I have a hot water heating system with a 4 year old oil burner. The oil burner only provides heat; domestic hot water is provided by a separate water heater. When the oil burner was installed I was advised that it had to run all year round or problems would develop. This seems extremely wasteful. Is it really neccessary to run the burner during the non heating months? What problems could develop? If it must run, should the temperature be lowered? Thanks in advance!