Most no-hot-water calls on a gas heater come down to a small part: the thermocouple or flame sensor, the pilot assembly, the igniter, or the gas control valve. On an electric heater it is usually a heating element or thermostat. These are real repairs, and on a tank that is otherwise sound they are the right call.
The tank itself is a different story. Water heaters are lined steel tanks protected by a sacrificial anode rod. Once the anode is used up, the steel starts to corrode, and a leak from the body or bottom seam of the tank means the tank is done. Rusty hot water, rumbling from heavy sediment, and an age past roughly 10 to 12 years all point the same way.
We give you the honest version on site: what failed, what the repair costs, and whether putting money into this tank makes sense at its age. If replacement is the better value, we size the new heater to your household, and we will walk you through a tankless option if it fits your home and gas line.