Carver Owners Forum

The valve for the crownhead (fresh water) got stuck slightly open sometime in the last week. During that time the fresh water tank emptied into the head and subsequently the waste tank.

Waste tank is definitely full now and more than likely overflowed. What happens when the waste tank over flows? I had maybe though the head would have overflowed and drained into the shower sump but didn't see any evidence of that today.

I've since fixed the issue by disassembling the valve and removing a piece of rubber.

Wow! If the waste tank over-flowed, over-filled, be careful when you open the waste cap when you pump-out. Also, the water, if you have one, could have destroyed your waste tank filter since it would ,could have, emptied into the filter hose. Needs to be checked.

The tank would have simply overflowed through the vent overboard. Unless one was installed by a previous owner, I doubt there's a vent filter. If there is though then yes it's toast if the waste got that high. Curious too though how it overflowed the tank and not the toilet bowl.

Curious too though how it overflowed the tank and not the toilet bowl.

Same here.

Ya, I mean the water goes into the bowl, the bowl only evacuates when you activate the pump/flush, so.......?

I never quite knew of our crown head was working correctly. The DRcurrent behavior is that the bowl drains completely after flushing and that there is no standing water in the bowl when not in use. Any leakage into the bowl slowly drains through the crown head and into the waste tank. Are crown heads supposed to retain water in the bowl when not in use ?

Raw or fresh water goes into the bowl and really should only evacuate when you turn it on to flush it. Sometimes a little water will remain in the bottom and sometimes not. If I have water in my bowls when I leave for the weekend, it will still be there Friday night when I return. Even if standing water were leaking past the discharge pump, chances are somewhere in the system it would have to flow uphill into the tank. Several things would have to be in place including hose routing, tank vs bowl level, etc. for the tank to fill up before the bowl. You also have to consider that even with a full bowl, unless your duckbill valves are shot, that water would have to overcome the pressure it takes to open up a duckbill valve that's in good shape. It might drip past them over time but eventually it will find its level and stop. If water keeps going into the bowl and the bowl is lower than the top of the tank, once the water in the hoses reaches the level of the top of the bowl, it'll flow over the bowl.

I'm thinking there might be something more going on. Do you have an overboard discharge system? I wonder if someone plumbed the toilet incorrectly.

All boats I have owned always retained water in the bowl after flushing. Maybe I should say they continued to flow a bit of water into the bowl after being flushed. Happen to be on the boat now. Here is a picture of the bowl that has not been flushed for several hours. Will look the same after a week or so. I put a piece of toilet paper in it so one can hopefully see a bit better. Not a crown, Vacu Flush. The others I have had over the years were all Jabsco units, either manual or manual converted to electric, all behaved the same.

Seems that might be the way to control odor from pipework, acts like a trap.

In the case of Vacuflush, the water in the bowl helps make the seal to maintain vacuum. If you remove all the water, your pump will cycle periodically when vacuum is lost as air slips past the bowl seal in the absence of water. Even if water weren't part of the design, it's basically a closed system, the ball and seal in the bowl would hold back odor as the position of the ball is normally closed until opened for a flush. As an example, the same toilet bowl design is used in gravity systems as found on most RVs. No vacuum and no water needed in the bowl but has the same ball and bowl seal. It's a direct path to the holding tank but no odor because the ball is closed.

With any other design that utilizes a pump be it manual or electric, as soon as fluid in the bowl gets low enough that the pump starts sucking air, that's it for pumping fluid efficiently, it will pump air easier before it gets whatever water is left at the pump. Even if it gets all the water (downhill to pump) it won't pump it to the tank once it starts sucking air. The hose from the toilet to the tank will always have waste in it and is the number one reason for permeation.