How do I eliminate vacuum forming in a BOSCH Maxx WFL1200 drain system?

Hi,

For the past couple of weeks, we’ve been battling with our washing machine’s draining / spinning cycles (Irrespective of the program and/or temperature it’s on). As soon as the program reaches the draining / spinning cycle, the machine stops and the control light flashes. AS PER THE USER MANUAL, the concerns seems to be a blocked drain hose caused by fluff producing items which were washed on a high temperature.

I have checked all hoses and cleaned everything I could as per the user manual. I have also removed the drain pump and verified that there’s nothing obstructing the water to flow towards the impeller. As soon as I fit the pump again (and the plastic ball inside moves freely), the machine washes successfully for approximately 3-5 washes until the concern repeats itself. What I have determined though, is that the plastic ball inside the drain “pump” is stuck in an upwards position EACH time this occurs. It’s as if the draining system from the drum to the pump forms a vacuum and sucks the plastic ball towards the drum which fills the tube and triggers the sensor to indicate “a blocked drain pipe”.

In order for the water to flow without obstruction, the plastic ball should be in a downwards position to allow the water to flow towards the impeller. I have also verified and determined that the system from the impeller onwards, operates well (tested by inserting water through the hose exit in reverse and then spinning it)..

Any suggestions will be HIGHLY appreciated.


Many thanks in advance!