If the machine works fine otherwise, then it is most likely a fault on the drainage pump side. First check that the drains are not blocked: i.e. kinked drain hose, or channels blocked with lint, paperclips etc.
If there's no blockage then the drain pump has probably failed. This will tend to be indicated if you hear a buzzing sound/vibration when the machine is in draining cycle.
The Siemens machines share their parts with Bosch and Neff machines. A replacement part from a dealer will be around £50 or more. You can obtain original parts on Ebay for around £45, or much cheaper generic copies for around £12.
It's quite easy to replace the units but best done with two people as these machines are quite heavy and cumbersome to manouver.
John Michael Richards, November 2008
