Brand: Model Number:WED9400SB0 Main Symptom:NO HEAT What happens & when:
Whirlpool duet electric dryer WED9400SB0. Unit turns on but heating element does not. Put the dryer in diagnostic mode. Got error code F 25. Shorted inlet thermistor. Ordered and installed new unit. Same result. Went to control board and unplugged inlet thermistor wiring harness from control board. Tested wiring and thermistor at 52K ohms. If the wiring and the thermistor are not testing shorted, does that just leave me with the control board being the problem?
Error Code (if any):F25
Parts or tests already tried:
Photos / video link:
Based on everything you’ve tested, I would not replace the control board just yet. An F25 error indicates the control is seeing the inlet thermistor circuit as shorted (very low resistance), but your measurement of about 52 kΩ indicates the thermistor circuit itself is not shorted.
Here’s how I would narrow it down.
1. Clear the Stored Error Code
The Duet dryers store fault codes until they are cleared.
Enter diagnostics.
Clear the stored codes.
Exit diagnostics.
Run the dryer for a few minutes on a heated cycle.
Re-enter diagnostics and see if F25 returns.
If it does not return, you may have simply been seeing the old stored fault.
2. Verify the Thermistor Resistance
At room temperature (around 70-77°F), the inlet thermistor should measure approximately:
50–55 kΩ at 77°F
Your reading of 52 kΩ is right where it should be.
Since you measured this through the wiring harness, that also tells us the harness has continuity.
3. Inspect the Harness Carefully
Even though the resistance checks correctly:
Inspect both connector plugs for corrosion or moisture.
Look for terminals that have spread apart and are not making good contact.
Follow the harness looking for insulation rubbed through against the cabinet.
An intermittent short can trigger F25 even though the circuit measures correctly with the dryer unplugged.
4. Check the Heating Circuit
Since your primary complaint is no heat, don’t focus solely on the F25 code. Verify the rest of the heating circuit.
With the dryer unplugged, test for continuity through:
Heating element
Thermal cut-off
High-limit thermostat
Thermal fuse
Motor centrifugal switch (heat contacts)
An open thermal cut-off or element is far more common than a failed control board.
5. Verify Incoming Voltage
Please include a Live Power Warning anytime you’re checking live voltage.
Live Power Warning: These tests are performed with the dryer energized. Use extreme caution to avoid electric shock. If you’re uncomfortable working around live voltage, do not perform these tests.
A Duet dryer can run normally on 120 VAC but produce no heat if one leg of the 240 VAC supply is missing.
Measure:
L1 to L2: approximately 240 VAC
L1 to Neutral: approximately 120 VAC
L2 to Neutral: approximately 120 VAC
If either leg is missing, the drum will tumble but the heater will never energize.
6. If Voltage and Heating Components Test Good
If all of the following are true:
240 VAC is present
Heating element is good
Thermal cut-off and thermostats are good
Thermal fuse is good
Motor centrifugal switch is closing
Thermistor measures about 52 kΩ at the control connector
Wiring harness is intact
F25 immediately returns after being cleared
then the electronic control board becomes the most likely failed component.
One Question
When you measured the 52 kΩ, was that at the control board connector with the harness plugged into the thermistor, or were you measuring the thermistor directly at the sensor? Also, have you verified 240 VAC at the terminal block while the dryer is running? Those two answers will help determine whether the issue is truly the control board or if there’s still another component in the heating circuit to check.
To enter diagnostics and clear the stored error codes on your Whirlpool Duet Dryer (Model WED9400SB0):
Enter Diagnostic Mode
Make sure the dryer is in Standby Mode:
Plugged in.
All indicator lights are OFF.
Within 5 seconds, press the following button sequence:
More Time
Less Time
More Time
Less Time
If entered successfully:
All console LEDs will illuminate.
The display will show “88”.
Any stored error codes will then be displayed.
View Stored Error Codes
If multiple codes are stored, press the same button used as the 3rd button in the entry sequence (in this case, More Time) to scroll through each stored code.
Codes are displayed one at a time.
Clear Stored Error Codes
On this generation of Duet dryers, fault codes cannot simply be erased with a button press. The codes are intended as a history to aid in diagnosis and typically clear automatically after the underlying problem is repaired and the dryer completes successful operation. The diagnostic mode itself is primarily for viewing stored codes and testing components.
Exit Diagnostic Mode
Press Pause/Cancel (or Power on some versions), or
Unplug the dryer for a few seconds.
If you let me know which error code(s) you find (for example F25, E1, E2, etc.), I can walk you through the specific troubleshooting steps for that code.
Live Power Warning: These tests are performed with the dryer energized. Use extreme caution to avoid electric shock. If you’re uncomfortable working around live voltage, do not perform these tests.
240 VAC is present