My kitchen sink is not located very far from water heater. We have two separate outlets for hot and cold water. When i open hot water outlet it takes ages to get hot water. The piping is through crawl space. house is 1960 vintage. Boiler has been replaced 5 years back. Is it necessary to insulate hot water pipe in crawl space. My friend says insulating pipe will increase chances of mold in crawl space. Please advice