Flush head with tank water

[Erbardy]

I have asked around and have come up with this plan for my replumming project. Please make any comments or critisims you may have. But please keep it friendly. I am genuily asking for thoughts.

Hi everyone. I have a 1986 catalina 30 that only has the one 17/18ish gallon fresh water tank located under the starboard setee. I have just acquired the 25 gallon water tank that will be installed under the v-berth. I am in west basin of lake erie and spend time at marinas with no more than one or two nights at anchor at a time. I would love to not use marina water to flush my toilet. I am also aware that catalina 30s are plummbed in such a way that you can close the head sink thru hull ball valve to use water in the head sink to flush the toilet. It works but i would rather not continue to open and close the ball valve more than I have to.

As a solution, in my replumming project, i am thinking of installing a "T" from the 25 gallon v-berth tank (after the on/off flow ball valve) with a check valve for both directions. One direction will go to merge with the water line coming from the setee water tank (on the negative pressure side of the pump). The other side of the "T" will go to the head for flushing the toilet (again with a check valve). We do not use water for drinking. i am also going to install a check valve coming from the setee tank.

Thoughts?

 

[Apex]

unless the head is designed specifically for connecting to the water tank: NO. @Peggie Hall HeadMistress will chime in with all of the reasons against, even if you are not using that water for drinking.

Additionally, you are in fresh water...use the lake water freely for pulling in flush water.

 

[Peggie Hall HeadMistress]

Apex is correct...ONLY toilets designed to use PRESSURIZED fresh water should ever be connected to the boat's fresh water plumbing. Rerouting the head intake line to tee into the head sink drain line, is the only safe way to use water from the boat's fresh water supply. Even though you're in fresh water, I appreciate the fact that there are coves that that can be skanky 'cuz they don't have creek water flowing through through them to keep them clean. If you aren't a fan of filling the sink for every flush--and besides, 25 gallons doesn't give you enough water to spare any for toilet flushing--there is a compromise: flush with lake water and use just sink water only to rinse the raw water out of the entire system--intake line, pump, channel in the rim of the bowl--last thing before the boat will sit.

I'll be glad to walk you through plumbing your toilet to do it this way.

--Peggie

 

[Don S/V ILLusion]

Or simply use the new tank dedicated for flush water with no interconnection to the other side. It’s likely equal or close to the capacity of your holding tank anyway so the latter becomes the limiting factor in use.

 

[CurtisC]

Concur with Apex, but make sure your system has a vented loop between the toilet flush pump and the bowl. My '84 Cat 30 MK I came to me with a Jabsco Manual toilet without the vented loop, which I assume was the factory install. Fortunately the top of the toilet bowl sits just above the waterline, because without the loop, lake water can leak thru the pump into the bowl and then to your holding tank (which are all below the W/L) if the sink thru hull is left open for an extended period. When the tank gets full, it backs up seeking equilibrium with water outside the hull. In my case it took overnight, again, fortunately the top of the bowl is set about an inch above my waterline. Technically a more accessible shut off valve could be put in the flush water system plumbing before the bowl, but you'd have to open then remember to close it every use otherwise you could wake up to an unpleasant high tide to your toilet.