Clogged head

[ejessen]

I am having trouble pumping my head.

After pumping for about 5 times the pump handle gets very hard to move up/down.

1. First I took apart the head itself and found no blockage in the bowl or pump itself
2. I then disconnected the sanitary hose that leads from the head to the holding tank. I then carefully snaked and used a wet vac to try to unblock the hose, but to no avail.

Any other ideas on how to fix this?

-- Erik (1987, Hunter 31)

 

[kloudie1]

Make sure the vent is open and clear of bug nests or other stuff..

 

[Peggie Hall HeadMistress]

A manual toilet that gets increasingly hard to pump, or an electric toilet that starts "burping" and spitting up, is a strong indication that the tank vent is blocked. That's always the first thing to check.

All tank vents have two primary functions: to provide an escape for air displaced by incoming contents and a source of air to replace contents as they're pulled out. If air can't get out the vent, it pressurizes the system, creating backpressure....and that's what most likely is causing your toilet to become harder to pump...the pressure escapes a bit between uses, but a few pumps re-pressurizes it.

The two most common locations for a vent blockage are the vent thru-hull and the other end of the vent line--that end of the hose and the vent fitting on the tank. Start by cleaning out the thru-hull...use a screwdriver blade, ice pick or whatever works. If there's a screen in it, knock it out...screens cause more problems than they prevent. If that doesn't solve the problem, you'll need to remove the vent line from the tank (open the deck pumpout fitting cap first to relieve any pressure in the tank). Scrape out the waste that's built up in the fitting and the end of the vent line.

Don't try to pump out or dump the tank until you're sure the vent is clear. If the pump can't pull in air to replace contents as they're pulled out, the pump will pull a vacuum that prevents more than a gallon or two from being pulled out....and particularly strong pumpout can crack or even implode a tank.

Taking the pump apart would have given you an excellent opportunity to lubricate the toilet, which prob'ly needs it if you haven't done it recently...a shame you didn't think to do that. You'll find all kinds of good information on how to lube a toilet (just pouring something in the bowl doesn't do much good) in archives of the plumbing and sanitation forum.

 

[ejessen]

Thanks Peggy - went down to the boat today and tried the following :

1. Detached the vent hose from the hull fitting and confirmed that there was nothing blocking into the first 1-2 feet into the hose
2. I then reattached the hose to the hull fitting, and forced fresh water into vent hose from outside the hull. I was able to force water into the hose for more than 10 sec, unobstructed.

Do you think this is enough to conclude that the vent hose is clear?

What I havn't done yet, is to disconnect the tank end of the vent hose and check for blockage. Hard to get to, but can be done with a fair amount of swearing and nimbleness.

-- Erik

 

[Peggie Hall HeadMistress]

I think you need to do that.
If this doesn't solve your problem, the next step will be to figure out whether it's in the toilet or the plumbing. Easiest way to do that: First, put a pot or pan under the toilet discharge fitting to catch spills... remove the toilet discharge hose...remove the joker valve from the discharge fitting..flush the toilet. (Replace the joker valve while you have the hose off..that should be done annually). If the toilet flushes ok for a dozen pumps, your problem has to be downstream of the toilet.

But my money is still on the tank vent till I'm proven wrong.

 

[Levin]

My best guess would be a calcium build-up in the hose that goes from the head to the holding tank. This is common in most sea water flush heads. It makes it very difficult to pump and eventually can block the whole hose making pumping impossible. You can use muric acid (available at most home improvement stores) to clean out the hose. Just be careful with the stuff. There are many old posts that talk about how to use it properly.

Take care,
-Levin

 

[Rick D]

Erik, given the age of the boat, Levin may well be right regarding build up in the hose. You said you ran it. How far did the snake go? Did it hit an obstruction? What did it look like? I ask because after a guest flushed some TP down our forward head, it clogged. She tried to pump it, but only succeeded compressing the TP into rock and moving it way down the hose. It was too late, even filling with vinegar and letting it sit. It would slowly pass liquid, but that was all. It turned out, I was able to snake it clear, but I found there was a low spot and failing to fresh water flush well before leaving the boat regularly had resulted in a build up at that point. Anyhow, the ending is that it was cleared and it works fine again. I think you may have to get the end of the hose loose from the tank. I have had a clog or two right at that junction over the years in a couple of boats. Good luck!

 

[DianaOfBurlington]

Okay; I'm waiting with bated breath. Any developments on this?
Rick D, any idea (maybe from what your guest said) how much TP proved to be too much?