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. |