Originally Posted by CallMeVilla
As standard practice, I write the date of installation on the heater using Sharpie. This eliminates guess work. BTW, if both lines feel equally warm then the dip tube is shot and the heater needs replacing.
If no water has been used for a long time both pipes will be equally warm, with or with out the dip tube being in good shape. So just warm pipes will not be a good rule on it's own, there would have to be a time line difference for the cold water pipe to warm up.
When the dip tube is gone and the house has anti-scauld shower, the homeowner will complain about cooler shower and or has turned up the heat or has adjusted the shower.
All I am saying is watch out for sales gimmicks.