They replaced it on Monday so all seems well now. (You never realize you much you take hot water for granted until you're standing with under cold water with a head full of shampoo. /o\ Although on the bright side it did let me put off doing dishes for a day. \o/)

Dogs have their own special heart attacks though, mostly revolving around "OMG, did you eat that? Why did you eat that? HOW did you eat that?!"