With a house toilet, wouldn't the water down in the bowl, from movements, actually drain into the tank allowing smell to come up? Just curious... I got a nice extra house toilet.... Just bought a new Dometic 320 for $250...now wondering what would be better..
I'm gonna head this off with that I'm NOT a plumber so I don't know the official terms, but I know how this all works, and this is what I'm going to do.
Terms I don't know the official names to but understand intimately how they work.
"Stop" - The cap at the bottom that the chain pulls upwards and seals the water into the upper chamber.
"Float device" - The device where the water line screws into and fills the upper chamber with a float that stops the water fill.
"Upper Drain Pipe" - The backup pipe that is a certain height to drain water down into the bowl in the event the Float device fails and water were to keep filling up the bowl causing a catastrophy.
Upper Chamber Preparation:
Seal the top lid with a rubber liner, and install 2 clamps on both sides of the top lid to securely mount the lid to the upper chamber to prevent water from leaving the chamber and onto your floor.
The problem: Water drainage to the bottom chamber bowl in a bus causes two problems that must be addressed.
The water will splash back and forth,
a lot. We solve the water leak problem with the rubber seal mentioned above, but this is still a problem for the float and the Upper Drain Pipe.
Answer:
1.) The simple fix is Build an accessible shut off valve. You could Cover the emergency Upper Drain Pipe.
Seal it off. It's not needed except when the float fails and incoming water continues. If you do seal it off it will not add water to the lower chamber even with splashing because you cut the water off with the shut-off valve that is easily accessible. This requires some patience as you will need to turn the valve on to fill the bowl up and count to 30, then turn it off again. Or with this method you could leave the upper chamber empty and turn it on when you need it but the lower bowl will be empty and more cleanup will be required so best to have the water in already.
2.) More complex but better solution. Get a PD Meter which can shut off water flowing after a measured amount passes through. Say 2.5 gallons for an upper chamber. Set the meter to this. It's installed in-line, when 2.5 gallons passes through, it shuts off your water to the upper bowl. Do your business, flush, and Press a button and 2.5 more gallons can pass through. You remove the float entirely, just rig a fitting to the lower fill port where the float would normally be installed and have the PD Meter push the 2.5 gallons of water into it. No float required.
In either case seal off the upper drain pipe because it will just leak water into the lower bowl prematurely wasting water.
And
Problem 2:
Potential for the stop to open causing an unintentional flush.
Answer:
This is not really a problem as one would suspect. The stop won't be affected unless the air in the chamber hits the stop which is unlikely as the upper chamber is often filled 70% water/ 30% air. It shouldn't splash enough back and forth to cause the stop to lift and cause a premature flush. The stop would have to be exposed to air and it won't splash that low to open the stop. So not really a problem, just heading this off in case someone says "Well what about the stop?!"
Lower Chamber Preparation:
Add a seal under the lid that sticks to the lid but seals with the lip of the lower bowl. You'll need two sets of seals, one for upper lid, one for lower seat lid, or you could permanently set it so the inner lid never opens, use a sealant, and only use a rubber seal for the upper lid. Use a similar clamp used on the top lid for the Upper Chamber, but at the very front of the lid that clamps down to the lower bowl tightly. That's it.
