault
during safety period
No flame formed (lacking ignition, valve does
not open, etc.)
No or weak ionisation current
(GZ 2 + GZ 4)
No or weak flame signal (GZ 3)
[Flame does not hold, poor insulation of flame
sensor, burner not correctly connected to earth
conductor]
Check pulse lead
Check ionisation current [fault current?]
(GZ 2 + GZ 4)
check infrared flicker detector IRD (GZ 3)
Burner starts up,
automatic device shows fault
during operation setting
Flame breaks off
Air pressure switch contact opens
Ionisation current too low (GZ 2 + GZ 4)
Flame signal too low (GZ 3)
Check pulse lead
Check ionisation current [fault current?]
(GZ 2 + GZ 4)
check infrared flicker detector IRD (GZ 3)
Safety warning!
The mains voltage must be switched off
and the main stop valve in the gas pipe closed
whenever any kind of work is being performed
to the burner and switchboard

GZ 2 - GZ 4 / 100 - 1450 kW Installation-Operation-Maintenance
17
Burner dimensions
Fig. 17:
Burner
type Type of gas Gas ramp
system
Dim.
L1
approx.
Dim.
L2
approx.
Dim.
L3
approx.
Dim.
L4
Dim.
L5
approx.
Dim.
D1
ø
Dim.
D2
ø
Dim.
H1
Dim.
H2
Dim.
H3
Dim.
B
GZ 2.1 Natural gas Rp 1“ 150 230 240 80 570 115 115 240 355 295 305
GZ 2.1 Liquefied gas Rp 1“ 150 230 240 80 570 115 115 240 355 295 305
GZ 2.2 Natural gas Rp 1¼“ 180 230 240 80 600 115 130 240 355 295 305
GZ 2.2 Liquefied gas Rp 1“ 180 230 240 80 600 115 130 240 355 295 305
GZ 3.0 Natural gas Rp 1¼“ 200 350 260 130 830 140 140 350 490 380 375
GZ 3.1 Natural gas Rp 1½“ 265 350 525 130 850 140 175 320 490 380 386
GZ 3.1 Natural gas Rp 2“ 265 350 570 130 850 140 175 320 490 380 386
GZ 3.2 Natural gas Rp 2“ 270 350 570 130 850 152 200 320 490 380 386
GZ 3.3 Natural gas Rp 2“ 270 470 570 130 970 152 200 320 490 380 386
GZ 3.3 Natural gas DN 65 270 470 1580 180 970 152 200 370 490 380 386
GZ 4.1 Natural gas Rp 2“ 430 590 1230 210 1380 186 230 285 650 515 470
GZ 4.1 Natural gas DN 65 430 590 1650 210 1380 186 230 285 650 515 470
GZ 4.1 Natural gas DN 80 430 590 2150 210 1380 186 230 285 650 515 470
GZ 4.2 Natural gas DN 65 430 590 1650 210 1380 186 280 285 650 515 470
GZ 4.2 Natural gas DN 80 430 590 2150 210 1380 186 280 285 650 515 470
GZ 2.1 - GZ 3.3
GZ 4.1 - GZ 4.2

Installation-Operation-Maintenance GZ 2 - GZ 4 / 100 - 1450 kW
18
Connections
Burner
type Motor voltage Motor output Connected wattage
GZ 2 230 V WS 50 Hz 0,25 kW 0,37 kW, ca. 2 A
GZ 3.0 230 V WS 50 Hz 0,45 kW 0,7 kW, ca. 3,2 A
GZ 3.1 400 V DS 50 Hz 1,1 kW 1,4 kW, ca. 3 A
GZ 3.2 400 V DS 50 Hz 1,1 kW 1,4 kW, ca. 3 A
GZ 3.3 400 V DS 50 Hz 1,1 kW 1,4 kW, ca. 3 A
GZ 4 400 V DS 50 Hz 3,0 kW 3,3 kW, ca. 6 A
Boiler connections
Electric supply diagram
Assembly with silencer hood for GZ 3
and GZ 4
When a silencer hood is fitted, the pipe double nipple may have
to be lengthened to a size of 200 mm.
The pipe length between gas ramps and burner
should be as short possible. For gas burners GZ 3 and
GZ 4, the max. pipe length is 800 mm. A bracket is required
to take the weight of the gas ramps.
The dimension H must be checked before erecting boilers with-
out boiler foundations.
Fig. 18: Assembly with silencer hood for GZ 3 and GZ 4
Type D1 D2 M
GZ 2.1 130 160 ÷ 180 8/10
GZ 2.2 140 160 ÷ 180 8/10
GZ 3.0/1 150 180 ÷ 205 10
GZ 3.2/3 162 220 ÷ 240 10
GZ 4 195 246 ÷ 276 12

GZ 2 - GZ 4 / 100 - 1450 kW Installation-Operation-Maintenance
19
Circuit diagramm GZ 2
Fig. 19:
Item b2 b3 b4 b5 b6 b8 IS k1 m1 m2 m3 s1 s2 u1 u2
Indication On-off-Switch Safety thermostat On-off-thermostat On-off-thermostat Gas pressure switch Air pressure switch Ionization Condenser Motor with condenser Ignition transformer Servomotor Solenoid valve , two-stage
(
stage 1 and 2)
Safety solenoid valve Gas burner automatic safety
l
Leakage tester Observe local and VDE-regulations. Connections to earth potential being executed carefully.
Also when using the leak check
Caution: do not confuse phase and Mp.
Multibloc
Working hours 2
Working hours 1
Failure

Installation-Operation-Maintenance GZ 2 - GZ 4 / 100 - 1450 kW
20
Circuit diagramm GZ 3.0
Item b2 b3 b4 b5 b6 b8 IS k1 m1 m2 m3 s1 s2 u1 u2
Indication On-off-Switch Safety thermostat On-off-thermostat On-off-thermostat Gas pressure switch Air pressure switch Infra-red flicker detector Condenser Motor with condenser Ignition transformer Servomotor Solenoid valve , two-stage
(
stage 1 and 2)
Safety solenoid valve Gas burner automatic safety
c
ontrol
Leakage tester Observe local and VDE-regulations. Connections to earth potential being executed carefully.
Fig. 20:
Also when using the leak check Caution:
do not confuse phase and Mp.
Multibloc
Working hours 2
Working hours 1
Failure