Disclosed are systems, devices, and methods for operating an electrosurgical generator, comprising an RF output stage configured to output an electrosurgical waveform through at least one pair of electrodes, sensing circuitry configured to measure an impedance between the at least one pair of electrodes configured to grasp tissue, and a controller configured to determine whether the impedance of the tissue disposed between the at least one pair of electrodes exceeds an impedance threshold, determine whether a change in the impedance is greater than an upper change in impedance threshold, and output an alarm indicative of the at least one pair of electrodes being at least partially open based on at least one of the impedance exceeding the impedance threshold or the change in impedance exceeding the change in impedance threshold.
