Carver Owners Forum

Hi all,

I went down to the boat today to find a pretty major leak coming from the toilet on our 325. Any standing water had drained down the shower drain, but the bath mat in there was completely saturated and there was quite a lot of water on the floor in the head.

I had noticed recently that the level in the black water tank seemed to be increasing while the boat was at the dock and the toilet wasn’t being used, but I thought maybe it was just due to the boat rocking back and forth or something.

As far as I can tell, the water pump module on the toilet is broken, or there is some sort of valve in the pump that is stuck open, because water was freely flowing up the flush hose and into the bowl.

The leak that made is way unto the head floor was due to the water coming up the flush hose and backing up into the line from the deodorant reservoir, which eventually overflowed and leaked out onto the floor.

In the process of checking all this out, I also found out our shower sump stopped working (going to post another thread on that)

Here’s a picture of the toilet (Crown model, original from 1996). Unfortunately I don’t have the manual, but I think it’s best I just replace the whole thing anyway.



If you have any suggestions for a simple fix, I’m all ears.

Here is where I need help. In choosing a new toilet, there are two types: one which is designed to be connected to a pressurized fresh water system, and the other which has a water pump to draw water from a raw water intake. When I went into the engine compartment to try to turn off the water, I was expecting just a raw water seacock. The owners manual said that all toilets, regardless of model, were fed by a raw seawater intake. However, when I dug in, that’s not what I found. It seems like the PO plumbed the toilet intake to the fresh water system on the boat, but did it upstream of the water pump, so it is essentially fresh water, but unpressurized. Am I seeing this correctly? Yellow arrows are pointing to the toilet intake hose.



If I’m correct and that is how it is plumbed, then I think I’ll need to use the style of toilet that has a pump and is designed for a raw water intake. It was very obvious that the toilet is not connected to the pressurized water system based on the slow drip of a leak, and because turning the water pump off and draining the water in the lines going to the sinks did not change the flow coming through the toilet flush line at all. I did turn off the red valve upstream of the water pump and toilet intake and that stopped the flow at the toilet.

Thanks so much for any guidance you can provide.

Ok, after doing some further reading, I think we may have a bigger problem here. Apparently you should never connect your toilet intake with your fresh water supply without backflow protection like an atmospheric vacuum breaker, which I do not see here at all. Am I missing something or did the PO do a shoddy and dangerous job here? Yikes!!

Isn’t this something our surveyor should have caught?

I’m thinking I should take this opportunity to connect a proper fresh water toilet to the pressurized water system. That would entail removing the tee before the water pump and then I could tee into the pressurized line after the pump, right?

Can I use standard PEX tubing or is this going to be a different diameter? I think I remember reading about that being an issue. I haven’t done any marine plumbing.

You're definitely on the right path. YES, it is an issue to connect to the potable water system without any kind of backflow prevention device!

With no pressure, I'm surprised you were seeing a lot of water flow. Is the level in the water tank a lot higher than the toilet?

km1125 wrote:Source of the post You're definitely on the right path. YES, it is an issue to connect to the potable water system without any kind of backflow prevention device!

With no pressure, I'm surprised you were seeing a lot of water flow. Is the level in the water tank a lot higher than the toilet?

Yes. In fact, I just put 2 and 2 together - I filled up the fresh water tank right before leaving the boat last time and I’m sure that’s why the toilet leaked when it hadn’t been leaking before. With the toilet intake hose being close to the low point in the boat and the water level being high in the tank, gravity took over. I bet we’d see very little water flow if the fresh water tank was closer to empty.

I answered my other question on the PEX tubing. I bet my water lines from 1996 are 15mm but I’ll confirm tomorrow. In that case I’ll need adapters if I want to use standard 1/2” PEX and fittings. As a novice plumber I think it would make it easy to use SharkBite fittings, but open to suggestions.

I guess I’m glad now that this leak happened so I discovered this issue with the plumbing.

If you’re talking about the grey lines in the pics, they’re more likely to utilize the 1/2” quick connect fittings.

Viper wrote:Source of the post If you’re talking about the grey lines in the pics, they’re more likely to utilize the 1/2” quick connect fittings.

Yes, those are the lines. That would make my life much easier because I’ll need to run a 1/2” nipple to the backflow protection solenoid that will be in the intake line for the new fresh water toilet, so a 1/2” quick connect tee would make it really simple. I’ll check the stamping and take a picture when I’m down there later today. Thanks!

If the level of water in a full fresh water tank is higher than the toilet pump, then you must have a vented loop in the intake line. If this is the way it's always been though, then all owners would have had this problem with a full water tank and I'm thinking that's not the case. Out of curiosity, I would check to ensure that your toilet pump's impeller is still in good shape and that the fins haven't taken a set, that might correct the problem.

They are good toilets that can be completely rebuilt but they are power hogs at just under 40 amps during operation. Having said that, they only take a couple of seconds to evacuate the bowl.

BTW, yours wouldn't be the first toilet I've seen hooked up in that fashion to the fresh water system on a Carver, and the ones I've seen looked factory and always hooked up in the same spot. They may not have been as concerned with siphoning as there's only so much water in a tank versus a raw water hookup.

Got a closer look at the pressurized water lines today. You’re right, Viper. They’re 5/8” OD 1/2” ID so should be compatible with standard PEX and quick connect fittings. That will make plumbing the new toilet much easier.

Is this CPVC? I didn’t see the material type anywhere in the stamping. If so, looks like the best way to cut the CPVC tubing in place would be to use a “C” style tubing cutter?

Pic attached.

Thanks for that and for linking the owners manual, Viper, super helpful. I’ll take a look at the impeller. That’s good to know that it isn’t unique and maybe was actually plumbed that way from the factory, but I’m still leaning toward getting a proper fresh water toilet with backflow protection and connecting it up to the pressurized system, just for peace of mind. Is there a downside to going that route aside from it just being a bigger project?