Well we have finally faced the dreaded clogging of the head vent . After looking for the end of the vent line , found at the pt stantion I tried to ream the clog from the stantion and the hose , no deal ,so I disconected the hose from the tank end , removed it from the bulkhead and ran it out the pt window , tiebacked it to the shroud and filled the hose with water . The idea was that with a head of water sitting at the clog it may soften it up . The next day I took the feron horn ,placed it up to the hose and blew. Nothing at first but second try out the clog came filled the hose several times and blew , more stuff came out . Hooked the hose up , done. Sure beats taking the hose conpletly off.