Please take a look at these 2 gas water heater pictures. In the first picture you can see rusting along the bottom exterior. In the second picture you can see about 1/4" of rust flakes on the top of the burner and that the bottom of the water tank is rusted. I’m trying to figure what to say about this. At a minimum the rust should be cleaned out and off of the burner (serviced). The water heater isn’t leaking. Should I say that this water heater should be replaced? Or that a plumber evaluate it? It’s 13 years old and still works, but looks like it could spring a leak any day now. Thanks for your help.