When arrived, the thermostat was at temperature. Checked the system and found the that there was a lot of air in the system which can cause the water from circulating through the pipes. Purged both zones. Performed a heating pm on an oil boiler. Brushed and vacuumed. Replaced the oil filter, nozzle and strainer. Started and checked the safeties. Performed a combustion test. System is operating properly. While performing the maintenance, noticed some issues that need to be corrected. - the sharkbite valve for the upstairs zone leaks when it starts to get cold - the automatic water feed does not shut off. The valve was turned off when arrived. - the 7” flue going into the chimney has a hole and needs to be replaced - the water line coming out of the domestic water coil is leaking - the oil line is in the concrete. Recommend replacing from the tank to the burner - there is no mixing valve at the domestic water coil.