School me on water heaters.

[Duman]

Well... this is all good info. Last Friday morning, water heater kicked out tons of hot water as usual. Saturday morning, 'hot' water was luke warm.
Gas water heater, pilot light is running, install date 2012. Is there a temp sensor that could have gone out?

[rjr6150]

Well... this is all good info. Last Friday morning, water heater kicked out tons of hot water as usual. Saturday morning, 'hot' water was luke warm.
Gas water heater, pilot light is running, install date 2012. Is there a temp sensor that could have gone out?

Is your main burner kicking in? If yes then could possibly be the dip tube which drops to the bottom of your tank on the cold water inlet side. Typically these are plastic.