Options to Convert to Fresh Water Flush

[Skipper]

Head Pumps 101 Why just pouring water into the bowl is NOT a good idea http://c34.org/bbs/index.php/topic,5865.msg40604.html#msg40604.

It's an exactly fantastic idea. If you're concerned about watering the internal bits, one could flush with seawater on occasion.
That's the beauty of "selectable".

For the liveaboard, a different policy and setup may be warranted. However, I know guys who rarely draw seawater into the head. And their heads are fine. Including my Raritan. Periodic maint at rec intervals.
The reduction of seawater, combined with rigid cleaning routine, makes for a sparkling and fresh head. We use it every weekend, and have since installed 5 years ago with zero problems.

 

[Skipper]

That's not how marine heads work.

I don't understand your statement.
It's just pouring fresh water into the bottom of the otherwise empty bowl. The water blocks the discharge hole at the bottom. Are you saying to not do this?

 

[Stu Jackson]

No, skip, I'm saying that the valves on the toilet keep the gases from coming back into the head, not the water at the bottom of the bowl, it is completely unlike a house with P traps.

 

[Skipper]

No, skip, I'm saying that the valves on the toilet keep the gases from coming back into the head, not the water at the bottom of the bowl, it is completely unlike a house with P traps.

Makes sense.
Although inside the head tube from the bowl to the pump can be calcium buildup etc which retains odors. Also joker valves are notorious, especially on cheaper heads. Reg maint and clean outs combat this but I even sometimes get some minor odor with the bowl totally empty, and the water stops it. Common practice on my docks. Even a small odor will eventually fill the head compartment. I'm picky so no odors allowed.

 

[Peggie Hall HeadMistress]

After flushing, if you put just enough fresh water back in the bowl to cover the discharge hole, it will prevent odors coming up from the interior of the discharge hose and holding tank, if there are any.

The joker valve in the toilet discharge will block any odors from the head discharge hose...that is, unless it's been so long since it was replaced that the slit has become open hole. Only one of the reasons why joker valves should be replaced annually. You'll find the other reason in a file in this forum called "joker valve 101."

 

[Mulf]

I built a box out of Starboard and installed it on the wall above and behind the toilet, placed a bladder tank inside, added a fill hose on top and a drain hose to a y valve inserted in the sea water to toilet line. I fill the tank from the shower hose. Thus, I have days of fresh water to flush, can switch easily to sea water (but I never do), and it can be operated just like the manufacturer intended. I don't have but can take pictures if anyone is interested.

 

[Peggie Hall HeadMistress]

Seems to me it would have been a LOT simpler just to tee the head intake line into the head sink drain line. Flush with sea water or close the seacock and fill the sink with clean fresh water to flush with fresh and/or to rinse the sea water out of the system before the boat will sit.
But then you wouldn't have had the fun of building your fresh water flush reservoir...so whatever floats YOUR boat for you is all that really matters.