Riello RX 70 S/PV Quick start guide

2903350 (1) - 10/2007
Installation, use and maintenance instructions
Instrucciones de instalación, uso y mantenimiento
Pre-mixed gas burner
Quemador de gas pre-mezclado
CÓDIGO - CODE MODEL - MODELO TYPE - TIPO
3790100 RX 70 S/PV 901 T
GB
E
Progressive two-stage or modulating operation
Funcionamiento a dos llamas progresivo o modulante

3350
1GB
INDEX
1. BURNER DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1 Burner equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. TECHNICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2 Gas categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3 Overall dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.4 Firing rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Boiler plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Boiler fixing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.3 Probe and electrode positioning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.4 Fuel supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.5 Electrical wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.6 Fan adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4. BURNER OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.1 Adjustment before first firing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2 Burner start-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.3 Burner adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.4 Combustion head. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.5 Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.6 Operation programme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.6.1 Normal operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.6.2 Lockout due to firing failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.6.3 Lockout due to detection of flame or flame simulation during pre-purging . . . . . . . . . . . . . . . . 13
4.7 Recycle function if flame goes out during operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.8 Restart function following firing failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.9 Checking motor rpm during pre-purging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.10 Post-purging function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.11 Logging of burner operating parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.12 Function setting procedure using reset button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.13 Control box reset (using built-in button) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.14 Control box reset (via remote connection) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5. MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1 Visual diagnostics control box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6. FAULTS / SOLUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.1 Start-up problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.2 Operating faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7. WARNINGS AND SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7.1 Burner identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7.2 Basic safety measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3350
2GB
1. BURNER DESCRIPTION
Gas burner with two-stage progressive or modulating operation.
1.1 BURNER EQUIPMENT
Insulating gasket . . . . . . . . . . . . . . . No. 1 Screws and nuts for boiler fixing flange . . . . . . . No. 4
Remote reset connection . . . . . . . . . No. 1 7-pin plug. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . No. 1
4 pin plug . . . . . . . . . . . . . . . . . . . . No. 1 Gas valve fitting + screws . . . . . . . . . . . . . . . . . No. 1
Spare parts list . . . . . . . . . . . . . . . . No. 1 Instructions manual . . . . . . . . . . . . . . . . . . . . . . No. 1
1.2 ACCESSORIES
DIAGNOSTIC SOFTWARE KIT
A special kit is available that, by an optical link to a PC, shows the burner life together with operating hours,
type and number of lockout, serial number and no. of motor rpm's.
To display the diagnostic, proceed as follows:
³Connect the kit supplied separately to the appropriate socket on the control box.
The information is read after the software program in the kit is booted.
REMOTE RESET KIT
The burner is fitted with a remote reset kit (RS)consisting of a connection to which a button can be con-
nected up to a distance of 20 meters.
For the installation, remove the protection block installed in the factory and install the block that is supplied
with the burner (see wiring diagram on page 8).
LPG KIT
There is a special kit available that, when mounted on the gas valve, enables burners suitable to run on
natural gas, to burn LPG. Refer to the instructions supplied with the “LPG kit” for installation. The kit must
be installed in conformity with laws and local regulations.
2
1– Reset button with lockout warning
2– Control box
3–Gasvalve
4– Air/gas mixer in intake circuit
5– Flange
6– Motor
³CE marking according to Gas Directive 90/396/EEC; CE-0085BR0101
The burner conforms with the Directives: EMC 89/336/EEC, Low Voltage 73/23/EEC, according to EN 676.
³Gas train conforms with Gas Directive 90/396/EEC.
³The burner has been tested to conform with the Directives EN60335 / EN50165.
To comply with the above-mentioned requirements it is necessary for the burner to be protected by a
hood or by the boiler door Removal of this protection must only be possible with the aid of a tool.
Fig. 1
D7371
6
7–4polesocket
8– Manifold
9– Combustion head with metal mesh
10 –Electrode
11 – Probe
17
8
4 3
9
5
11
10

3350
3GB
2. TECHNICAL DATA
2.1 TECHNICAL DATA
2.2 GAS CATEGORIES
2.3 OVERALL DIMENSIONS
Model RX 70 S/PV
Thermal power 9 - 70 kW - 7,700 - 60,200 Kcal/h
Natural gas -
(Family 2)
G20 Net calorific value: 9.45 kWh/Sm3 = 8,100 kcal/Sm3- Pressure 10 - 30 mbar
G25 Net calorific value: 8.125 kWh/Sm3 = 7,000 kcal/Sm3- Pressure 10 - 30 mbar
LPG - (Family 3) G31 Net calorific value: 24.44 kWh/Sm3 = 21,000 kcal/Sm3- Pressure 10 - 30 mbar
Electrical supply Single-phase, ~50/60Hz 220/230 V ±10%
Motor max. 6000 rpm - 50/60Hz
Ignition transformer Primary 230V - 0.2A – Secondary 8 kV - 12 mA
(1) Reference conditions:
Air temperature 20°C - Gas temperature 15°C - Barometric pressure 1013 mbar - Altitude 0 m a.s.l.
COUNTRY
AT - CH - CZ - DK
EE - ES - FI - GB
GR - IE - IT - LT
LV - NO - PT - SE
BE - DE - DK - ES
FI - FR - GB - GR
IE - IT - LU - NO
PT - SE
AT - BE - CH - CZ
DE - ES - FR - GB
GR - IE - IT - PT
FR DE BE LU - PL
GAS CATEGORY I2H I2R I3P I2Er I2ELL I2E(R)B I2E
GAS PRESSURE 20mbar 20/25mbar 29mbar 20/25mbar 20mbar 20/25mbar 20mbar
292
275
67
110
296
511
D7372

3350
4GB
2.4 FIRING RATE
TEST BOILERS
The firing rates were set in relation to special test boilers, according to EN 676 regulations.
COMMERCIAL BOILERS
The burner-boiler matching is assured if the boiler conforms to EN 303 and the combustion chamber
dimensions are similar to those shown in the diagram EN 676.
For applications where the boiler does not conform to EN 303, or where the combustion chamber is much
smaller than the dimensions given in EN 676, please consult the manufacturers.
kW
Thermal power
Pressure in combustion
chamber – mbar
kcal/h
D7199
Firing rate G20 Firing rate G25
kW
Thermal power
Pressure in combustion
chamber – mbar
kcal/h
Firing rate G31 Firing rate G30
D7187

3350
5GB
CORRELATION BETWEEN GAS PRESSURE / OUTPUT AND N° MOTOR RPMs/min. / OUTPUT
Thermal power – kW
D7200
No. motor rpm's/min
Gas valve outlet pressure - mbar
Pressure in combustion chamber = 0 mbar
G20/G25
n°rpm's/min.
Pressure-mbar
Thermal power – kW
D7188
No. motor rpm's/min
Gas valve outlet pressure - mbar
Pressure in combustion chamber = 0 mbar
G30/G31
n°rpm's/min.
Pressure-mbar

3350
6GB
3. INSTALLATION
THE BURNER MUST BE INSTALLED IN CONFORMITY WITH LEGISLATION AND LOCAL STANDARDS.
3.1 BOILER PLATE, (see fig. 2)
Make holes in the plate shutting off the combustion chamber as il-
lustrated in fig. 2. The position of the threaded holes may be
marked using the insulating gasket supplied with the burner.
3.2 BOILER FIXING, (see fig. 3)
Carry out the following for installation:
³Fasten the burner (1) to the
boiler's door (2) by means of the
four screws and (if necessary) the
nuts supplied, placing the insulat-
ing gasket (3) between the two.
3.3 PROBE AND ELECTRODE POSITIONING, (see fig. 4)
IMPORTANT
Do not turn the electrode (1): position it as illus-
trated in the figure.
Placing the electrode (1) near the ionization probe
(2) may result in the control box amplifier being
damaged.
140
160
150
11
45°
118
Fig. 2
D7582
D7373
2
1
Fig. 3
3
67mm
4 mm
15mm
D7158
1
2
Fig. 4

3350
7GB
3.4 FUEL SUPPLY
The burners are teamed with one-piece pneumatic proportioning gas valves, via which the amount of gas
delivered, and hence the output produced, can be modulated.
A signal reporting pressure detected in the air circuit is carried to the pneumatic gas valve, which delivers an
amount of gas in proportion to the airflow produced by the fan.
The gas train, in order to render the dimensions efficent is assembled directly onto the burner body.
GAS TRAIN ASSEMBLY
D7375
D7155 D7380
Note: With the valve/manifold connection, accidental blocking of the intake can be compensated by
reducing the amount of gas delivered.
Air/gas mixer
Gas and combustive air are mixed in-
side the purging circuit (mixer), start-
ing from the intake inlet.
Through the gas train, fuel is intro-
duced into the intake air current and
optimal mixing commences with the
aid of a mixer.
Gas valve
Valve model Honeywell VK4125V 10054
Mixer model Honeywell 45.900.44-001
Gas line connection ½" inlet
Working temperature -15°C/70°C
Max. working pressure 30 mbar
Min. working pressure 15 mbar
Max. inlet pressure 60 mbar
Valve class B + B
Electrical supply 220-240 V
Protection level IP 40 according to IEC 529
Air/gas mixer
in the suction circuit
Gas supply
Gas pressure upline
test point (P1)
Gas pressure downline
test point (P2)
Flange Gas valve
Maximum gas flow
Minimum gas flow adjustment
on the stabiliser (V2)
D7376
Gas compensation pipe
adjustment (V1)

3350
8GB
3.5 ELECTRICAL WIRING
XM3
X7 X4
T6A
TR
h1 SB
NPE L
TSTL
+15
0
OUT
1ST
2ST
DOWN
N
PE
F
GND
XM5
B4 S3 T2 T1 N L1
V
PE
MG 557- P
M
S2
S1
R
TB
ETB
B
C
A
N
L2
G
SO
CN1
N+
RPM
M
PE
TB
1
2
N
N
BN BU
RD WH BK
BRUSHLESS
DRIVER
T8 B5
T6
T7
XP4
UP
KEY TO LAY-OUT
BN –Brown
BK –Black
BU –Blue
RD –Red
WH – White
CN1 – Probe connector
E– Electrode
H1 – Hour counter
M– Motor
PS – Remote reset button
D7590
WARNING:
³Do not swap neutral and phase over, follow the diagram shown carefully and carry out a good earth connection.
³The cross section of the conductors must be at least 1 mm2. (Unless requested otherwise by local standards and
legislation).
³The electrical wiring carried out by the installer must comply with the rules in force in the country.
THE BE DONE
BY INSTALLER
CARRIED OUT
IN THE FACTORY
TESTING
³Check the burner goes off by opening the thermostats.
³Check that the burner has locked out during operation
by opening the connector (CN1) inserted in the probe's
red wire, located outside the control box.
SB – Lock-out indicator
SO – Ionisation probe
TB – Burner earth
TL – Limit thermostat
TR – 2nd stage thermostat
TS – Safety thermostat
T6A –Fuse
V– Valve
X4 – 4-pin plug
X7 – 4-pin plug
XP4 – 4-pole socket
XM.. – DRIVER plugs
~50/60Hz 220/230V

3350
9GB
3.6 FAN ADJUSTMENT, (see fig. 5)
Modulation is based on variable-speed technology. Combustive air delivery can be adjusted by varying the
motor's speed (rpm). The proportioning gas train, depending on the pressure detected in the purging cir-
cuit, delivers the right amount of fuel. Hence the output delivered is adjusted by varying the motor's speed
of rotation. The motor speed can be adjusted by regulating three “Trimmers”.
4. BURNER OPERATION
4.1 ADJUSTMENT BEFORE FIRST FIRING
The following adjustments are to be made:
- Open the manual valves located upline from the gas train.
- Bleed the air from the gas pipes using the screw on the socket START.
- Connect the diagnostic software kit to the control box: via this kit, you can view the motor's rpm.
- Check the settings chosen with the trimmers located on the control box (fig. 5).
4.2 BURNER START-UP
Close the thermostat and switch on the burner's power.
The burner starts in pre-purging mode at top speed.
Speed subsequently decreases to the START value and the burner fires.
If however the fan starts but no flame has appeared by the end of the safety period, the control box allows the
start-up programme to be repeated: up to 3 attempts are made.
If there is no firing by the fourth attempt, the burner goes into lockout.
Reset and wait for a new start-up attempt.
If the burner still does not fire, the problem may be that gas is not reaching the combustion head within the
3-second safety time.
Turn screw V1 on the gas valve mixer anticlockwise slightly.
Once the burner has fired, proceed with global calibration operations.
D7238
D7237 3-pin terminals
MAX: maximum output
START: start-up output
power
Terminals for connecting
output regulator
Fig. 5
power adjustment
MIN: minimum output
power adjustment
Trimmers

3350
10 GB
4.3 BURNER ADJUSTMENT
To achieve optimal burner adjustment, the flue gases produced by combustion must be analysed as they leave
the bouiler. In conformity with Efficiency Directive 92/42/EEC, the burner must be applied to the boiler, adjusted
and tested in compliance with the instruction manual of the generator in question, including checking of CO and
CO2concentration in flue gases and their temperature
Check in this order:
- maximum output power; - minimum output power; - start-up output power.
The maximum output power should coincide with that required by the boiler used. To increase or decrease its
value, adjust trimmer MAX on the control box (fig. 5).
Measure the gas delivery on the contactor to precisely establish the burnt output.
Using a smoke analyser measure to the value of the CO2 or the O2 in order to optimise the burner calibration.
The correct values are: CO28,5-9% or O25-5.5%.
To correct these values act on thee gas valve in the following way:
- To increase the gas delivery and the CO2: turn the V1 screw anticlockwise (unscrew).
- To reduce the gas delivery and the CO2: turn the V1 screw clockwise (tighten).
The minimum output power should coincide with that required by the boiler used. To increase or decrease its
value, adjust trimmer MIN on the control box (fig. 5).
Measure the gas delivery on the contactor to precisely establish the burnt output.
Using a smoke analyser, measure the value of the CO 2 or the O2 in order to optimise the burner calibration.
The correct values are: CO28,5-9% or O25-5.5%.
To correct these values act on the gas valve in the following way:
- To increase the gas delivery and the CO2: turn the screw V2 in an clockwise direction (tighten).
- To reduce the gas delivery and the CO2: turn the screw V2 in a anticlockwise direction (unscrew).
To increase or decrease its value, adjust trimmer START on the control box (fig. 5).
4.4 COMBUSTION HEAD
The combustion head comprises a highly heat resistant cylin-
der whose surface features numerous holes, encased in a
metal "mesh".
The air-gas mixture is pushed inside the cylinder and out of
the head through the holes in the perimeter. Combustion
starts when the air-gas mixture is ignited by a spark generat-
ed by the electrode.
The metal "mesh" is the combustion head's most essential element since it improves burner performance
considerably.
The flame developed on the surface of the head is perfectly retained and adheres to the mesh when oper-
ating at the maximum setting. This allows modulating ratios as high as 6:1, avoiding the danger of flashback
when modulating is at its minimum.
The flame features an extremely compact geometry, meaning that there is no risk of contact between the
flame and parts of the boiler, consequently eliminating the possible problem of poor combustion.
The flame's structure means that smaller combustion chambers can be developed, designed to exploit this
particular feature.
NOTE: The START adjustment range goes from notch 0 to notch 5 (4,500 rpm), if the latter is
exceeded, the burner does not start.

3350
11 GB
4.5 EMISSIONS
The burners' emission values (according
to EN 676) prove much lower than the
limits laid down by the strictest stand-
ards.
The flame's distribution and its spread
over a large surface means that the burn-
er manages to limit the formation of ther-
mal NOx, the main causes of pollutant
emission.
IONISATION CURRENT
The minimum current necessary for the control
box operation is 5 µA. The burner gives a
much higher current, meaning that checking is
not usually required. Should you want to meas-
ure the ionization current anyway, you must
open the connector (CN1) (see wiring diagram
page 8) inserted in the red wire and insert a
microammeter.
mg/kWh
NOx
CO
NOx
CO
CLASS LIMIT 3 = 80 mg/kWh
70
60
50
40
30
20
10
0
Modulation
minimum 7 kW
Modulation
maximum 35 kW
Probe
Connectors
Control box
D7256

3350
12 GB
4.6 OPERATING PROGRAMME
4.6.1 NORMAL OPERATION
t 3
t 4i
t s
t 4L
T
L
M
I
V
SO
LED
LED
P
M
.
t 1
SO
t
2
t 3b
t 3a
KEY TO LAY-OUT
I– Ignition transformer
LED – Reset button LED indicating operating
status
M– Fan motor
SO – Ionisation probe
TL – Limit thermostat
V–Gasvalve
t1 Standby time pending an input signal to control box:
reaction time, the control box stands still for the time t1.t3I Flame or flame simulation detected during pre-purging: immediate lockout.
t1I
Flame or flame simulation detected before demand for
heat:
if the presence of light lasts for the t1l time, a lockout fol-
lows.
ts
Safety time:
if no flame is detected by the end of time ts the cycle
(start-up) is repeated and lockout occurs after 3
attempts to restart.
t2 Standby time after a request for heat:
the control box stays still for the t2 time. t4i Transformer ignition time: total ignition time.
t2I
Flame or flame simulation detected during standby time:
lockout occurs if flame or flame simulation persists for
time t2l.
t4I
Flame loss in operation:
valve drop maximum reaction time, lockout occurs after
3 recycle attempts.
t3 Pre-purging time:
start of the fan motor. t6
Post-purging time:
additional purging time on the opening of the heat limit
thermostat (TL).
t3a Purging check at maximum rpm from 12th to 20th sec-
ond of pre-purging. t6I
Flame or flame simulation detected during post-purging:
lockout occurs if flame or flame simulation persists for
time t6l.
t3b Purging check at START rpm from 35th to 40th second
of pre-purging.
D7252
MV = still
Flame loss during operation (Recycle max 3 attempts)
Lockout
Red (LED lights)
Green (LED lights)
No signal needs to be received
Purging motor at max. rpm
Purging motor at START rpm
Green
Green
Red
OPERATING TIMES
Time expressed in seconds
t1 t1I t2 t2l t3 t3a t3b t3l ts t4i t4l t6 t6l
max max -max ---max --max max max
1303304085133136030
(t3b)

3350
13 GB
4.6.2 LOCKOUT DUE TO FIRING FAILURE
LOCKOUT TYPES AND TRIGGERING TIMES IN CASE OF BURNER MALFUNCTION
DESCRIPTION OF THE FAULT TYPES LOCKOUT
Flame detected when burner is started or switched off After max. 30 seconds (after TL)
Flame detected during pre-purging Within 1 second
Flame detected during post-purging After max. 30 seconds
No ignition at the end of the safety time “ts” After a maximum of 3 repetitions within one second
Flame goes out during operation After a maximum of 3 repetitions within one second
Incorrect fan motor speed (rpm) Within “t3a” and/or “t3b”
ts
TL
M
I
V
SO
LED
P
Mt4i
t2t1t3
.
t3b
t3a
4.6.3 LOCKOUT DUE TO DETECTION OF FLAME
OR FLAME SIMULATION DURING PRE-
PURGING
D7253
Red
Red
Lockout
D7254
KEY TO LAY-OUT
I– Ignition transformer
LED – Reset button LED indicating operating
status
M– Fan motor
SO – Ionisation probe
TL – Limit thermostat
V–Gasvalve
Red (LED lights)
Green (LED lights)
Purging motor at max. rpm
Purging motor at START rpm
Green
Green
OPERATING TIMES
Time expressed in seconds
t1 t1I t2 t2l t3 t3a t3b t3l ts t4i t4l t6 t6l
max max -max --- max -- max max max
1303304085133136030
Lockout at 4th
restart
Red (LED lights)
Green (LED lights)
Purging motor at max. rpm
(t3b)

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14 GB
4.7 RECYCLE FUNCTION IF FLAME GOES OUT DURING OPERATION
The control box allows a recycle, i.e. complete repetition of the start-up programme, making up to
3 attempts, in the event the flame goes out during operation.
If the flame goes out again, this will cause the burner to lock out. If there is a new demand for heat during
the recycle, the 3 attempts are reset when the limit thermostat (TL) switches.
4.8 RESTART FUNCTION FOLLOWING FIRING FAILURE
The control box allows the start-up programme to be repeated, making up to 3 attempts, if no flame is
formed by the end of the safety time.
If the flame still fails to appear after the fourth ignition attempt, the burner locks out at the end of the safety
time.
4.9 CHECKING MOTOR RPM DURING PRE-PURGING
The control box checks the motor speed to ensure it is correct during pre-purging, in two stages.
³STAGE ONE: motor operation checked at maximum rpm.
If the motor is not working at maximum rpm during this stage, the start-up programme is repeated, with
up to 3 attempts made, after which there is a lockout.
³STAGE TWO: motor operation checked at START rpm.
If the motor is not working at START rpm during this stage, the start-up programme is repeated, with up
to 3 attempts made, after which there is a lockout.
If attempts occur both during stage one and stage two, the maximum number of attempts is still 3. When
the start-up programme is repeated for the fourth time, incorrect motor rpm will result in lockout.
4.10 POST-PURGING FUNCTION
Post-purging is a function that keeps air purging on even after the burner switches off. The burner switches
off when the limit thermostat (TL) opens, consequently cutting off the fuel supply to the valves.
To use this function the reset button must be pressed when the limit thermostat is not switched over
(BURNER OFF).
Post-purging time can be set to a maximum of 6 minutes, proceeding as follows:
³Press and hold the reset button for at least 5 seconds until the indicator LED changes to red.
³Set the desired time by pressing the button the appropriate number of times: once = post-purging for
1minute.
³After 5 seconds the control box automatically shows the set minutes through the red LED pulses: 1 led
pulse = post-purging for 1 minute.
To reset this function, press and hold the button for at least 5 seconds at least, till the LED indicator goes red
then release it without performing any operation, then wait for 20 seconds for the burner to restart.
If during post-purging there is a new request for heat, post-purging time is halted and a new burner operating
cycle starts when the limit thermostat (TL) switches over.
The control box's factory settings are as follows: 1 minute = post-purging for 1 minute.
4.11 LOGGING OF BURNER OPERATING PARAMETERS
With this control box, data - i.e. the number of lockouts that have occurred, the type of lockout that has occurred
(just the last one) and the gas valve opening operating time - can be logged even when there is no power
supply. That way, you can determine how much fuel has been consumed during operation. For the display of
these parameters, it is necessary to connect the diagnostic software kit as described in paragraph (1.2) page 2.

3350
15 GB
4.12 FUNCTION SETTING PROCEDURE USING RESET BUTTON
4.13 CONTROL BOX RESET (USING BUILT-IN BUTTON)
To reset the control box, proceed as follows:
³Press and hold the reset button down for between 1 and 2 seconds.
If the burner does not restart, you must make sure the limit thermostat (TL) is closed.
Warning:
If you hold the reset button down for more than 2 seconds, the control box enters visual diagnostic mode
and the signalling LED begins to blink (see paragraph 5.1, page 16).
To reset the control box, you must press the reset button again.
4.14 CONTROL BOX RESET (VIA REMOTE CONNECTION)
Socket XP7 has an input B4 provided for the control box's remote resetting.
5. MAINTENANCE
Before cleaning or performing checks, switch off the burner’s power supply with the system’s master
switch and close the gas shutoff valve.
The burner requires periodic maintenance carried out by a qualified and authorised technician in conformity
with legislation and local standards.
Scheduled maintenance is vital for the smooth operation of the burner; it avoids waste of fuel and reduces pol-
lutant emissions into the atmosphere.
FUNDAMENTAL OPERATIONS TO BE CARRIED OUT ARE AS FOLLOWS:
³Make sure the air intake areas and ducts taking the flue gases away do not feature any obstructions or
restrictions.
³Electrical wiring
Check that the burner and gas train electrical connections are correct.
³Gas leaks
Make sure there are no gas leaks in the following areas:
- on the meter-burner pipework
- on the mixer/valve connection
- on the burner fastening flange where the seal is fitted.
³Combustion head
Inspect the combustion head and make sure the fabric is undamaged and does not features large or
deep holes or corroded areas. Also make sure that no parts have warped as a result of high
temperature.
³Electrode unit
Make sure neither the electrodes nor probe feature marked warping or oxidation on surfaces. Make sure
distances are still in line with those indicated in fig. 4, readjusting to the right values where necessary.
Where necessary, remove oxide from the surface of the probe with abrasive paper.
Control box function
control box
Action with the reset
button
Possible Reset button
use status
Reset 1 to 2 seconds After control box lockout
Visual diagnostics of lockout
causes (5.1) 3 seconds After control box lockout
Post-purging (4.9) 5 seconds then press
once = 1 minute
With limit thermostat (TL) not
switched (burner off)
Resetting set functions 5 seconds With limit thermostat (TL) not
switched (burner off)
Resetting operating parameters 5 seconds With limit thermostat (TL) switched
during pre-purging

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16 GB
³Gas train
Check valve setting and proportionality of operation by analysing flue gases. Check the valve/manifold
compensation pipe.
³Combustion
Leave the burner operating in steady state for approx. ten minutes, ensuring that all components
indicated herein have the proper settings.
Then carry out a combustion check verifying:
OPercentage of CO2(%); OCO content (ppm); ONOx content (ppm);
OIonization current (µA); OFlue gases temperature at stack.
Adjust burner if combustion values encountered at the beginning of operation do not meet the standards in
force or, whatever the case, do not indicate satisfactory combustion
Note the new combustion values down on a suitable sheet: they will come in handy when next checking.
5.1 VISUAL DIAGNOSTICS CONTROL BOX
The control box features a diagnostics function through which any causes of malfunctioning can be identi-
fied (indicator: RED LED). To use this function, you must press and hold the reset button for at least 3 sec-
onds once it has entered the safety condition (lockout).
The control box generates a sequence of led pulses, which is repeated at constant 2-second intervals.
The sequence of led pulses issued by the control box identifies the possible types of malfunction, which are
listed in the table below.
To reset the control box after the diagnostics display, press the lockout reset button.
SIGNAL PROBABLE CAUSE
2Pulses
No stable flame signal is detected at the end of the safety time for the fourth igni-
tion attempt:
– faulty ionisation probe;
– faulty gas valve;
– neutral/phase inverted;
– faulty ignition transformer;
– poor burner adjustment (insufficient gas).
4pulses
Flame detected in chamber before burner firing or at switch-off:
– flame detected before or after the limit thermostat has switched;
– flame detected during pre-purging;
– flame detected during post-purging.
6 pulses
Loss of purging air:
– air loss during pre-purging;
– motor speed (rpm) not correct during pre-purging.
7pulses
Flame goes out 4 times during operation:
– poor burner adjustment (insufficient gas);
– faulty gas valve;
– short circuit between the ionization probe and earth.
2sPulses Pulses
RED LED illuminated
press reset for 3 sec.
Interval
WARNING

3350
17 GB
6. FAULTS / SOLUTIONS
Below is a list of some of the causes and possible solutions to a series of problems that might be encountered
and could cause a failure to start or irregular burner operation. The indicator inside the control box's reset but-
ton (1, fig. 1, page 2) lights when there is trouble, which in most cases is an operating malfunction. When this
indicator lights, burner operation can only be resumed after pushing the reset button all the way in. After this
if the burner functions correctly, the lockout can be attributed to a temporary fault. However, if lockout contin-
ues, you must determine the cause of the problem and take the action illustrated in the solution column in the
tables below.
6.1 START-UP PROBLEMS
FAULTS PROBABLE CAUSE SUGGESTED REMEDY
The burner doesn’t
start when the limit
thermostat closes.
Lack of electrical supply.
Check for voltage at L1-N terminals in
7-pin plug.
Check the conditions of the fuses.
Check that safety thermostat is not
locked out.
Gas is not supplied.
Check gate opening.
Make sure that valve has changed
over to open position and that there
are no short circuits.
The connections in the control box
are wrongly inserted.
Check and connect completely all the
plugs.
Burner performs pre-
purging and ignition
cycle normally and
locks out after 3 igni-
tion attempts.
Phase-neutral connection is invert-
ed. Swap them over.
The wiring to the earth is lacking or in-
effective. Make earth connection efficient.
Valve lets too little gas through. Check supply grid pressure and/or ad-
just valve as indicated herein.
Gas valve is defective. Replace.
Electric ignition arc is irregular.
Make sure connectors are inserted
properly.
Make sure electrode is in the right po-
sition as indicated herein.
Inspect quality of ceramic insulator.
Ionisation probe has a ground fault or
is not in contact with flame, or there is
a break in its wiring to control box, or
there is a ground fault due to its insu-
lation being defective.
Check right position and, if necessary,
adjust as indicated herein.
Restore electrical connection.
Replace faulty lead.
Gas is not supplied.
Check gate opening.
Make sure that valve has changed
over to open position and that there
are no short circuits.

3350
18 GB
6.2 TROUBLE DURING OPERATION
Burner starts with an
ignition delay.
Ignition electrode is wrongly posi-
tioned. Adjust properly as indicated herein.
Air output is too high. Set the air output according to the
instructions of this manual.
Valve not open enough with insuffi-
cient gas allowed through. Set correctly.
The burner does not
pass through the pre-
purging and locks out.
Flame is detected. Valve defective: replace.
FAULTS PROBABLE CAUSE SUGGESTED REMEDY
Burner locks out
during operation.
Valve lets too little gas through. Check supply grid pressure and/or ad-
just valve as indicated herein.
Valve is defective. Replace.
Probe has ground fault.
Check right position and, if necessary,
adjust as indicated herein.
Clean or replace ionisation probe.
Flame disappears four times. Check gas supply grid pressure and/or
adjust valve as indicated herein.
FAULTS PROBABLE CAUSE SUGGESTED REMEDY

3350
19 GB
7. WARNING AND SAFETY
The dimensions and type of the boiler's combustion chamber must have specific values to achieve combus-
tion with the lowest rate of pollutant emissions.
We therefore recommend you consult the Technical Service Department before choosing this type of burner
for work in conjunction with a certain boiler. Qualified personnel are those with the professional and technical
requirements indicated by law no. 46 dated March 5, 1990.
The commercial organisation has a widespread network of agencies and technical offices whose personnel
participates periodically in instructional and refresher courses at the Company Training centre.
This burner must only be used for the application it was designed for.
The manufacturer is relieved of any contractual or non-contractual liability for injury to people or animals or
for damage to property caused by incorrect installation, adjustment, maintenance or improper use.
7.1 BURNER IDENTIFICATION
The product Identification Plate gives the serial number, model and main technical and performance data.
If the identification Plate is tampered with, removed or missing, the product cannot be clearly identified, thus
making any installation or maintenance work potentially dangerous.
7.2 BASIC SAFETY MEASURES
³The unit must not be used by children or inexpert persons.
³Under no circumstances may intake grilles or heat dissipation grilles or the purging openings in rooms
where the control box is installed be plugged with rags, paper or anything else.
³Unauthorised persons must not attempt to repair the unit.
³Pulling or twisting electric cables is dangerous.
³No cleaning must be performed unless the unit is disconnected from the power mains.
³Do not clean the control box or any of its parts with substances that can easily catch fire (e.g. petrol, al-
cohol, etc.). The casing must be cleaned using just soapy water.
³Do not place anything on the burner
³Do not block or reduce the size of vents in the room where the boiler is installed.
³Do not leave flammable substances and containers in the room where the unit is installed.