Fault 1: The digital display does not work. Check that the air switch is closed and the control circuit is intact.
Fault 2: The heater temperature does not rise. Check if the fuse is intact and is the pipe heater damaged?
Fault three: three-phase unbalance. Check if the three-phase incoming voltage is out of phase. Open the pipe heater junction box and use a multi meter to check if the single heating element is open.
Fault 4: The insulation of the pipeline electric heater is reduced. Generally, it is caused by moisture entering the inside of the heating pipe. Remove the heater core and let it dry in the oven. In addition, it is also possible to blow the heating tube with hot air or blow the heater with a fan, and then turn on the heater, and use the heating tube to generate heat to generate moisture.