of the tank. most hot water heaters are good for no more than 10 years. corrosion and rust can be common and a good sign that a new hot water heater is needed in the near future.
fuel systems and storage are not something you want to mess around with. you want to make sure there is no leaking of oil or gas. i go into homes all the time that have gas leaks, you would be surprised how often. oil tanks rust from the inside out so you cant tell sometimes until it’s too late.
simply looking to see if the pump turns on when they need to. also, check to 