Vent for holding tank?

[SeaingDouble]

I noticed last season that although my holding tank had been emptied, it was still difficult to flush. It would take a while for the "contents" to go down and was usually accompanied by a "burp" or 2. <br />Could this be from a clogged or obstructed vent? What else should I check?<br /><br />Thanks

 

[Dunaruna]

Re: Vent for holding tank?

Is this a system with a mercerator or just flush and hold?<br /><br />Aldo

 

[waterone1@aol.com]

Re: Vent for holding tank?

That most definetly sounds like a clogged vent line. If you want to make sure, flush the head (just water is fine) and go to the deck pumpout cap and SLOWLY start to loose it (have a paper towel handy just incase) if you start to hear a hiss of escaping air, retighten. You have a plugged vent line.

 

[rwidman]

Re: Vent for holding tank?

Some boats have a filter in the vent line. This can plug which effectively plugs the vent line. Many of the "experts" recommend doing away with the filter.<br /><br />This is a good book on the subject:<br />

<br /><br />It's available from iBoats.<br /><br /> http://www.iboats.com/mall/index.cgi?prod_id=46422

 

[navigator336]

Re: Vent for holding tank?

If the vent checks out O.K. (it sounds like it is the vent though), the next likely culprit is the joker valve and/or the line immediately adjacent and down stream of it. The downstream line will build up with calcified material just like clogged arteries.

 

[SeaingDouble]

Re: Vent for holding tank?

Thanks for the replies. It looks like I'll be looking into the vent line first.<br />What is a joker valve?

 

[waterone1@aol.com]

Re: Vent for holding tank?

The joker valve gets it's name because it looks like the joker from the old batman series. If you have a manual flush head it is at the outlet of the pump assembly (you cannot see it untill you take the assembly apart). If you have a vacuflush head there are four joker valves (two on each side ) in the electric pump. Joker valves do fail and need to be replaced as needed. If you have a regular electric flush, there are no joker valves.

 

[SeaingDouble]

Re: Vent for holding tank?

All I know is I hit a button and the toilet flushes until I let go of it. It is definitely electric. Is that regular or vacuflush? What do these joker valves do? <br /><br />Thanks for the help!

 

[navigator336]

Re: Vent for holding tank?

Is it a Jabsco head? They have joker valves. It is a one way check valve that prevents "unwanteds" from reentering the bowl. It is also known as a duck bill valve. It is basically a soft rubber material molded into a somewhat duck bill shape with a slit cut in the bottom. The pressure from the mascerator forces it open, while the back pressure (which is minimal) from the discharge hose and tank force it closed.

 

[waterone1@aol.com]

Re: Vent for holding tank?

From your last post, I am guessing that you do not have a vacuflush. It has been two years since I had one of these apart...so if I screw this up, hopefully someone else will correct me.....OK, here we go. A normal electric flush has two sections to the motor, a raw water impellor that will suck sea water from under the boat to fill the "bowl" and a macerator section that will suck the contents of the bowl and pump it down the hose to the holding tank. I could be wrong, but I do not think that a joker valve is used in this setup ??

 

[SeaingDouble]

Re: Vent for holding tank?

Waterone1 - That is how my unit works...I'm sorry to say that this forum sucks for help...if you have anything bigger than a runabout...try Boat Us...you get no answers here...