Waterpik sucks! I swear they're practising planned obsolescence. Two (2) devices just crapped out on me out of the blue. Both scarcely used! One portable, the other the normal, big one. Won't even comment on how these behaved when they worked (nothing remarkable, Panasonic is way better), just that Waterpik makes incredibly unreliable stuff, in my direct experience. How they are still on the market when there are so many alternatives now is beyond me. Won't ever buy again!