15
Boiler inspection and maintenance
Logano G
C
124 II – 6 720 804 440 (2012/11)
27
15.8 Troubleshooting the GC124 II
Equipment required: Wiring diagrams (
chapter 17, page 30) and
voltage detectors for 120 VA
C
and 24 VA
C
.
Fig. 41 Troubleshooting the GC 124 II
Start
Close gas valve. Set thermostat
(control) to require heat (flue
baffle open).
Switch on power.
Observe ignition sparks in gap
between electrode and sensor
through sight glass.
•
Check electrical power source, low-voltage transformer, thermostat (con-
trol) and wiring. Check that the flue baffle (if installed) is open and the limit
switch is present.
No
No
No
Open main gas valve. Ignition
flame is burning.
•
Check that all manually operated baffles are open; check that gas con-
nections and pressures are correct and that ignition gas nozzles are not
blocked.
•
Check electrical connection between automatic ignition and ignition timer
on the gas fitting.
•
If the voltage is correct replace gas fitting, otherwise replace automatic ig-
nition.
No
System operates until the heat
requirement ends.
•
Check ignition wiring and ground for continuity. Note: If the ground is
weak or faulty, the system may switch off at random, even if the heating
system operates correctly when checked.
•
Check that the ignition flame surrounds the electrode and burns evenly
with a bluish flame. If OK replace electrode.
•
If everything is OK replace automatic ignition.
No
Heat requirement ended, system
switches off, flue baffle closes.
End of troubleshooting
Repeat procedure until heating system operates properly.
•
On models with flue baffle check that it operates and limit switches are
present. If necessary, replace flue baffle.
•
Check ignition wiring, ceramic insulator of ignition electrode and ignition
gap, adjust if necessary.
•
Check the ignition cable contact for signs of scorching or kinking.
•
Replace automatic ignition unit.
No
Ignition spark stops as soon as
ignition flame burns.
•
Check ignition wiring and ground for continuity.
•
Check ignition electrode.
•
Check electrical connections between ignition electrode and automatic ig-
nition.
•
Check whether the ceramic insulator in the ignition electrode is broken.
•
Check that the ignition flame surrounds the electrode and burns steadily
with a bluish flame.
•
Adjust ignition flame.
•
If this does not correct the fault, replace the automatic ignition unit.
No
Main burner ignites.
•
Use MV-MV/PV terminals to check 24 V alternating current, closed cur-
rent circuit at the automatic ignition. If there is no voltage, replace auto-
matic ignition.
•
Check electrical connection between automatic ignition and gas fitting. If
OK, replace gas fitting.
•
Check operation of thermostat (control).
•
Disconnect 24V connection to gas fitting. If gas fitting closes, check ther-
mostat and connection line again.
•
If the gas fitting does not close, replace gas fitting.
•
Check if the fuse in 24 V circuit is still working.
6 720 804 440-52.1T
Содержание Logano GC 124 II
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