8 Common Box Type Tempering Furnace Faults & Troubleshooting Solutions

Long-term high-load operation and irregular operation will cause various mechanical and electrical faults of the box type tempering furnace, reducing production efficiency and causing workpiece scrap. Most small and medium-sized heat treatment enterprises lack professional maintenance personnel, resulting in delayed fault handling. This article summarizes 8 high-frequency faults of industrial tempering furnaces and provides operable solutions for on-site operators.

1. Slow Heating Speed, Cannot Reach Set Temperature

Fault Causes: Unstable power supply voltage, damaged heating resistance wire, aging door sealing strip, blocked exhaust duct and serious heat loss. Solutions: Detect three-phase power supply balance, replace aging heating elements, update high-temperature resistant sealing gaskets, clean internal impurities of exhaust pipes regularly to ensure smooth hot air circulation inside the furnace.

2. Inaccurate Temperature Display and Large Data Fluctuation

Fault Causes: Thermocouple installation offset, mismatched thermocouple and controller graduation, short circuit of compensation wire, aging temperature control instrument. Solutions: Adjust the thermocouple probe to the effective working area of the furnace chamber, replace matching accessories, reset instrument parameters, and replace the controller if it is severely damaged.

3. Heat Leakage from Furnace Door

Fault Causes: Sealing strip aging and deformation, loose fastening screws, deformed furnace door caused by collision. Solutions: Replace the integral high-temperature sealing strip, fine-tune the door screw to narrow the gap, manually correct slightly deformed furnace doors.

4. Equipment Fails to Start and Control System No Response

Fault Causes: Power failure, blown fuse, tripped air switch, damaged door travel protection switch. Solutions: Inspect external power lines, replace fuses with the same specification, reset the air switch after eliminating short-circuit risks, and calibrate the travel protection switch.

5. Abnormal Noise During Heating

Fault Causes: Loose internal heating elements, foreign matters in the furnace chamber, abnormal operation of cooling fan. Solutions: Power off the equipment to fasten loose parts, clean residual workpiece debris, overhaul or replace the cooling fan.

6. Workpiece Oxidation Serious After Tempering

Fault Causes: Poor internal sealing, excessive moisture in the furnace, no protective gas device. Solutions: Enhance overall sealing performance, complete drying treatment before production, and install nitrogen protection accessories.

7. Tripping During Heating Process

Fault Causes: Internal line short circuit, damp electric box, overload of heating elements. Solutions: Dry the electric control box, sort out messy internal lines, check and replace short-circuited heating wires.

8. Uneven Temperature Inside Furnace Chamber

Fault Causes: Unreasonable workpiece loading method, aging local heating elements, blocked hot air duct. Solutions: Optimize loading layout to avoid dense stacking, replace damaged heating wires, clean ventilation ducts regularly.

Conclusion

Regular daily maintenance can reduce more than 80% of common faults of box type tempering furnaces. If you encounter complex faults that cannot be solved manually, please contact our after-sales technical support team to obtain remote guidance and door-to-door maintenance services.