I installed a new water heater but can't get hot water just a little warm water. What could be my problem? I've been installing water heaters for over 25years and never came across this problem.please help .

With no hot water being used and the water heater up to temperature, feel the hot water out pipe. Is it hot? If so, I would think you have a defective dip tube.

If you have been installing water heaters for 25 years, surly you know not to solder close to the cold water input fitting.