The boiler controller is the core of the safe operation of the boiler, but it is inevitable to encounter various problems in daily use. Understanding these common problems and their causes will help users troubleshoot in time and ensure stable operation of the boiler. The following are several common problems of industrial boiler controllers summarized by Henan Rentai based on years of experience and a brief analysis as follows:
Water level control failure: Too high or too low boiler water level will trigger an alarm or even shut down, which is one of the common problems. If the boiler often has low water level alarms or even wrong shutdowns, the possible reasons include lack of water in the heating/water supply system, poor grounding, water level sensor failure, or even controller misjudgment of water level. For example, when the water level sensor fails or the connection is loose, the controller may misjudge that the water level is too low and issue an error alarm. Users should regularly check the boiler water supply system to ensure that there is sufficient water, the water level sensor is clean and the connection is reliable. If the water level sensor or controller module is damaged, it needs to be replaced and repaired in time.
Ignition and combustion problems: It is also common for the boiler to fail to ignite or accidentally shut down during operation. The causes of this type of problem are more complicated. For example, the controller does not output an ignition signal, the high-voltage ignition wire is loose, the ignition transformer fails, and the ignition electrode gap is improper, which can lead to unsuccessful ignition. In oil or gas boilers, poor fuel supply (blocked fuel injector, insufficient gas pressure) or improper air supply (inappropriate damper opening) may also cause flameout. For this type of problem, first check whether the fuel supply and fan damper are normal; secondly, check whether the controller's ignition output is working (such as the flame detector indication status); if necessary, replace the damaged ignition element and adjust the ignition electrode spacing. After eliminating the hardware failure, if it is still difficult to ignite, ask professionals to check whether the controller's combustion control program parameters need to be adjusted. Abnormal sensor signal: The boiler control system relies on a variety of sensors to obtain data such as pressure, temperature, and water level. Once a key sensor fails or reads inaccurately, the controller will make an incorrect judgment. For example, pressure sensor drift may cause the controller to misjudge the boiler pressure, and high temperature sensor failure may cause unnecessary over-temperature alarms. It is also common that the water level electrode is scaled or aged to cause false water level signals. To deal with such problems, sensors need to be calibrated and maintained regularly: clean water level electrodes and probes, calibrate pressure and temperature transmitters, etc. Once the sensor output is abnormal or exceeds the calibration cycle, the sensor should be replaced in time. High-quality sensors and regular maintenance can significantly reduce such failures.
Controller hardware failure: Although industrial controllers such as PLC are designed to be reliable, hardware problems may also occur after long-term operation. For example, the burnout of the output relay of the controller will cause the corresponding water pump and fan to fail to start; damage to certain I/O channels will manifest as the inability to read the switch quantity or output control signals; even the aging of the internal electronic components of the controller may cause the program to run abnormally or freeze. If the controller hardware failure is suspected, first check the indicator light status of the relevant modules in the control cabinet to see if any module is offline or has a fault indication; for modules that are determined to be damaged, replacement is the fastest solution. It is worth noting that the control systems provided by Henan Rentai all use branded genuine hardware, and are replaced and repaired free of charge during the warranty period, reducing users' worries about hardware failures.
Control program or logic problems: Sometimes there is no hardware damage to the boiler controller itself, but operation problems may also occur due to imperfect control logic or improper parameter settings. For example, poor PID parameter settings may cause excessive fluctuations in boiler pressure and temperature regulation or slow response; loopholes in interlock protection logic may cause false alarms or accidental shutdowns. Some old boilers were renovated with the original program, which may not be optimized for the new site conditions. In this case, the controller program needs to be checked and optimized. We recommend that professional technicians adjust the control parameters and improve the interlock protection logic based on the actual operation data of the boiler. Henan Rentai has rich experience in this area. We can optimize the control scheme for different boiler systems and improve the control quality. If the user finds that the boiler operation is often abnormal but the hardware problem is ruled out, it is likely that adjustments and upgrades will be made to the control logic.
Power supply and connection problems: The electrical environment of the industrial site will also affect the performance of the boiler controller. For example, abnormal power supply voltage of the control cabinet (too high, too low or instantaneous power failure) will cause the controller to reset or even damage; loose terminals or aging cables will cause intermittent signals, causing the controller to malfunction. Vibration in the boiler room may also loosen some electrical connections. Such problems often manifest as intermittent faults without obvious patterns. The preventive method is to tighten and check the wiring terminals in the control cabinet during daily maintenance to ensure that the power supply and signal lines are connected reliably; configure the control cabinet with a voltage-stabilized power supply or an uninterruptible power supply (UPS) to avoid the impact of AC power fluctuations on the controller. When suspicious, you can use a multimeter to measure the voltage at each key point and check whether the terminals are loose and hot. Maintaining good electrical connections and stable power supply can avoid many inexplicable control failures.
Improper operation and maintenance: Human factors are also one of the important causes of boiler control system problems. Incorrect operations, such as arbitrary modification of controller parameters and frequent manual intervention in automatic control, may cause system operation disorder or even trigger protection shutdown. In addition, if there is a lack of daily maintenance of the boiler and control system, such as water treatment that fails to pass the scale formation of the water level probe, long-term uncleanness of the burner that makes flame detection difficult, and dust accumulation on the control cabinet filter that causes overheating, it will indirectly cause control problems. In this regard, we recommend that boiler operators strictly abide by the operating procedures and do not arbitrarily change the control parameters set at the factory; key steps such as starting and stopping the furnace should be executed according to the process to avoid misoperation. At the same time, the boiler and control system should be regularly maintained according to the manufacturer's recommendations, such as cleaning the sensor probe, checking the flexibility of valves and actuators, and cleaning the dust from the control cabinet vents. Good operating habits and adequate maintenance can minimize the probability of boiler controller failure.
Summary: When a boiler controller fails, do not panic or operate blindly. You should judge which of the above problems it belongs to based on the fault phenomenon, and then take corresponding measures to deal with it. For example, if there is an abnormal water level or pressure alarm, first check the sensor and the actual equipment situation; if the controller does not respond, consider the power supply and hardware problems. For complex faults or problems that cannot be handled by yourself, it is recommended to contact professional technicians in time for troubleshooting. We, Henan Rentai, provide customers with lifelong technical service support. Whether within or outside the warranty period, we will assist you in diagnosing and solving difficult problems in the boiler control system to ensure the long-term safe and reliable operation of your boiler. For more information, please contact Henan Rentai Electric immediately: Tel: 17638563962 / 0371-56520104 and Email: info@hnrentai.com.