Boiler inspection and maintenance
13
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We reserve the right to make any changes due to technical modifications.
Installation and maintenance instructions Logano G124X II/SP special gas-fired boiler • Issue 04/2005
13.7 Troubleshooting on the G124X II
Equipment required: Wiring diagrams (
Chapter 16, page 74) and voltage detectors for 120 VAC and 24 VAC.
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 supply, low-voltage transformer, thermostat
(control) and wiring. Check that the Vent Damper (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 vent dampers are open; check that gas
connections and pressures are correct and that main orifices are not
blocked.
•
Check electrical connection between ignition module and connection on
the gas valve.
•
Use MV-MV/PV terminals to check 24 V alternating current at the
automatic ignition. If the voltage is correct replace gas valve, otherwise
replace automatic ignition.
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 pilot assembly.
•
If everything is OK replace ignition module.
No
Heat requirement ended, system
switches off, vent damper
closes.
End of troubleshooting
Repeat procedure until heating system operates correctly.
•
On models with vent damper check that it operates and Limit switches are
present. If necessary, replace vent damper.
•
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 ignition control 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 ignition
module.
•
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 pilot flame.
•
If this does not correct the fault, replace the ignition module.
No
Main burner ignites.
•
Use MV-MV/PV terminals to check 24 V alternating current, closed
current circuit at the automatic ignition. If there is no voltage, replace
ignition control.
•
Check electrical connection between ignition module and gas valve. If
OK, replace gas valve.
•
Check operation of thermostat (control).
•
Disconnect 24-V connection to gas valve. If gas valve closes, check
thermostat and connection line again.
•
If the gas valve does not close, replace gas valve.
