Combustion Checks; Burner Start-Up Cycle; Problem Solving Guide - Riello G120 Installation, Use And Maintenance Instructions

COMBUSTION CHECKS

CO
2
It is advisable not to exceed a measured reading of 10% CO
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

Normal
Thermostat
Motor
Ignition transformer
Valve
Flame
Lock-out

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.
2903332
30s min. 5s max.
for Natural Gas or 12% CO
2
Control box
2
terminal block
Thermostat
Motor
Ignition transformer
Valve
Flame
Lock-out
14 GB
for Propane Gas.
2
Red wire connect
Ionization probe
D5006
Lock-out, due to light-failure
30s min. 5s max.
D5048