Speaking of "Fresh Water" flushing.... How?

Tim R. · Jan 2, 2013

On our previous boat, a 1985 Ericson 35-5, we had the head intake plumbed to the sink drain. The trick here is to make sure the T is below the WL. That way you do not need a stopper in the sink. We always flushed with salt water but did a rinse with fresh when we left the boat.

Our current boat has a fresh water electric toilet with a solenoid valve. Our fresh water capacity is 175gal with a 12gph watermaker. Our second head at the base of the companionway is a Lavac with salt water intake. We do use the shower head faucet to rinse the Lavac with fresh when it gets used. This gives us the best mixture of luxury, redundancy and simplicity.

RichH · Jan 2, 2013

Sanitary codes developed in the mid 19th century MANDATE that there MUST be an suitable air gap between the water supply and any 'toilet'. The 'air gap' prevents retrograde contamination of bacteria, etc. into the main sanitary water supply ... 'bacteria swimming upstream'.

Valves can leak, check valves can leak, etc. etc. so that retrograde contamination can occur ... and did so back then causing severe cholera and other 'nasty' intestinal diseases/infections. .... and the 'air gap' must not be from the 'rim of the bowl' and the head pump as on a marine toilet as that is or can be in direct contact to 'poo'.

The fill the sink technique, the 'shower wand' technique, the common domestic toilet tank and float valve (w/ two air gaps) are all 'air gaps' that prevent retrograde INFECTION or contamination of a potable water supply.

fox islander · Jan 2, 2013

...another vote for simply using the sink/shower fixture. If I ever run out if fresh water...flip the valve and use sea water. No head smell at all

LuzSD · Jan 2, 2013

We have the seacock closed and only flush via fresh water in the sink. Its easy and clean and sometimes I leave the boat with some CP (Raritan Clean Potty) in the sink drain; it then goes through the head flushing system at the next flush. It's really easy and clean. If we were on a trip, we just open the seacock when we flush, and use salt water until we can go back to fresh. Not a big deal at all. For a while, at first, we used the shower head directly but the drips were a drag and I LIKE running fresh water through the flush/pump system.

I sure miss Peggy.......:cry:

capta · Jan 2, 2013

As full time liveaboards, our heads do not generally stink; too much use in pretty clean water.
I thought the reason for the fresh water toilet flush was to eliminate the build up of the porcelain like substance in the exhaust lines. This stuff causes a lot more head aches (no pun intended) than any odor, to me. Our exhaust line, after all the myriad of hoses and valves the holding tank system requires is about 15 feet long and I have yet to find a way to flush anything through the lines that will remove it. I've tried white vinegar, "On & Off" and muriatic acid (kind of scary stuff to use at any time), but I've found no way to fill the lines completely and keep it in the lines long enough (I worry about the bronze sea cocks) to remove this stuff.
Please, any realistic suggestions would be greatly appreciated.

Nodak7 · Jan 2, 2013

RichH said:
Sanitary codes developed in the mid 19th century MANDATE that there MUST be an suitable air gap between the water supply and any 'toilet'. The 'air gap' prevents retrograde contamination of bacteria, etc. into the main sanitary water supply ... 'bacteria swimming upstream'.

Valves can leak, check valves can leak, etc. etc. so that retrograde contamination can occur ... and did so back then causing severe cholera and other 'nasty' intestinal diseases/infections. .... and the 'air gap' must not be from the 'rim of the bowl' and the head pump as on a marine toilet as that is or can be in direct contact to 'poo'.

The fill the sink technique, the 'shower wand' technique, the common domestic toilet tank and float valve (w/ two air gaps) are all 'air gaps' that prevent retrograde INFECTION or contamination of a potable water supply.

Rich, this posting got me thinking about how our boat is plumbed. We have fresh water to the vaccuflush systems (2) on the boat. All our fresh water comes thru a manifold located in the Galley. There is no check valves in the system. The water pump feeds the manifold and the lines to the head go from the manifold to the toilets along with all the other places. I see no problem with this because there is no way for the water or waste to go "backwards" in the system but I am not certain that it meets your description above. There certainly is a "break" in the system since the water goes into the bowl from the top and goes out the bottom. For the dirty water to back up it would be nearly impossible. Similar to the water in your home toilet backing up into the tank and then into your water system. Your thoughts?

Ron20324 · Jan 2, 2013

This is why there are governmental and private (ABYC for one) health & safety regulation-makers: to protect those without knowledge or the wherwithall to know better and do not listen to those who do. Water trickles down from the top rim and connects to whatever is living in the mess in the bowl. That you "see no problem" is of no particular concern of ours what happens to you, but it is your guests who have some faith that you and your boat are safe to be on and use. WE care for those people.

Besides, some of these "opinions" are going to force Peggy to come charging out like the calvary to the rescue to try to slap some sense into people.

Chris Patterson · Jan 2, 2013

Yeah, I for one would like to hear a little more from Peggy.

Capta, the only thing that I have found to deal with that particular problem is C.L.R. Yes, I too have thrown everything in the hardware store at that stuff, with meager to zero results. But the C.L.R. worked. Now, filling an entire 1 1/2" line, 15 feet long might get a tad costly, I'm not sure how you might work this out. But when I've rehabbed older heads, that stuff would be on everything. I'd soak them for a short while, and the parts would look fabulous.

RichH · Jan 2, 2013

Nodak7 said:
Rich, this posting got me thinking about how our boat is plumbed. We have fresh water to the vaccuflush systems (2) on the boat. All our fresh water comes thru a manifold located in the Galley. There is no check valves in the system. The water pump feeds the manifold and the lines to the head go from the manifold to the toilets along with all the other places. I see no problem with this because there is no way for the water or waste to go "backwards" in the system but I am not certain that it meets your description above. There certainly is a "break" in the system since the water goes into the bowl from the top and goes out the bottom. For the dirty water to back up it would be nearly impossible. Similar to the water in your home toilet backing up into the tank and then into your water system. Your thoughts?

The Dometic VacuFlush valve looks strangely similar to the "Sloan Valve" arrangement ... the small 'valve with a large handle' that you see as a replacement for the usual 'tank' in commercial installations. The 'sloan valve' has an air gap inbuilt and has been NSF certified for many decades. For simplicity and surety, Id check with your VacuFlush for the NSF certification for connection to a potable water delivery system to be 'sure'.