Once, when we had a Miele Tech service our W 4840, he stated that using detergents that fill the entire drum with suds will cause the drum to overflow and fill the bottom pan of the washer. Sitting in that pan is the float switch that will stop the cycle and run the drain pump to evacuate the pan. You are likely using the wrong detergents and too much detergent. Below are excerpts from the service manual:

2 Function

2.1 Float switch (B8)
A float switch (B8) is located in the sump of the appliance housing. If water leaks into the sump, float switch (B8) is activated. The program and with it the water intake are stopped, and the fault message Waterproof is issued.

3.8 Display indicates: Waterproof, shut off faucet

Symptom
In the operating mode, the display shows: Waterproof reaction.
The LED “check water intake” and the LED “check water drain” flashes rapidly. The program is stopped, the water intake valve is closed, and the drain pump is switched on for 120 seconds.
Waterproof system (WPS), refer to 040 2.1 Float switch (B8).

Cause
The appliance has a leak, there is water in the sump pan, and the float switch (B8) has responded.

Remedy
• Shut off the water faucet.
• Remove the water from the sump/drain pan.
• Locate the leak and fix it.

*Illustration is the property of Miele.