As a core equipment in fields such as chemical synthesis and biological cultivation, the stable operation of a constant temperature reaction bath directly affects the accuracy of experimental results. The following provides systematic troubleshooting and solutions for typical fault phenomena:
1、 Temperature runaway fault
Symptom 1: The set temperature cannot be reached
⊙ Troubleshooting path: Prioritize checking whether the liquid level of the heating medium (water/oil) is below the low mark line → Supplement the thermal conductive silicone oil to the specified liquid level; Observe the surface scaling of the heating tube. Mild scaling can be cleaned by soaking it in a descaling agent, while severe blockage requires disassembly and replacement; Detect the output voltage of the solid-state relay. If there is no heating action when powered on, the relay module needs to be replaced.
Attention: Do not disassemble the heating tube without emptying the medium to avoid residual liquid leakage and damage to the circuit board.
Symptom 2: Actual temperature exceeds the set value (overheating)
Key checkpoint: whether the temperature control sensor probe is detached from the bath or wrapped in impurities → re fix the sensor and clean the probe; PID parameter setting error leads to excessive integration → Enter the menu to restore the factory PID parameters and reset the self-tuning; If the over temperature protection is not triggered, immediately cut off the power and check if the thermocouple connection wire is short circuited.
Symptom 3: Severe temperature fluctuations
Key reason: Decreased efficiency of the circulating pump → Disassemble and inspect whether the impeller of the centrifugal pump is stuck by impurities, and clean the filter screen cover; When the temperature difference in the external environment is too large, an external insulation cover should be used; Check if the speed of the mixing motor is normal. If it is too low, it may cause local temperature differences.
2、 Abnormal circulation system
Abnormal noise/idling of water pump
Immediately stop the pump and check the liquid level in the storage tank to prevent gas binding; Disassemble the pump head to remove debris from the suction inlet; If the sealing ring is worn and causes leakage, it is necessary to replace it with an O-ring of the same specification; After long-term disuse, it is necessary to manually turn the wheel to confirm smooth rotation before starting.
Poor cooling effect (limited to low-temperature models)
→ Check if the working current of the compressor is normal; The dust accumulation on the condenser fins can be cleaned with a soft bristled brush; Insufficient refrigerant is manifested as low high pressure, requiring professional personnel to supplement R404A environmentally friendly refrigerant; Frost formation on the expansion valve indicates that the drying filter is clogged and needs to be replaced as a whole.
3、 Display and control system malfunction
Digital tube garbled/button malfunction
→ Try shutting down and restarting to eliminate temporary interference first; Continuous abnormalities are often caused by moisture on the motherboard, and a hot air gun can be used to dehumidify the circuit board; If individual buttons fail, measure the on/off status of the corresponding touch switch, and those with poor contact need to be welded and reinforced.
Alarm code analysis
E01 code usually indicates a temperature sensor open circuit, check if the wiring terminals are loose; E03 represents the triggering of over temperature protection, and the parameters need to be adjusted after the system automatically resets; Detailed error information can be found in the equipment manual's fault comparison table.
4、 Key points of daily maintenance
Quarterly maintenance: replace the circulating medium filter element; Calibrate temperature sensor (compared to standard platinum resistance); Test the equipment status during extreme high and low temperature operation.
Annual maintenance: Thoroughly clean the condenser fins; Inspect electrical safety performance (insulation resistance>2M Ω); Lubricate the mechanical transmission parts.
Preventive suggestion: Establish operation logs to record daily temperature curves; Configure a regulated power supply to prevent voltage fluctuations; It is strictly prohibited for corrosive liquids to come into direct contact with metal parts.
Through graded diagnosis and targeted treatment, most faults can be located and resolved within 30 minutes. It is recommended to contact the original factory engineer for complex electrical faults to avoid secondary damage caused by self disassembly. Regular maintenance can reduce the sudden failure rate by over 60% and ensure that the experimental progress is not affected.