Air in lines when switching to cooling?
Denizens of Reddit, save me! I am entering Year 4 with a Waterfurnace 7 (non-pressurized). During the 10 month heating season in Buffalo, everything works as intended. However, the moment the system switches to cooling mode for the first time, the pipes gurgle, the flow slows, and air enters the system (it's like a waterfall in the basement where the pipes dip down). Switching back to heating mode does not change things; the air remains until it is purged.
This process has been repeatable for all 4 years now, and the only solution has been for Buffalo Geothermal to send a guy out here, purge the line, and increase the pump power just for the summer months. It'd be in everybody's best interest if the problem could be resolved permanently. Has anyone encountered this before or have any thoughts on a possible problem/solution?
Note that opening the cap to check the water level does not indicate a large leak, but at the same time it's difficult to tell, as the water explodes out the top during cooling season if opened. When I check in the middle of heating season though, the water level remains constant over time.