I have a state select gas water heater. My house is 2 1/2 years old. The pilot has gone out and has been lite twice. What could be the problem, and how long is the warranty usually on a hot water heater?

Tank 5 to 12 years.

Controls, considerably less and likely no more than a year.

Clean the thermocouple with fine sandpaper. The copper protrusion that the pilot heats. Oxidation reduces the thermal conductivity of the sensor. It can also be replaced.