Customer called in needing water heater looked at. Pilot light keeps going out. Upon arrival determined that water heater was built in 2005. Water heater is 21 years old. Checked mV on thermocouple and it measured 14.4mV. It needs to be measure between 20-30mV. Will need to replace pilot light assembly. Gave customer options and customer opted to go with replacing pilot light assembly. Educated customer most water heaters only last 8-12 years and the next thing that could go wrong with water heater is either gas control valve failing or tank itself starts leaking. Went ahead and cleaned inside of water heater and also cleaned burner assembly as well. Installed new pilot light assembly. Checked for gas leaks and no leaks detected. 1 year warranty on pilot light assembly.