Riello G400 Quick start guide

Installation, use and maintenance instructions
2903334 (10) - 06/2018
Forced draught natural gas/propane burner
Single stage operation
CODE MODEL
3757225 G400
GB

Original instructions

1 2903334
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TABLE OF CONTENTS
Installation instructions and owner's handbook. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Step by step procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Serial number identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Burner components identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Burner dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Electrode & flame probe adjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Typical gas train layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Installing the burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Installation of sediment trap & burner supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Factory wiring diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Field wiring diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Setting up the burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Step by step procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Operating faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Air gate adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Diaphragm installation and combustion head setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Manifold pressures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Pressure working chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Combustion chamber size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Combustion checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Burner start-up cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Problem solving guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Owner information & routine maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Installation data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Propane burner application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Exploded spare parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Spare parts list. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Burner start up report. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

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INSTALLATION INSTRUCTIONS AND OWNER'S HANDBOOK
CAUTION:
All gas burners MUST be installed by trained and licensed technicians.
WARNING:
Installation of this burner must conform with local codes or, in the absence of local codes, with the
Standard for the Installation of Domestic Gas Conversion Burners, ANSI Z21.8-1984, and Addendum,
Z21.8a-1989, and the National Fuel Gas code, ANSI Z223.1-1984, and CAN/CGA B149.1 &.2. If an external
electrical source is utilized, the conversion burner, when installed, must be electrically grounded in ac-
cordance with local codes or, in the absence of local codes, with the national Electrical Code, ANSI/
NFPA No. 70-1990 and CSA Electrical Code.
Owner is required to retain this manual for future reference.
WARNING:
If the information in these instructions is not followed exactly, a fire or explosion may result causing
property damage, personal injury or death.
Do not store or use gasoline or any other flammable vapours or liquid in the vicinity of this or any other
appliance.
WHAT TO DO IF YOU SMELL GAS:
1) Do not try to light any appliance.
2) Do not touch electrical switches; do not use any phone in your building.
3) Immediately call your gas supplier from a neighbour's phone.
Follow the gas supplier's instructions.
4) If you cannot reach your gas supplier, call the fire department.
Installation and service must be performed by a qualified installer, service agency or the gas supplier.
TECHNICAL SPECIFICATIONS
FIRING RATE 170,000 TO 400,000 Btu/hr
NATURAL GAS PROPANE
GAS SUPPLY PRESSURES MIN. 5" wc
MAX. 7" wc
MIN. 12" wc
MAX. 14" wc
MANIFOLD PRESSURES MIN. 3" wc
MAX. 5" wc
MIN. 3" wc
MAX. 5" wc
POWER
MOTOR
CONTROL MODULE
120 Volts 60 Hz 1 phase
232T 2.2 Amps 3250 rpm
525 SE/A ELECTRONIC

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GENERAL INFORMATION
Your Riello gas burner comes to you completely assembled and factory wired, ready for installation.
Models equipped with the short combustion head have a fixed flange, which bolts directly to the front of the appliance.
When equipped with the long combustion head, the burner comes with a universal flange, which when bolted to the
appliance, allows the burner to be adjusted for exact positioning in the combustion zone.
STEP-BY-STEP PROCEDURE
1) Remove the burner from the carton, taking care not to lose any of the supplied accessories.
Check for signs of physical damage.
2) Bolt the combustion head and burner to the appliance. Be sure to install the supplied mounting gasket.
Ensure that the burner is level (we suggest using a spirit level) and that the combustion head is centred in the ap-
pliance port. Refer to page 7 for positioning of combustion head relative to the chamber.
3) Check that all gas train connections are tight and make your connections to the incoming gas supply.
a) A sediment trap must be provided. See page 8.
b) If not already installed, a manual shutoff valve must be supplied. This valve must be upstream of the burner gas
train supply connection.
c) A 1/8" NPT plugged tapping must be installed immediately upstream of the burner gas train supply connection
and must be accessible for a test gauge.
d) If required by local codes, provide gas vent lines at the gas regulators and valve (Riello gas trains are equipped
with vent limiting diaphragms).
e) Perform required gas pressure test on incoming gas supply lines.
NOTE: Details of sediment trap, manual gas valve, and pressure test point, and line pressure test point can be found
on page 8.
4) To make electrical connections, refer to field wiring diagram on page 9. A manual disconnect switch must be in-
stalled in the incoming lines. Wiring to the low voltage-switching relay, if used, (Honeywell R8038A) must be rigid
conduit or flexible approved cable.
CAUTION:
Label all wires prior to disconnection when servicing controls.
Wiring errors can cause improper and dangerous operation.
Verify proper operation after servicing. (Step 5 e below.)
CAUTION:
The phase (HOT) wire must be connected to the black lead of the 24v relay if used; neutral to the white
lead. Do not reverse the polarity.
The burner will not operate with the Phase/Neutral reversed, and the control box may be damaged.
5) Check the burner functions as follows:
a) Make a final check on both the gas and electrical connections.
b) Loosen the screw in the manifold gas test point and install an appropriate manometer.
c) Set the thermostat at its highest setting.
d) Switch on power.
e) With the manual gas valve turned off, press the burner reset button (9, page 4), and allow the burner to run
through a complete cycle to ensure that the sequence of operations is correct. A full starting cycle should take
approximately 40 seconds from a no power condition until burner lockout; refer to the start-up cycle chart found
on page 14.
f) Once burner is operational (up and running) a final gas leak check must be completed on the gas train.
6) If the burner is installed on a central warm air furnace, affix the mandatory warning labels to the furnace fan cover
door (inside and outside).

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SERIAL NUMBER IDENTIFICATION
Your Riello burner may have been manufactured in more than one location and therefore there are two possible serial
number identification.
The Riello 9 character serial number, example,
06 01 12345, is identified as follows:
06 = Last two digits of the year of manufacture;
01 = Week of manufacture;
12345 = Increment of 1 for each burner produced – specific to
product code – reset to zero each January 1st.
The Riello 15 character serial number, example,
8511344 18 01 0003, is identified as follows:
BURNER COMPONENTS IDENTIFICATION
8511344 Burner product code;
18 Last two digits of the year of manufac-
ture;
01 BI-week of manufacture;
0003 Increment of 1 for each burner pro-
duced – specific to product code –
reset to zero each January 1st.
(06) (01) (12345)
Year of
manufacture
BI-week of
manufacture Increment
Year of
manufacture Increment
Burner
product code
BI-week of
manufacture
(8511344) (18) (01) (0003)
LN
L
N
1 – Control box
2 – Air pressure switch
3 – Screw for fixing the cover
4 – Cable grommet
5 – Wiring terminal block
6 – Screws for fixing the air-damper
7 –Air damper
8 – Capacitor
9 – Reset button with lock-out lamp
10 – Gas valve transformer 120V / 24V
7
6
8
2
3
1 9
4 5
D7554
10

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BURNER DIMENSIONS
ELECTRODE AND FLAME PROBE ADJUSTMENTS
WARNING:
Do not turn the ignition electrode. Leave it as shown in the drawing.
If the ignition electrode is put near the ionization probe, the amplifier of the control box may be damaged.
NOTE: Actual available insertion length must be measured from tip of end cone to face of mounting gasket.
Model G400 A B C D E F G G1 H I J
inches 10 5/16 12 1/64 2 13/32 1 19/64 3/413 5/84 21/64 10 33/64 4 1/85 19/32 8 1/32
mm 262 305 61 33 19 346 110 267 105 142 204
A
B
D
GF
G1
H
J
I
C
D7332
E
5 1/2”-140mm
7 1/2” - 190 mm
8 15/32” - 215 mm
7 3/32” - 180 mm
3 31/32” 101 mm
60°
45°
30°
D7351
44
0
-1
15
Ionization probe
1.5
Diffuser
Ignition electrode
Propane orifice
Probe Electrode
A
B
A B
mm 8 ± 0.5 4 ± 0.5
inch 5/16”5/32”
2.2
D7403

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TYPICAL GAS TRAIN LAYOUT
THE GAS TRAIN LEAVES THE FACTORY SET AT 3.5” wc.
ATTENTION
This gas train scope of supply meets the minimum controls requirements according to CSA Canada and USA
regulations. Any additional requirements needed to meet local codes are the responsibility of others.
VALVE LEGEND
1- Gas supply & flow direction of gas
2- Gas supply main shtoff manual valve (field supplied)
3- Gas supply pressure test point (field supplied)
4-Valve
5- Gas burner manifold test point
GAS SUPPLY PRESSURE RANGES:
NATURAL GAS PRESSURE:
min. 5” wc - max. 7” wc
LP PROPANE GAS PRESSURE
min. 12” wc - max. 14” wc
TOP VIEW OF GAS CONTROL
FIELD SUPPLIED RIELLO SUPPLIED
1 2 3 4 5
D7343

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INSTALLING THE BURNER
A) Burner Chassis
B) Combustion Head Assembly
1) Locking Nut
2) Mounting Plate surface
3) Insulation Gasket
Separate the combustion head of the burner from the chassis (A)
by removing the locknut (1). Install the combustion head into the
boiler.
Typical insertion depth, the front edge of the combustion head is
flush with the inside surface of the appliance mounting surface
(2).
Use this checklist prior to installation:
1) Check the input/output requirements of the appliance. We
suggest that the appliance output should be approximate-
ly 85% of input (85% efficiency).
2) Check the dimensions of the combustion chamber for correct sizing against the input requirements of the application.
3) Check that there is sufficient air for proper combustion and adequate ventilation.
Local codes should be followed. In the absence of local codes, refer to the NFPA Manual No. 31, CAN/CGA
B149.1 &. 2, ANSI Z223.1-1984 and Addendum 221.8A 1989.
4) Check that you have adequate space for servicing the equipment.
The Riello burner requires a minimum of 13 inches clear space behind the red cover.
This is required to allow easy removal of the cover for servicing and periodic maintenance.
5) Check that the chimney is of sufficient area to handle the exhaust gases.
Make sure the chimney is clear and there are no obstructions.
6) Barometric draft regulators must be of the double acting type, and must be installed in accordance with the draft
regulator manufacturer's instructions.
Single acting barometric dampers are not permitted.
For further clarification, refer to ANSI Z21.8-1984 and Z21.17A-1993.
IMPORTANT:
A vent shutoff system shall be applied to a barometric damper installed in the venting system at the time
of conversion of the appliance.
This will electrically disconnect the burner should there be a blockage in the vent (chimney).
The installer must identify the main electrical power switch and manual gas shut off valve, for emergency
conditions. The burner cover must be in place and secured before the burner is placed in operation.
13 2
AB

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INSTALLATION OF SEDIMENT TRAP AND BURNER SUPPLY
Gas piping to the burner must be 1/2-inch minimum. Install only a full-ported shutoff valve. The valve must be located
outside the appliance jacket, and the pressure gauge port must be accessible.
PRESSURE TEST-OVER 1/2 PSIG.
The appliance and its individual shutoff valve must be disconnected from the gas supply piping system during any
pressure testing of the system at a test pressure in excess of 1/2 PSIG.
PRESSURE TEST-1/2 PSIG OR LESS
The appliance must be isolated from the gas supply piping system by closing its individual manual shutoff valve dur-
ing any testing of the gas supply piping system at test pressures equal to or less than 1/2 PSIG.

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FACTORY WIRING DIAGRAM
NOTE:
The SAFETY SWITCH on the 525SE CONTROL BOX is
equipped with a contact allowing remote sensing of burner
lockout.
The electrical connection is located on the CONTROL BOX ter-
minal 4 as indicated. Should burner lockout occur, the 525SE
CONTROL BOX will supply a power source of 120 Vac to the
connection terminal.
The maximum allowable current draw on this terminal is 1A.
Blue
White
Black
D4703
LEGEND
C- Capacitor
CN... - Connectors
E- Ignition electrode
MB - Terminal board
MV - Motor
PA - Air pressure switch
SO - Ionization probe
TB - Burner earth
TV - Transformer 24V
Brown
Control box
Remote
lock-out
signal
Fuse Fuse
Service
D4704
switch
Service
switch
120V controlled 24V controlled
Operating
control
TB
TB
Operating
control
FIELD WIRING DIAGRAM
IMPORTANT:
Terminal 4 is to be used only for the connection of a
remote sensing device.
If a neutral or ground lead is attached to terminal 4,
the control box will be damaged should lockout occur.

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SETTING UP THE BURNER
After burner output has been determined, use TABLE 1 below AS AN INITIAL GUIDE for burner settings.
All settings in this table were obtained under the following conditions.
0 (zero) draft in the combustion zone; Standard lab test boiler;
Inlet gas pressure range as in table 1; Steady state (HOT) operating conditions.
Burner input decreases with increasing the combustion chamber pressure.
Once installed, a higher or lower burner input can be achieved by raising or lowering the manifold pressure from - 0.5” wc.
to +1.5” wc. Pressure changes can only be made when the burner is running. The typical working manifold pressure is 3.5”
wc. (both for natuaral gas and propane).
SAFETY TEST - WITH GAS BALL VALVE CLOSED
It is fundamental to ensure the correct execution of the electrical connections between the gas solenoid valves and the burner to perform
safely the commissioning.
For this purpose, after checking that the connections have been carried out in accordance with the burner's electrical diagrams, an ignition
cycle with closed gas ball valve -dry test- must be performed.
1 The manual ball gas valve must be closed
2 The electrical contacts of the burner limit switch need to be closed
3 Ensures closed the contact of the low gas pressure switch
4 Make a trial for burner ignition.
The start-up cycle must be as follows:
– Starting the fan for pre-ventilation
– Performing the gas valve seal control, if provided
– Completion of pre-ventilation
– Arrival of the ignition point
– Power supply of the ignition transformer
– Electrical Supply of solenoid gas valves
Since the manual gas ball valve is closed, the burner will not light up and its control box will go to a safety lockout condition.
The actual electrical supply of the solenoid gas valves can be verified by inserting a tester. Some valves are equipped with light signals
(or close/open position indicator) that turn on at the same time as their power supply.
STEP BY STEP PROCEDURE
1) Set air gate. See AIR GATE ADJUSTMENT on page 11.
2) Set gas diaphragm and combustion head.
See DIAPHRAGM INSTALLATION AND COMBUSTION HEAD SETTING on page 12.
3) Set the manifold pressure using the following method.
a) In order to determine existing manifold pressure, start the burner.
At the end of the prepurge cycle (approx. 30s), the gas valve is energized.
During the 5 sec. trial for ignition, note the observed manifold pressure. If the burner lights and continues to
run, go to step (d).
b) Compare the observed manifold pressure from step (a) to the required value from TABLE 1.
Gas inlet
pressure range Diaphragm Manifold gas pressure
Burner
output
Head
setting
Air gate
setting
“wc Marking “wc Btu/hr Nocth Notch
NATURAL GAS
5.0 - 7.0
C1
3.5
170,000 0 1.1
C2 201,199 1 1.6
C3 243,674 2 1.95
C4 301,426 3 2.3
C5 366,629 4 2.5
C6 400,000 4 3.0
WARNING
IF THE ELECTRICAL SUPPLY OF THE GAS VALVES OCCURS AT UNEXPECTED TIMES, DO NOT OPEN MANUAL
GAS BALL VALVE, SWITCH OFF POWER LINE; CHECK THE WIRES; CORRECT THE ERRORS AND REPEAT THE
COMPLETE TEST.

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c) Repeat step (a), making adjustments to the gas valve, until flame is established.
d) Once flame has been established, set your manifold pressure to the desired value from TABLE 1.
4) Check combustion gases using proper combustion analysis equipment to ensure safe levels of CO2 and CO dur-
ing appliance heat up.
The gas valve should be used to make any necessary adjustments to ensure safe combustion.
At this point do not adjust the air or head settings unless absolutely necessary.
5) Allow burner to run until normal operating temperatures and conditions have been achieved.
6) a) Clock the gas meter to determine actual burner output.
b) Set the manifold pressure, by adjusting the gas valve, to achieve desired output.
c) Check combustion gases once again to ensure safe operation.
Make sure the burner cover is in place and air gate locking screws are secure for all combustion analysis.
Adjust air gate if necessary (refer to page 11). A qualified technician must do this test.
The maximum recommended CO2 level for natural gas is 10%; the maximum recommended level for propane
gas is 12%. The recommended flue gas temperature is from 350°F to 550°F.
7) After completing the adjustments, remove the manometer and tighten the screw inside the manifold test point. Re-
place the regulator cap on the gas valve.
8) Complete the adjustment data tag, described on page 15.
Explain the burners essential functions (starting and stopping) to the owner.
Do not forget to give the dealer or service company's name and address.
Please see page 15 for information on burner maintenance procedures.
NOTE: Do not assume the heating system is operating at optimum performance.
THERE IS NO SUBSTITUTE FOR PROPER COMBUSTION TESTING!
OPERATING FAULTS
The integrated control system is self-checking.
The cycle from start up to flame establishment, takes approximately 70 seconds.
The burner will go into lockout under the following circumstances:
a) Burner fails to ignite;
b) The ionization probe is grounded;
c) Opening of the air pressure switch or the normally open contacts of the air pressure switch not making.
Should overheating of the appliance occur, shut off the manual gas valve to the burner.
Do NOT shut off the switch to the circulating pump or blower fan.
SHUT DOWN PROCEDURE
Switch off electrical power to the unit. Close the manual supply gas valve.
START UP PROCEDURE
See page 7.
NOTE:
If an external electrical source is utilized, the conversion burner, when installed, must be electrically grounded in
accordance with local codes.
In the absence of local codes, refer to the National Electrical Code, ANSI/NFPA 70-1990.
In Canada follow the Canadian Electrical Code Part 1 CSA C22.1.

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AIR GATE ADJUSTMENT
To regulate the combustion air, adjust the manual air gate (3), by loos-
ening the locking screws (4).
Once the optimal adjustment is reached, tighten the locking screws
(4).
EXAMPLE SETTING - (for natural gas)
To set the air intake for a desired burner output of 243,600 Btu/hr, use
TABLE 1 to determine the correct air gate setting.
In this case, the setting would be 1.95 for natural gas.
Turn the manual air gate (3) until the arrow points to 1.95 on the scale.
Tighten locking screws (4).
All settings in TABLE 1 are obtained with zero (0) pressure in the
combustion zone and at normal operating temperatures. i.e., steady
state hot conditions.
Note:
Burner must be fired ONLY with fuel that is listed on the burner serial label.
3
D5231
44

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DIAPHRAGM INSTALLATION AND COMBUSTION HEAD SETTING
A proper diaphragm (C) has to be installed in the combustion head gas line, according to TABLE 1. A complete set of gas
diaphragms is delivered with the burner packaging as equipment. The burner leaves the factory with the C6 diaphragm
already installed. In case another diaphragm has to be installed, following the instructions below.
To remove the drawer assembly from the manifold (B), follow the procedure below:
1) Disconnect 24v leads at the gas valve.
2) Separate the burner chassis from the combustion head by removing the locknut.
3) Loosen the two Allen screws (A) without taking them out.
4) Withdraw the head, turning it 180 degrees.
5) Pull out head, leaning it towards the bottom.
6) Remove the ignition electrode (D) and the ionization probe (E).
7) Unscrew the screw (F) and remove the gas diffuser (G).
8) Install the proper diaphragm (C) and seal according to TABLE 1.
9) Refit following the above procedure in the reverse order (verify the ignition electrode and the ionization probe posi-
tions according to page 5).
Slide the elbow (B) so that the number on the indicator scale aligns with the back edge of the air tube.
See TABLE 1 for set points. Tighten the two Allen screws (A).
Example (for natural gas):
For a desired burner output of 243,600 Btu/hr, the diaphragm would be C3 and the combustion head setting would
be 2.
All settings in TABLE 1 are obtained with zero (0) pressure in the combustion zone and at normal operating tempera-
tures. i.e.; steady state hot conditions.
Note: Burner must be fired ONLY with fuel that is listed on the burner serial label.
MANIFOLD PRESSURES
Manifold gas pressure for various firing rates should be set by adjusting the gas regulator of the gas valve, (see figure
at page 6). To check manifold gas pressure, attach a manometer to the manifold test point, shown on typical gas train
layout. Approximate manifold pressure settings are indicated in TABLE 1.
Example (for natural gas):
For a burner to be fired at 243,600 Btu/hr, the manifold pressure would be approximately 3.5" wc.
In case of lower or higher manifold pressure, install an diaphragm with a respectively smaller or bigger hole.
All settings in TABLE 1 are obtained with zero (0) pressure in the combustion zone and at normal operating tempera-
tures. i.e.; steady state hot conditions.
Note: Burner must be fired ONLY with fuel that is listed on the burner serial label.
HIGH ALTITUDE SETTINGS
It should be noted that for higher altitudes more air for combustion is required.
All settings in this manual have been obtained at approximately sea level. Special attention should be paid to air for
combustion for elevations above sea level. If an increase in combustion air is insufficient, the burner must then be de-
rated by approximately 4% for every 1000 feet above sea level.
B
D7349
C
A
D E
F
G

2903334 14
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PRESSURE WORKING CHART
The chart below shows effects of pressure in the combustion zone on the minimum/maximum burner outputs. In this
example, with a maximum operating pressure of 0.6 inches water column in the combustion zone, you will be able to
obtain a maximum of 370,000 Btu/h burner output.
Any change from zero (0) pressure in the combustion zone will affect the Btu output of the burner. To supply the
required input to the appliance, manifold pressure will have to be adjusted to compensate for this condition.
COMBUSTION CHAMBER SIZE
NOTES:
1) Sizes shown above are for cylindrical or wet base boilers, or air cooled heat exchangers.
2) To size the chamber in applications other than wet base boilers, refer to the authority having jurisdiction.
Refer to CAN/CGA B149.1 &. 2, ANSI Z21.8-1984, and ANSI Z223-1-1984.
3) Fire brick or cerafelt chamber materials should have a continuous run temperature rating of 2400 degrees Fahren-
heit and a melting point of 3000 degrees Fahrenheit.
PRESSURE WORKING CHART
Natural and Propane Gas
Pressure
In/wc
Btu/h
kW/h
2.0
1.0
0.0
49.8 108.461.5 73.8 85.0 96.7
410,000
3.0
4.0
370,000330,000290,000250,000210,000170,000
120.1
COMBUSTION CHAMBER SIZE
Recommended Minimum Sizes
Length
26
22
18
14
10
30
Inches
Btu/h400,000350,000300,000250,000200,000150,000
DIAMETER
LENGHT

15 2903334
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COMBUSTION CHECKS
CO2
It is advisable not to exceed a measured reading of 10% CO2 for Natural Gas or 12% CO2 for Propane Gas.
CO
For safety reasons, the value of .02% (200ppm) free air sample must not be exceeded.
IONIZATION CURRENT
The minimum amount of current necessary for the
control box to operate properly is 3 micro Amps DC.
To measure the ionization current, disconnect the
red wire connector and insert a DC micrometer in
series with control box terminal 2 and the ionization
probe, which senses the flame. Refer to the dia-
gram below.
BURNER START-UP CYCLE
PROBLEM SOLVING GUIDE
Burner starting difficulties and their causes:
1) The burner goes through the prepurge period normally. The flame ignites, but the burner goes to lockout within five
seconds.
a) The phase/neutral lines are reversed.
b) The wiring to ground is absent or ineffective.
c) The ionization probe is grounded, or not in contact with the flame, or the circuit to the control box is broken.
d) The spark interferes with the flame signal due to incorrect setting of the electrode.
2) The burner goes to lockout after the prepurge period because the flame does not ignite.
a) Air has not been fully bled from the gas lines.
b) The gas valve is passing too little gas.
c) The spark is irregular or not present.
3) The burner does not start when the thermostat calls for heat.
a) The gas pressure switch (if supplied) does not close contact due to low gas pressure.
b) The 24 volt switching relay is defective.
c) The line switch is off.
d) There is a blown fuse in the panel.
e) Terminals on the control module are bent or loose
f) The motor is defective.
g) The capacitor is defective.
h) The end switch on the air damper is defective.
i) The control box is defective.
j) The air pressure switch is not in the normally closed position.
Ionization probe
Red wire connect
Control box
terminal block
D5006
2
Normal Lock-out, due to light-failure
Thermostat
Motor
Ignition transformer
Valve
Flame
Lock-out
30s min. 5s max. 30s min. 5s max.
D5048
Thermostat
Motor
Ignition transformer
Valve
Flame
Lock-out

2903334 16
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4) The burner continues to repeat the starting cycle without going into lockout.
This is a very specific situation caused when gas pressure in the gas main lines is very close to the value at which
the gas pressure switch has been set. This can be corrected by resetting the gas pressure switch to a lower level.
The gas pressure switch, if required, may be supplied, or may have to be field installed.
5) The burner does not go through prepurge, and the control module goes to lockout. The air pressure switch does
not change over from normally closed to normally open contacts.
This condition exists because there is insufficient air pressure in the combustion head.
OWNER INFORMATION AND ROUTINE MAINTENANCE
SAFETY LOCKOUT
This burner is equipped with multiple interlocking safety devices. In the event of a failure in the flame, or any blockage
of the combustion air supply, the burner will "lock out" in a safety condition. In such an event, an illuminated red
button will show on the centre front of the red cover. To restart the burner, press the button once only. Should the
burner return to the lock out condition, call a qualified service technician or your gas company for assistance.
NOTE: Keep the area around the burner free and clear of all combustible materials, gasoline and other flammable
vapours and liquids. Do not allow any obstructions, which may prevent the free, flow of air to the burner.
MAINTENANCE
Like all precision equipment, your burner will require periodic maintenance. At an interval of 2 months, you should:
1) Visually check the flame if your heating appliance has an observation port.
2) Check and clean the air intake louver to remove any builds up of fluff, dust, pet hair etc.
3) The motor is permanently lubricated and does not need oiling.
For any maintenance or repairs over and above those listed, contact your service technician or gas company. THERE
ARE NO OWNER SERVICEABLE PARTS INSIDE THE BURNER COVER.
Once a year, you should have the burner serviced as indicated below. This service should be performed by your local
authorized Riello dealer.
1) Check burner distributor head and mixing plates. Clean if necessary.
2) Check ignition electrode. Clean, adjust, or replace as necessary.
3) Check the flame sensor rod (ionization rod) for dirt or carbon build up. Clean, adjust, or replace as necessary.
4) Check manifold gas pressure.
5) Check all burner adjustments.
6) Generally clean all exposed parts and components.
7) Do a complete combustion test with the burner cover in place and the air gate locking screws secure.
Your Riello 40 gas burner is only part of your heating system.
Once every year you should have your heating appliance serviced by a qual-
ified service technician.
You should also have the chimney checked, and cleaned if necessary.
INSTALLATION DATA
Note:
This label is supplied in the package with the burner and should be filled
out and affixed to the appliance when the conversion burner is installed.

17 2903334
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PROPANE BURNER APPLICATION
The burner leaves the factory to run on
natural gas. It is available a kit, on request,
that allows the burner to run on propane.
TECHNICAL FEATURES
The thermal output and operating range of
burners converted to use propane are the
same as for burners running on natural gas.
GAS Family 3:
Net calorific value: 24 - 34 kWh/m3
21,000 ÷ 29,300 kcal/m3
Min. pressure 25 - max. 50 mbar.
LIST OF KIT’S COMPONENTS
CONVERSION
On the combustion head of the burners, diaphragm (2) should
be replaced, and natural gas nozzle (1) replaced with the one
used for propane.
Proceed as follows: (fig. A)
Replace diaphragm (2) and replace natural gas nozzle (1) (marked 2.2) with the one supplied used for propane (marked
1.5).
Affix the adhesive label as illustrated in fig. B.
Quantity Component
1
1
1
5
Diffuser 1,5
Adhesive label
Instruction
Diaphragm
1
2
D7346
Fig. A
Fig. B
Adhesive data plate
supplied as equipment
D4005

2903334 18
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SETTING UP THE BURNER
After burner output has been determined, use TABLE below AS AN INITIAL GUIDE for burner settings.
All settings in this table were obtained under the following conditions.
0 (zero) draft in the combustion zone; Standard lab test boiler;
Inlet gas pressure range as in table; Steady state (HOT) operating conditions.
SAFETY TEST - WITH GAS BALL VALVE CLOSED
It is fundamental to ensure the correct execution of the electrical connections between the gas solenoid valves and the burner to perform
safely the commissioning.
For this purpose, after checking that the connections have been carried out in accordance with the burner's electrical diagrams, an ignition
cycle with closed gas ball valve -dry test- must be performed.
1 The manual ball gas valve must be closed
2 The electrical contacts of the burner limit switch need to be closed
3 Ensures closed the contact of the low gas pressure switch
4 Make a trial for burner ignition.
The start-up cycle must be as follows:
– Starting the fan for pre-ventilation
– Performing the gas valve seal control, if provided
– Completion of pre-ventilation
– Arrival of the ignition point
– Power supply of the ignition transformer
– Electrical Supply of solenoid gas valves
Since the manual gas ball valve is closed, the burner will not light up and its control box will go to a safety lockout condition.
The actual electrical supply of the solenoid gas valves can be verified by inserting a tester. Some valves are equipped with light signals
(or close/open position indicator) that turn on at the same time as their power supply.
Gas inlet
pressure range Diaphragm Manifold gas pressure
Burner
output
Head
setting
Air gate
setting
“wc Marking “wc Btu/hr Nocth Notch
PROPANE
12.0 - 14.0
C11
3.5
170,000 0 0.9
C12 198,368 1 1.1
C13 238,170 2 1.5
C14 305,821 3 2.0
C15 334,338 4 2.1
C16 400,000 4 2.73
WARNING
IF THE ELECTRICAL SUPPLY OF THE GAS VALVES OCCURS AT UNEXPECTED TIMES, DO NOT OPEN MANUAL
GAS BALL VALVE, SWITCH OFF POWER LINE; CHECK THE WIRES; CORRECT THE ERRORS AND REPEAT THE
COMPLETE TEST.