I have a hydromatic W698 which I bought in the early 1990's. It's still going strong but has started to make a funny rumbling noise when its draining, any ideas??
Thank you!!

Elspeth, December 2021

So when the drain pump runs it makes a noise.
What part of the machine runs only at that time?
Tough one.
Maybe there's a motor driven something that only runs when the machine is emptying.
Could it be a failing motor bearing.
Maybe there's some kind of pump that only runs when the machine is emptying. A long shot but it could be something in the pump or a bearing in the pump or its motor.
Wild guesses of course.

Dfgyte, December 2021