Thermador Cooktop Error Code Ci4

Ci4 indicates that the NTC thermistor for one of the induction inductors is either disconnected or has failed. The NTC thermistor is a temperature sensor the cooktop uses to monitor the heat level of each induction coil. When the control board cannot read a valid signal from this sensor, it disables the affected zone and displays Ci4. The technical service menu can be used to identify which specific inductor is generating the fault.

The cooktop disables the affected induction zone when Ci4 is active, specifically because it cannot monitor that burner's temperature without a functioning NTC sensor. You should not attempt to use the faulted zone. Other zones may still operate normally, but the underlying fault should be repaired promptly to restore full safe functionality.

Repair costs vary depending on the root cause. If the fix is simply reconnecting a loose NTC connector, a service call fee is the primary expense, typically in the range of $75 to $150. If the NTC thermistor itself needs replacement, parts and labor together generally fall in the range of $150 to $350, depending on your location and the technician's rates. A control board replacement, if needed, would cost more and could range from $300 to $600 or higher.

If the fault is simply a loose connector, a confident DIYer comfortable working inside an appliance can reseat the NTC wiring harness after disconnecting power. However, reaching the induction components typically requires disassembling the cooktop, and replacing a failed NTC thermistor or damaged wiring harness is more involved work. If you are not comfortable with appliance disassembly or electrical testing, a qualified technician is the safer choice.

Cycling power may temporarily clear the display, but the Ci4 code will return as soon as the control board attempts to read the NTC again during operation. A reset does not address the disconnected connector or failed thermistor that is causing the fault. The underlying hardware issue must be resolved for the error to be permanently cleared.