Troubleshooting
7-2
750-368
CBEX Elite 100-1200 HP
7.1 — Problem-Cause Suggestions
Problem Possible Cause(s)
BURNER DOES NOT
START
1. No voltage at program relay power input terminals.
A. Main disconnect switch open.
B. Blown control circuit fuse.
C. Loose or broken electrical connection.
2. Program relay (flame safeguard) safety switch requires resetting.
3. Limit circuit not completed - no voltage at end of limit circuit program
relay terminal.
A. Pressure or temperature is above setting of operation control.
(Load demand light will not glow.)
B. Water below required level.
1) Low-water light (and alarm horn) should indicate this condition.
2) Check manual reset button (if provided) on low-water control.
C. Fuel pressure must be within settings of low pressure and high
pressure switches.
D. Oil fired unit - burner gun must be in full forward position to close
oil drawer switch.
4. Fuel valve interlock circuit not completed.
A. Fuel valve auxiliary switch not closed.
NO IGNITION 1. Lack of spark.
A. Electrode grounded or porcelain cracked.
B. Improper electrode setting.
C. Loose terminal on ignition cable - or cable shorted.
D. Inoperative ignition transformer.
E. Insufficient or no voltage at pilot ignition circuit terminal.
2. Spark but no flame.
A. lack of fuel - no gas pressure, closed valve, empty tank, broken
line, etc.
B. Inoperative pilot solenoid.
C. Insufficient or no voltage at pilot ignition circuit terminal.
D. Too much air.
3. Low-fire switch open in low-fire proving circuit.
A. Damper motor not closed, slipped cam, defective switch.
B. Damper jammed.
4. Running interlock circuit not completed.
A. Combustion or atomizing air proving switches defective or not
properly set.
B. Motor starter interlock contact not closed.
5. Flame detector defective, sight tube obstructed, or lens dirty.