I can't think of any reason the typically IR-receiving sensors in most automated bathroom appliances wouldn't also be able to sense a vampire. Vampires might have no reflection, but they are solid, physical beings, which should be able to block or reflect a beam of IR light, same as any normal human.
I do wonder, though, whether the nature of their flesh might interact differently with the capacitive-touch-sensors associated with most modern smart phone screens. Imagine being a vampire and not being able to make a phone call, or check the weather in Transylvania next Tuesday.
I suppose they're already accustomed to not being able to take selfies, so no big deal on that front.