Breakdowns can be caused by a lot of things: from leaks to faulty mail parts. Examine your boiler every day and pay attention to any changes – unusual noises, instrument readings, cracks, changes in flame or combustion products. In the table below, there is a list of the most common causes of malfunctions.
Problem | Solution |
---|---|
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 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-watcr 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. | |
E. Heavy oil fired unit - oil temperature below minimum settings. | |
4. Fuel valve interlock circuit not completed. A. Fuel valve auxiliary switch not enclosed. | |
No ignition | 1. Lack of spark. |
A. Electrode grounded or porcelain cracked. | |
B. Improper electrode setting. | |
C. Loose terminal on ignition cable; 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 elosed, slipped cam, defective switch. | |
B. Damper jammed or linkage binding. | |
4. Running interlock circuit not completed. | |
A. Combustion or atomizing air proving switches dcfcctivc or not properly set. | |
B. Motor starter interlock contact not closed. | |
5. Flame detector defective, sight tube obstructed, or lens dirty. | |
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. | |
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 linkage, 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. 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. | |
Shutdown occurs during firing | 7. Improper air/fuel ratio (lean fire). |
A. Slipping linkage. | |
B. Damper stuck open. | |
C. Fluctuating fuel supply. | |
1). Temporary obstruction in fuel line. | |
2). Temporary drop in gas pressure. | |
3). Orifice gate valve accidentally opened (heavy oil). | |
8. Interlock device inoperative or defective. | |
Modulating motor does not operate | 1. Manual-automatic switch in wrong position. |
2. Linkage loose or jammed. | |
3. Motor does not drive to open or close during pre-purge or close on burner shutdown. | |
A. Motor defective. | |
B. Loose electrical connection. | |
C. Damper motor transformer defective. | |
4. Motor does not operate on demand. | |
A. Manual/automatic switch in wrong position. | |
B. Modulating control improperly set or inoperative. | |
C. Motor defective. | |
D. Loose electrical connection. | |
E. Damper motor transformer defective. |