Is the water inside the machine dirty and smelly?
If it is, it may be because during the installation, you connected the grey washing machine waste hose to your sink. If so, it is important that the hose is fitted higher than the sink bowl. Is your machine next to the sink? check in the cupboard, if the hose is pointing straight down then it is possible that each time you empty the sink some of this water is flowing down into your washer. Check that it travels up above the sink and if not adjust it so that it is fitted as shown in this diagram:
to stop the machine filling up from your sink fit the waste hose as shown by the red arrow