We opened up the access to the top of our offending holding tank. I spent a half hour taping everything up with plastic just in case there might be some leakage. Then jack unclamped the hose and tried to pull it off the barb. And tried. And tried. Then I tried. And tried. We could twist It and turn it but we couldn’t get it off even one ridge of the fitting. After about an hour we gave up, reclamped it and went back below to snake the hose from the other end. Yep, it’s still clogged. Ugh.
Heat the hose with a heat gun or hair dryer and it will soften and come off.
the plug is most likely in the fitting at the top of the tank, or in the first section of hose. If it’s not too difficult, remove the entire hose and soak it in water to loosen the plug – or replace the entire hose – or replace the upper section of hose – I know, it means another trip to West Marine!
you may not be able to use a heat gun or hair dryer at anchor – could try putting a wash cloth on boiling water then wrap it around the hose to soften it. Or if there is enough slack in the hose, cut the end off the fitting and reconnect the hose.
If it’s any comfort – of course there’s no comfort in working on the head and holding tank – the plug is probably toilet paper that has turned to paper mache (sp?) – you probably know never to use Charmin in a marine head – it contains plasticizers that can cause it to turn to a hard mass and plug the passages or collect on the joker valve – you don’t have the buy the expensive TP at West marine, but look for TP in the supermarket that dissolves readily and is safe for septic systems.
More than you ever wanted to know, I’m sure