Whirlpool Dryer Error Code D18

D18 indicates an Axial Probe Fault, meaning the axial thermistor has been reading a temperature outside its normal operating range for more than 30 seconds. This typically points to an open or shorted condition in the thermistor probe or its associated wiring. The control board triggers this fault to prevent the dryer from operating with unreliable temperature data.

It is not recommended to continue running the dryer while D18 is active. The axial thermistor is part of the temperature monitoring system, and operating without reliable sensor data could allow the dryer to run outside safe temperature limits. Discontinue use until the fault has been diagnosed and corrected.

Repair costs vary depending on what has failed. A replacement thermistor probe is generally an inexpensive part, typically in the range of $15 to $50 for the component itself. If professional labor is required, total repair costs including diagnosis and installation can range from $100 to $250 or more depending on your location and service provider. Wiring repairs or a control board replacement would push costs toward the higher end of that range.

The D18 fault is designed to auto-clear if the axial thermistor returns to a valid operating range on its own, without requiring a manual reset. However, if the underlying problem such as a broken wire, shorted probe, or bad connector is still present, the fault will return quickly. A reset alone will not fix a physically damaged sensor or wiring.

Start by inspecting the axial thermistor probe and its wiring harness for visible damage, then check all connectors for corrosion or loose pins. Measure the resistance across the thermistor terminals to confirm whether the probe is open, shorted, or within its normal range. If the probe has failed, it will need to be replaced. If wiring or connectors are damaged, repair or replace those components.