Fresh water flush on a Jabsco electric loo conversion

[superheat6k]

I would like to connect my pressurised water system to the loo flush. I was considering using a solenoid connected to the flush switch, but I am concerned the 1.5 bar pressure might be a bit high, plus the switch operates for fill and empty, with a vent valve pintle preventing water being drawn in during 'empty'

Has anyone already hooked freshwater to one if these, if so how did you do it ?

 

[theoldsalt]

I cannot help with advise based on experience but I (possibly like many others) am interested to know why flush with fresh water and not from what the boat floats in.

 

[HermanD]

Flushing with fresh water has 2 advantages.
1e less scaling building up in the system.
2e No more smell from the intake water.

Disadvantage you need a larger watertank.

If you do this, be sure there is no backflow possible from the
toilet tot the freshwater tank.
Otherwise you can pollut the freshwatertank and get possible ill
if you drink this water.

 

[Loggo]

Must agree regarding the smell from river water. If left idle for a week the toilet took a few flushes to remove the smell but was fine after. Seemed a small price to pay for limitless flushing water.
Strangely when we were on the Trent the smell was much worse than the Severn.
When we had the toilet installed a few years ago the marina asked us if we wanted river or fresh water flushing and left me feeling that one or the other was no big deal.

 

[David2452]

I would like to connect my pressurised water system to the loo flush. I was considering using a solenoid connected to the flush switch, but I am concerned the 1.5 bar pressure might be a bit high, plus the switch operates for fill and empty, with a vent valve pintle preventing water being drawn in during 'empty'

Has anyone already hooked freshwater to one if these, if so how did you do it ?

If you have space, and can be arsed you could fit a small tank with a ball valve supplied from your potable water, this would both overcome the pressure issue and provide an "air break" to prevent bacterial migration into the potable water, exactly like at home. I have done this on larger craft abait with somewhat more sophistocated heads.

 

[maby]

As Herman says, it's the sea water that makes the first couple of flushes stink! I've never heard of anyone actually plumbing the toilet pump directly to the boat's fresh water system and I would be a bit concerned about the possibility of bacterial contamination of your drinking water supply - unlike the house toilet with a cistern and ball valve to isolate the loo from the water supply, there isn't actually that much inbetween raw sewage and the water supply to the flush.

The solution that I have seen several times is to fit a two way valve between the water inlet pipe to the toilet and the outlet of the sink in the heads. In normal use, you use a sea water flush but when you are going to leave the boat unused for any significant time, you close the skin fitting on the sink outlet, fill the sink and switch the flush supply to the tee-piece in the sink outlet pipe before flushing. That way, you clean out the supply pipe to the toilet and remove the food supply to those nasty bugs that will build up the nasty smell ready for the next time you use the boat.

Just noticed that David beat me to it!

 

[superheat6k]

Fresh water flush is very common on mobos now. It's the smell issue, plus the flow I would like to improve. I have overhauled both toilet pumps, but neither flushes with very much gusto. I do find a good blast from the shower helps.

I would expect to fit a double nrvv to prevent any chance of backward contamination. I wonder if I could find a pressure reducing valve that would simply take the feed pressure down to just above atmospheric may work. The reducer would also prevent any chance of back flow, and even a slight positive feed pressure to the flash pump would improve the flow.