What do you think is going on here?
Last year the overheating safety device shut down my generator. After checking a few things, I removed the hose and determined the thru hull valve was plugged. Got out some wire and tried to open it up, then used my shop vac to blow air down thru the valve. Nothing worked so I re-plumbed to a unused thru hull and carried on. A few weeks later while in the engine room I opened the valve and water flowed freely thru it, so reconnected to it with no problems until last week. Same thing happened again a few days ago. The next day we cruised to another location and I checked the valve. It was once again working fine.
So it gets plugged up, can't free it up, cruise a day or so, and it is cleared out. Very strange. Almost like there is a vacuum created while under way that clears it out? What do you think?