I too purchased the same unit. Either In the instruction booklet or on the unit itself... possibly on the BOTTOM of the unit...it DID say do not submerge this unit in water ... it will damage it. I use this Frother for Lattes and I like a lot of milk. So I fill the unit higher than the Latte mark on the inside of the milk chamber. When the unit comes on..it slops milk over the side and it tends to run down the sides. After several uses... all of a sudden this unit would not come on. No light comes on and no action. I let the unit sit for about 5 days and wiped it out carefully and all of a sudden it started a working as it should. I have no idea what happened...