Troubleshooting
6-4
IC-SA-1511 (02/2014)
V/LNV Series Manual
Problem
Possible Causes
Pilot Flame, but No
Main Flame
1. Insufficient pilot flame.
2. Gas fired unit:
a. Manual gas cock closed.
b. Main gas valve inoperative.
c. Gas pressure regulator inoperative.
3. Oil fired unit:
a. Oil supply cut off by obstruction, closed valve, or loss of suction.
b. Supply pump inoperative.
c. No fuel. Broken, loose, or missing oil pump coupling.
d. Main oil valve inoperative.
e. Check oil nozzle, gun, and lines.
4. Flame detector defective, sight tube obstructed or lens dirty.
5. Insufficient or no voltage at main fuel valve circuit terminal.
Burner Stays in
Low-Fire
1. Pressure or temperature above modulating control setting.
2. Manual-automatic switch in wrong position.
3. Inoperative modulating motor.
4. Defective modulating control.
5. Binding or loose linkages, cams, setscrews, etc.
Shutdown Occurs During
Firing
1. Loss or stoppage of fuel supply.
2. Defective fuel valve, loose electrical connection.
3. Flame detector weak or defective.
4. Scanner lens dirty or sight tube obstructed.
5. If the programmer lockout switch has not tripped, check the limit circuit for an
opened safety control.
6. If the programmer lockout switch has tripped:
a. Check fuel lines and valves.
b. Check flame detector.
c. Check for open circuit in running interlock circuit.
d. The flame failure light is energized by ignition failure, main flame failure,
inadequate flame signal, or open control in the running interlock circuit.
7
. Improper air/fuel ratio (lean fire).
a. Slipping linkage.
b. Damper stuck open.
c. fluctuating fuel supply.
Temporary obstruction in the fuel line.
Temporary drop in gas pressure.
8. Interlock device inoperative or defective.
9. Air in the oil lines. Bleed lines.