I have a 21yr old State/Courier Gas fired water heater (old but looking/working great.)
While doing annual maintenance (checking TPR & draining), I noticed that the cold water supply pipe is actually very warm to the touch, almost hot. Following the water supply line back toward the source, it gradually cools down to a point about 6’ out, where it is then cold to the touch.
It’s apparent that either the hot water is backing up into the cold water supply, or just by conduction the WH is warming the supply pipe.
QUESTION: Is this an issue to be concerned about? If so what are some of the possible repairs/concerns?