Do you like tomatoes? Personally, I can’t stand them. I find the texture strange, the taste unpleasant, and the water they emanate that gets into surrounding food items disgusting. They are not all bad, though. I do love some of the tasty byproducts that come from tomatoes. I am of Italian descent after all, so, besides ketchup, I do enjoy the various tomato products that go into pasta sauces and gravy (note: you might have to be very Italian to understand the gravy reference).
So, what do my random thoughts about tomatoes have to do with water heaters? Well, there has been some debate as to whether a tomato is a fruit or a vegetable. To me, it doesn’t matter because how they are classified is not going make me dislike them any less. But to some people, it matters. Whether a tomato is a fruit or vegetable depends on how its attributes match or don’t match the attributes associated with fruits and vegetables. In the plumbing world, properly identifying whether a water heating appliance is technically a water heater or something else works the same way. By looking at what the appliance does, and often what it doesn’t do, this determination can be made and, thus, the proper code requirements can be applied to it.