Arrived and found the boiler tripped. Reset and the boiler ran good for 5 seconds then ran rough and shut down. Found the air vent leaking a lot at the top of the boiler. Closed it off and continued to check the system over. Checked oil pump pressure, and the oil flow. Oil pressure is at 140psi. Found the oil had some air in it when bleeding it. Found the oil seeping out of the joints from the filter to the oil pump. Took it apart and redid the pipe dope on them. Also replaced the filter and gasket. Tested the oil flow after and had to air in the line. Started the system and it ran longer but then started to run rough and shut down again. Opened the combustion chamber up and found the entire thing soaking wet. The target wall which is fiberglass was wet. This is what is causing the boiler to run bad and then stop. Due to the air vent leaking all over the boiler it caused the chamber to get soaked. We will need to return tomorrow to replace the air vent and the target wall. Scheduled be