I have a headmate toilet in my boat. But I can not pump water up to it. I checked the fitting go threw the bilge area and it was open and not clogged. I disconnected it at the toilet and the fitting in the bilge and tried at both ends running water through it but it seems to be clogged. Is there usually a check valve in the line somewhere? I tried running an auger through it but will stop after about 6'? Any ideas on this? What would clog a fresh water line?