There could be a few reasons your sterilizer is beeping and/or flashing:
Model: WA-8810N, WA-8811N
1. Safety first! The WABI BABY will beep to let you know that the bottle chamber has been placed incorrectly.
Make sure it's not just the chamber being placed on the base unit, in some rare case, the safety tab may be still not being pushed down all the way. Place the accessory basket and lid on top, and it should solve the issue.
2. No water being added for the sterilization cycle.