air vents

jim P._2

Would you use an automatic air vent or a manual one? Can the automatic air vent go bad and cause water leakage? I have to install an air vent at the highest point of my system (2 nd Floor) to remove the air (gurguling noise). I have a hot water heating system, 4 zones- all series loop, 2 stories + basement, boiler temp set at 180 F, all baseray rads, bladder type expansion tank with a spirovent. Only one of the rads is making this gurguling noise and thats the one I am planning on installing the air vent at the top tapping. I do have a hoffman automatic air vent. Is it a good product or is there something else thats used by the pros on this site? Thanks Jim.