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Error code · Wascomat · Washers

Wascomat Washer Error Code 42: MCU Parameter Set Missing

Code 42 means the motor control (MCU) holds no motor parameter set. Switch the machine off for at least 30 seconds so the MCU fully resets, then switch it on. If the code returns, a technician checks the timer software version, and if it remains, the MCU is replaced.

Medium · inspection needed

High: the motor control has no parameter set, so the washer will not run until it is restored.

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Code
Error code 42, NO PARAMET. SET IN MCU
Maker
Wascomat
Equipment
Washers
Applies to
Compass Control W-series washer-extractors W465H to W4300H (MCU motor control)

What does Wascomat error code 42 mean?

Each Wascomat machine size needs its own motor parameters so the motor control drives the drum correctly. The motor control (also called the MCU or inverter) stores that parameter set. At power-up, the timer normally writes the parameter set digit defined in the fixed config into the MCU. If the MCU holds no parameter set, the control shows ERROR 042 / NO PARAMET. SET IN MCU and does not run the drum. The manual lists no individual causes and gives a clear order of steps. First, switch the machine off for at least 30 seconds so the MCU fully resets, then restart. If the code returns, update the timer software. If it still remains, replace the MCU. The order matters, since a simple reset or a software update is far cheaper than a new motor control.

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 042 / NO PARAMET. SET IN MCU appears at power-up
  • The drum will not turn and the washer stays stopped
  • The code returns after every restart
  • The code appeared after a power outage or board work

Possible causes

Likely causes — what usually sits behind error code 42 on this control. A technician confirms which one it is before any part is replaced.

  • A reset that was too brief, so the MCU did not clear fully before power came back
  • A timer software version that does not write the parameter set to the MCU at power-up

Safe checks before calling for service

✓ What an operator can do
  1. Switch the machine off at the disconnect and leave it off for at least 30 seconds.
  2. Switch it on again and see whether the code clears.
  3. Do not open the control cabinet or change settings.
  4. If the code returns, note the model, the serial number from the data plate and any recent power outage or board work, then call us.

How a technician diagnoses error code 42

  1. Read the code and confirm that it appears at power-up.
  2. Check the timer software version against the one the machine needs.
  3. Update the timer software if the version is out of date.
  4. Confirm the parameter set digit defined in the fixed config.
  5. Re-test power-up after the update and see whether the parameter set is written to the MCU.
  6. Replace the MCU only if the code remains after the update.
! Leave this to a technician
  • Software updates and fixed config values need the correct files and data for this machine size.
  • The MCU sits inside the cabinet with mains-level wiring.
  • Selecting the wrong parameter set can run the motor wrongly, so it is never guessed.

How error code 42 differs from similar codes

This meaning applies to the Compass Control. On newer controls such as the H7-130, a missing MCU parameter set is shown as 23:12 instead.

Technical reference

Document
Wascomat / Electrolux Compass Control service manual for W465H to W4300H, Error 42 "NO PARAMET. SET IN MCU"
Maker documentation
Wascomat owner support
Edition
438 9228-61/EN, 2011.08.25
Models / control
Compass Control W-series washer-extractors W465H to W4300H (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.

→Same maker

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Error code 42Questions about Wascomat error code 42
Can the washer run while code 42 is showing?

No. Without a motor parameter set the MCU will not drive the drum.

Does the 30-second wait matter?

Yes. The manual says to switch off for at least 30 seconds so the MCU fully resets before restarting.

Is code 42 the same on every Wascomat?

No. This page is for the Compass Control. The H7-130 control uses 23:12 for a missing MCU parameter set.

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