Dual protection method of heating device and heating device using same

The invention discloses a dual protection method of a heating device and a heating device using the same, and belongs to the technical field of heating control, the method comprises the following steps: S1, detecting whether the temperature of a heating terminal reaches a set temperature; if not, executing the step S2; s2, judging whether the duration of the heating signal output by the programmable controller is less than N seconds or not, and stopping for X seconds after continuously working for M seconds, and if not, executing the step S3 and the step S4; s3, if the programmable controller does not output the heating signal, triggering an alarm program, and if the programmable controller uninterruptedly outputs the heating signal, triggering a time relay to start; and S4, judging whether the time relay is disconnected, if so, triggering an alarm program, and if not, disconnecting the electric connection loop of the heating terminal through the time relay. The heating device uses a dual protection method of