Mystery tank

[MisterMR]

So, I finally took possession of our brand-new 2024 R6! I'll post some glamour shots soon, but in the meantime I am trying to work on flushing the winterization fluid out the water tanks (we have the electric head, sink, and transom shower) while the rain keeps us off the water for the next week or so. In doing so, I came across a mystery box that neither me nor my salesman can figure out. He is running this one up the chain, but I figured I'd let the members here give it a shot.

Waste water and mystery tank.jpg

As the photo shows, the box is beside and attached to the waste tank (black hose). There is also a larger diameter white hose running into the head compartment. The box is NOT watertight. If you look closely, you can see that the top is held on by plastic tabs. In fact, I tried running the sink faucet and the sink seemed to drain into this box, causing it to overflow into the bilge.

Anyone know what purpose this box serves?

For bonus points, can anyone tell me what the tube connected to the hole marked "83" is going to. It looks like it is connected to the raw water inlet/strainer, but this makes no sense to me.

[billk2632]

So that looks like a sump - basically a box with a bigle pump and float inside it. Grey water from sinks/showers drains into the box and is then pumped overboard. Larger boats with sinks, showers are usually setup this way vs a bunch of through hulls to drain directory overboard or just draining into the bilge. Surprised an R6 has this as there is usually just a sink in the head that drains directly overboard. I may be wrong, but based on what I see and that you see sink water draining into it, that's what I am guessing it is.

[jwill323]

yes, definitely a shower sump. If it's standard plumbing it will pump overboard. If it's plumbed for a gray water system it may be plumbed to the holding tank for the head (careful on this because it can fill your black water tank up quickly depending on what drains are hooked to it). Looks to me like you have the gray water plumbing. The pump in there should run regardless of the power setting and it looks pretty full so you may want to check your float switch or the breaker probably labeled sump. Flip your breaker on and see where it drains to, no need to flush it just use the sinks and it will pump out (somewhere!)

"83" is probably a vent, would likely go to a filter cartridge then probably a through hull vent

[MisterMR]

I get the idea of it possibly being a sump, but it doesn't make any sense to me as the only connections seem to be A) the sink, and B) the waste tank.
It's weird and I can't wait to hear back from Cobalt on this one.

I've also questioned them on the lack of a gauge for the fresh water tank level (gauge in the head only measures waste tank level). I originally got back a "we recently changed the R6 layout and the fresh water is now underneath the passenger seat so you can now visually see the level of water in the tank." They may be making this change, but my R6 still has the fresh water tank behind a panel at the front of the engine compartment where you can't visually check it.

Overall pleased with what I have but a few questions that need to be answered.

Oh, and I need to flush out the winterization fluid from the fresh water system. I don't have a goal of flushing the waste system.

[jwill323]

The gray water plumbing is overkill/unnecessary on this boat but likely due to environmental reasons it seems to be the new standard. it would be a much simpler solution to have it just drain overboard but this way everything put down the sink goes into the sump which pumps it into the holding tank. On a larger boat this makes sense because in a shower the floor drain is below the water line and a through hull would not drain so it dumps into the sump and can be pumped up and out. but on your boat or mine (which also has this gray water plumbing) its just an unnecessary complication of what could/should be a simple system.

[MisterMR]

The "mystery tank" has been confirmed as a sump for the sink. The R6 has been at the dealer for the last two weeks while they work with Cobalt to get the problem of it not pumping into the wastewater tank worked out. Apparently some things got wired incorrectly during manufacture, including the freshwater pressure pump (for the sink and the transom shower).

Meanwhile, I'm still working with the dealer to figure out how the level of the freshwater tank can be measured. Per the Maintenance section of the owner's manual:
"Before Each Use... Check fluid levels of freshwater tank..."

Hard to do with no way to visually check, no physical gauge, and no apparent connection to the NMEA system.

[jwill323]

Here is a NMEA tank sender you could use.

https://defender.com/en_us/maretron-nme ... uQQAvD_BwE

[MisterMR]

I know that there are sensors that can be installed. What amazes me is that a freshwater gauge or some NMEA connection was not included in the price of the sink console + transom shower + freshwater system. Cobalt's initial response was along the lines of "Yeah, we used to include that but don't any longer."

I'm not happy that my first month of ownership has been spent dealing with these issues. Just setting the stage for typical boat ownership, huh? LOL