Whirlpool Microwave E13 Error Code — What It Means
E13 on a Whirlpool over-the-range microwave is a preheat failure code. The unit did not preheat correctly during a convection or preheat cycle. The fault typically points to trouble in the appliance control board or the associated wiring that runs between the board and the temperature-sensing circuit. A temporary control glitch can sometimes trigger the code, but if it returns after a power reset, you are looking at a real component or wiring issue that needs diagnosis and replacement.
Common Causes
- Failed appliance control board The main control board has a logic fault or failed output that prevents the preheat cycle from completing correctly.
- Damaged wiring or loose connectors The harness between the control board and the temperature sensor or preheat circuit is broken, corroded, or loose.
- Faulty temperature sensor or thermal sensing circuit On models that monitor preheat temperature, the sensor or its circuit has failed and cannot report valid readings to the control board.
- Heat-damaged harness connections Connector pins or terminals have been damaged by heat over time, creating intermittent or open circuits during preheat operation.
Step-by-Step Fix
- Turn off the circuit breaker that powers the microwave for one full minute, then turn it back on and wait another minute to see if the E13 code returns. This is Whirlpool’s published reset step for over-the-range microwave error codes.
- Note the operating mode when the fault appears. E13 is tied to preheat or convection cycles, not standard microwave cooking, so verify that the code only appears during those modes.
- Inspect all connectors at the control board and along the harness for looseness, corrosion, or heat damage. Reseat each connector firmly and look for discolored or melted plastic on the housing.
- Check harness continuity from the control board to the temperature sensor or thermal circuit. Use a multimeter to confirm that each wire in the harness has continuity and no shorts to ground.
- Test the temperature sensor if your model uses one for preheat monitoring. Compare the resistance reading at room temperature to the value in your model’s service manual or tech sheet. Do not guess at the specification.
- Replace the failed component once testing has identified the control board, harness, or sensor as the root cause. Component replacement is the repair, not adjustment or cleaning.
- Run a preheat test cycle after the repair to confirm that the microwave completes the cycle without throwing E13 again.
Parts Often Needed
| Part | Notes |
|---|---|
| Appliance control board (main PCB) | Amazon | Order by your exact model number. The control board is the most common E13 failure. |
| Wiring harness or connector kit | Amazon | If inspection shows heat damage or broken wires. Match the part number to your microwave model. |
| Temperature sensor (preheat sensor) | Amazon | Only needed if your model uses a sensor for preheat monitoring and testing confirms it is out of spec. |
When to Call a Pro
Call a qualified appliance technician if the code returns after a breaker reset, or if you are not comfortable working with live 120 VAC circuits and control boards. Diagnosis requires a multimeter, the model-specific service manual with sensor resistance tables, and safe disassembly of the microwave cabinet. Misdiagnosis can lead to unnecessary part replacement and wasted money, and working inside an over-the-range microwave without disconnecting power and discharging capacitors carries a serious shock hazard. A technician will have the correct specs and tools to pinpoint whether the control board, harness, or sensor is at fault.