Terry, that noise could be consistent with excess air in your system. Adding an auto air vent at a high point where air is collecting could help. Also you may want to consider our 551 Discal air separator. This product has a coalescing mesh element that will separate the air from the water and remove it. It is a multi-pass device and is more efficient in removing air. The air vent typically does not separate the air from the water it simply removes air that migrates into the vent body.
Terry, that noise could be consistent with excess air in your system. Adding an auto air vent at a high point where air is collecting could help. Also you may want to consider our 551 Discal air separator. This product has a coalescing mesh element that will separate the air from the water and remove it. It is a multi-pass device and is more efficient in removing air. The air vent typically does not separate the air from the water it simply removes air that migrates into the vent body.