Wascomat Washer Error Code 31: Heat Sink Too Hot
Code 31 means the sensor on the motor control cooling flange passed 90 C. The motor control set the code to protect its power transistors. Let the machine cool and check that the drum turns freely, and have a technician test the motor and control if it returns.
High: the motor control stops the drive to protect itself, and repeated overheating can damage it.
What does Wascomat error code 31 mean?
The motor control carries power transistors that get warm as they drive the drum motor. An NTC sensor on its cooling flange watches the temperature. When it exceeds 90 C, the motor control sets ERROR 031 / HEAT SINK TOO HOT to protect the transistors. The manual names two causes. One is a stiff drum combined with intensive use and a high ambient temperature, since the control then works harder and sheds less heat. The other is a motor problem, such as sticking bearings or a short in the windings. The service steps are to make sure the drum turns easily, check the code 31 counter and the last 8 motor control error codes, run a 90 C normal program with a load while measuring motor and motor control temperature, and replace the defective part.
Affected models and control systems
Wascomat washer-extractors W465H-W4300H, W475S-W4330S and W475N-W4330N with the Compass Control and its motor control (MCU).
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
- ERROR 031 / HEAT SINK TOO HOT appears after heavy use
- The drum stops and the machine will not restart until it cools
- The laundry room is hot and the machine runs back-to-back loads
- The code returns sooner each time the machine is used
Possible causes
Listed in Wascomat's documentation
- Stiff drum with intensive use and high ambient temperature
- Motor problem (sticking bearings, short in 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.
- Lint packed around the cooling vents of the control area that holds heat in
- A room with poor ventilation, where summer heat laundries pushes the cabinet temperature up
Safe checks before calling for service
- Switch the machine off and let it cool for at least 30 minutes.
- Turn the drum by hand with the power off, if the door allows, and note whether it feels stiff or grinds.
- Clear lint from the area around the machine and make sure the room is ventilated.
- Restart with a lighter load. If the code returns, note how many loads ran before it appeared, and call us.
How a technician diagnoses error code 31
- Read the code and check the code 31 counter and the last 8 motor control error codes.
- Make sure the drum turns easily and check the bearings and belts.
- Run a 90 C normal program with a load and measure the temperature of the motor and the motor control.
- Compare the readings with the sensor reading on the cooling flange.
- Check the motor windings for a short and the bearings for roughness.
- Replace the defective motor or motor control based on the measurements.
- Running a loaded 90 C test and measuring temperatures means working near hot parts and moving machinery.
- The motor control and its mains supply are inside the cabinet.
- Telling a hot room from a failing motor needs temperature measurements and the counters.
How error code 31 differs from similar codes
Code 32 MOTOR TOO HOT is the motor-winding version of the same idea, while code 31 is reported from the motor control's own cooling flange.
Technical reference
- Maker documentation
- Wascomat owner support
- Edition
- 438 9228-61/EN, 2011.08.25
- Models / control
- Compass Control W-series washer-extractors (MCU motor control)
- Section
- Troubleshooting, Description of error codes and causes (manual pp. 108-138)
- 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 Wascomat washer error codes
Is it safe to restart right after code 31?
Let the machine cool first. Restarting while hot can trigger the code again and stress the transistors.
Is it the room or the machine?
It can be either. A hot room and heavy use can cause it, but a stiff drum or failing motor needs a technician.
What does the counter tell you?
The manual lists a code 31 counter and the last 8 codes, which show how often and when the overheating occurred.
Need help with Wascomat error code 31?
A technician confirms the cause on site and gives you the price in writing before any work starts.