Have someone look into installing a microbuble air elimination system on the boiler. This device has the capacity of removing all air from a system. the brand we use is made by Spirotherm and is called Spirovent. They work. The description makes it sound expensive but it is merely a newer way to remove air than the old air scoops. Just make sure you dont have an old style non-bladder expansion tank on the system. This will remove the air from it too.
