Vermont Casting NVC36 - Manual (Page 15)

15
NVC Series B-Vent
20000194
Troubleshooting
FP649
Turn gas supply off
Turn ON/OFF Switch
to call for heat. NO
NO
NO
NO
NO
NO
NO
Spark across
Ignitor Sensor gap
Power to module
(24V nominal)
YES
YES
YES
YES
YES
YES
YES
Turn gas on
Pilot burner lights?
Spark stops when pilot
is lit?
Main Burner lights?
Replace Module
START
Line Voltage (120VAC)
Low Voltage Transformer
(19.5 minimum VAC)
ON/OFF Switch
Wiring connections
Thermodisk
Check continuity of ignition cable and ground wire.
Clean flame rod.
Check electrical connections beween flame rod and module.
Check for cracked ceramic flame rod insulator.
Check that pilot flame covers flame rod and is steady blue.
Adjust pilot flame.
If problem persists, replace module.
Unplug Ignition Lead
and check spark
at module
(24VAC nominal)
Spark OK?
Check ignition cable, ground wiring, Ceramic Insulator and gap. Correct as necessary
Check boot of ignition cable for signs of melting or buckling. Take protective
actions to shield cable and boot from excessive temperatures.
Check for 24VAC across MV-MV/PV terminals. If no voltage, replace module.
Check electrical connections between module and gas control. If okay, replace gas
control or gas control operator.
Check for continuity of igniton cable and ground wire. NOTE: If ground is poor or
erratic, shutdowns may occur occasionally even though operation is normal
at time of checkout.
Check that the pilot flame covers flame rod and is steady and blue.
If checks are okay, replace module.
Troubleshooting
Ends
Check that all manual gas valves are open, supply tubing and pressures are good,
and pilot burner orifice is not blocked.
Check electrical connections between module and pilot operator on gas control.
Check for 24VAC across PV-MV/PV terminals on module. If voltage is okay, replace
gas control. If not, replace module.
NOTE: If S8600B goes into lockout, reset system.
NOTE: If S8600B goes into lockout, reset system.
CHECK :
System runs until
ON/OFF switch is in
"OFF" position
Honeywell Electronic Ignition