After 10 years+ having my Hunter 31, I have been having problems getting my tank to empty in recent months. I disconnected the vent hose and pumped water and air into it, clearing it once. That worked for a month or two. Tried that a couple of times recently, and the pump out station just sucks and sucks, I see brown water going through the line, but it won't empty, not even close. Where should I be looking for problems? A vacuum leak somewhere, stopped vent, issues in the tank or pump out drain line?
Tank won't pump out
- Thread starter RogerinOrlando
- Start date
word of caution ...don't try to put compressed air in the tank it will rupture the tank with as little as 5 psi...
...make sure your vent line is clear and free flowing air.....then you may have to take a snake of some kind and clean out your pump out hose mounted to your deck fitting...and you may need to check to see that your pump out hose is not collapsing under vacuum pressure or your vent line as a matter of fact check the collapsing thing first
being 10 years or older you may need to change out the hoses if use trident 101 or 102 they are wire reinforced..yes there are expensive but you will not have this problem again and no permeation of odors/smells and hose will not leak installed correctly
I had this problem and it was the 90 degree elbow vent fitting into the tank. It was packed with crap. I unscrewed it and replaced it with a new one from the hardware store. I had thought that disconnecting the vent hose from the fitting would allow a pump out but it turned out the line was clear and it was the elbow fitting that was clogged.
There is a T-fitting to the manual pump-overboard join which no pipe snake can traverse, meaning that choke point and the entry to the bottom of the tank one (1.5 more feet of hose) don't seem reachable without getting sewage all over the boat. Tried pushing a garden hose down as far as that T, turning it on and clean water and scaling came out. For a tank that's only had dishwater dumped into it for many months, that promises to be quite the mess. Jesus. Anybody else got a suggestion before I deal with that option?
Had a similar problem where a bunch of calcium salt flaking sloughed off the tank walls after a boisterous sail in waves.. The flakes bound up in the Tee and some water would slowly pass. I managed to fill with fresh water and slowly pump out with the manual pump.. Took a while and some patience.. did that a couple of times until I'd convinced myself that the tank was as clean as it was going to get.. then opened the tee and cleaned it out. Still a pretty big mess, but not as bad as I had envisioned. Have a big rag handy to stuff in the hose to stop it while you contain the mess. Have the fresh water hose in there with you. You may have some major scaling in the hoses .. from the head to the tank and from tank to the thru-hull and the lower end of the deck pumpout line and T.. Good Luck with it !
Roger:
I would replace the vent hose and see if that works. When you replacing the hose you will be able to check to see if anything is blocking the fitting in the tank. It sounds like you are probably getting some suction but that hose is probably still partially blocked.
Do you have a manual discharge pump?
I would replace the vent hose and see if that works. When you replacing the hose you will be able to check to see if anything is blocking the fitting in the tank. It sounds like you are probably getting some suction but that hose is probably still partially blocked.
Do you have a manual discharge pump?
Had this problem on another boat that had not emptied the holding talk in a LONG time. The stool compacted in the bottom and I had to physically break the stuff up and remove it. This wan not a fun job but no problem afterwards.
I blame mud daubers. Those critters love to take up roost in my vent line and can completely plug it up. I changed my vent to a 1 inch line with an open marelon through hull that I can easily spray a hose into to clear the line. The vent line is almost horizontal but slopes from the hull to tank ever so slightly so that anything in it runs into the tank. The safe way to do this and prevent over pressurizing the tank is to have it hooked to your pump out station, start pumping out, and the blast the hose into the vent. The suction will pull the water through (and whatever may be blocking it.)
DO NOT JUST OPEN THE DECK FITTING AND BLAST WATER INTO THE VENT. I say that in all caps, because my dock neighbor discovered the brown version of old faithful when he tried to clear a blocked vent.
Otherwise, have you ever overfilled your holding tank? If so, then you can easily get a sewage buildup in the vent line, that again a little TLC with the hose can help take care of.
DO NOT JUST OPEN THE DECK FITTING AND BLAST WATER INTO THE VENT. I say that in all caps, because my dock neighbor discovered the brown version of old faithful when he tried to clear a blocked vent.
Otherwise, have you ever overfilled your holding tank? If so, then you can easily get a sewage buildup in the vent line, that again a little TLC with the hose can help take care of.
One of my crew used 4 or 5 square medicinal pads. Apparently by the time I pumped out they had sunk and clogged the tank's output fitting. Reversed flushed the pumpout hose broke the pads free and then they pumped out with the rest of the stuff.
10years ?
If it truly has been 10 plus years it may be time to replace all the hoses anyway and if they are built up with scale definitely time to replace. If you think it is a vent issue just remove the vent at the tank and try a pump out , make sure fitting is clear when you do. Also not sure how the tank is plumbed but if it is top drain thru a pick up tube it could be a broken or cracked tube. May be time to do some replacement maintenance. Just no good way to do this just do it. Good Luck !