I am trying to find out for my friend. He has an oil fired system with an indirect Hot water retaining tank. His oil company put it at 180 - HI and 150 - LOW and he feels that was incorrectly too high. Since the last time his burner people were in, he had twins. Should the settings be lowered for the water so as to prevent potential scaulding?

150 to 180 is fine for the heating water. 125 should be about the most to the water heater

The boiler should be cold start with an indirect and the high limit on the boiler should be 180. Maintaining temp on the boiler is a huge waste of fuel.