In contrast to the heating current monitoring, where an external current transformer must be connected, additional hardware is checked during heating circuit monitoring to see if the heating circuit is OK.
With a control value of 100% (heating permanently switched on), the temperature rise is evaluated as a function of the control parameters. If the increase is too low or the temperature even drops, there is a heating circuit fault. The cause of this may be an open circuit in the actuator (e.g., contactor) or in the heating coil, but also a sensor suspended in the air.
This function can be activated for the controllers R2400, R2500, R2600 / 2601, R2700, R2900, R6000.