Electrolux Washer Extractor Error Code 31: Heat Sink Too Hot
Error code 31 means the motor control measured more than 90 C on the NTC at its cooling flange, next to the output transistors. Let the machine cool and make sure the drum turns easily. If it returns, a technician should check the motor, the drum and the motor control history.
High: the motor control shuts down to protect itself, and repeated overheating can damage it.
- Code
- Error code 31, HEAT SINK TOO HOT
- Equipment
- Industrial laundry
- Applies to
- Compass Control washer-extractors (CPU board, motor control, DLCU)
What does Electrolux Professional error code 31 mean?
The motor control sits close to the motor and carries the power transistors that drive it. An NTC sensor on the cooling flange next to those transistors measures how hot the board is getting. If that reading goes over 90 C, the motor control shuts itself down to protect the transistors and the CPU board shows ERROR 031 / HEAT SINK TOO HOT. A drum that is stiff to turn, heavy use and a hot room make the motor work harder and push heat into the motor control. The manual also lists a motor problem such as sticking bearings or shorted windings. Technicians read the error-code counter for 31 and the last 8 motor-control codes to see how often it happened. Staff notice the drum stop in the middle of a busy shift and start again after a rest.
Affected models and control systems
This applies to the W465H-W4300H, W475S-W4330S and W475N-W4330N washer-extractors, Type W3..., with the Compass Control. The 90 C limit applies to the NTC on the motor control's cooling flange.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- Display shows ERROR 031 / HEAT SINK TOO HOT
- Machine stops during a heavy cycle
- Machine runs again after cooling
- Laundry room is warm and machines run back to back
Possible causes
Listed in Electrolux Professional's documentation
- Stiff drum with intensive use and high ambient temperature
- Motor problem such as sticking bearings or shorted windings
Other likely causes — what usually sits behind error code 31 on this control. A technician confirms which one it is before any part is replaced.
- Cooling air path around the motor control blocked by lint
- Drive belt or bearing drag making the motor draw more current than normal
- Thermal paste or mounting of the transistors loosened on the cooling flange
Safe checks before calling for service
- Let the machine rest and cool before trying again.
- Turn the drum by hand with the machine off and power isolated if you can reach it safely, and note whether it feels stiff.
- Make sure the room is ventilated and lint is not packed around the machine.
- Note how many cycles ran before the stop and the room temperature, then call us.
How a technician diagnoses error code 31
- Read the code and check the error-code counter for 31 and the last 8 motor-control codes.
- Make sure the drum turns easily.
- Run a 90 C program with a load and measure the motor and motor control temperatures.
- Check the motor for sticking bearings and shorted windings.
- Replace the defective part after the test.
- Temperature measurements on the running motor and motor control are taken by a technician on a live machine.
- The motor control history is read through the service program.
- Overheating drive electronics can fail permanently, so the cause needs a proper diagnosis.
How error code 31 differs from similar codes
Code 31 is the motor control board's own heat limit; code 32 is the motor winding temperature.
Technical reference
- Maker documentation
- Electrolux Professional owner support
- Edition
- 438 9228-61/EN, 2011.08.25
- Models / control
- Compass Control washer-extractors (CPU board, motor control, DLCU)
- Section
- Troubleshooting, printed p.125 (Error codes)
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Electrolux Professional industrial laundry error codes
Can I restart after it cools?
Yes, but if the drum is stiff or the room is hot it will likely stop again.
Does this mean the motor is bad?
Not always. The manual lists a stiff drum with heavy use and high ambient temperature first.
How do you know how often it happened?
The technician reads the counter for code 31 and the last 8 motor-control codes.
Need help with Electrolux Professional error code 31?
A technician confirms the cause on site and gives you the price in writing before any work starts.