Head filling with Dark Water "Sometimes"

[wabislander]

We have encountered an issue with our Cutwater C28 that periodically after running for the day, the head bowl will be full of dark water from the holding tank. We have already replaced the choker valve (may need to again with dumping some bleach down during pump out). Wondering if anyone else has experienced and if so, their solution. Thanks in advance for any feedback.

 

[snydzy]

Try this:
https://youtu.be/ftNRhtPjqGw

 

[Martin610]

I think that valve may be called the 'joker' valve.

You don't want to use the typical household cleaning products in a marine sanitary system. They are too harsh. So, yes you have to replace the valve.

I use "CP" short for clean potty. Cleans well and doesn't damage anything.

-martin

 

[BB marine]

It sounds like the waste system needs a good cleaning. I would start with the vent. The vent hose and vent fitting is 1/2" The vent can get blocked from toilet paper and waste. If the vent is blocked or partially blocked this will build pressure in the tank. The pressure finds the path of least resistance. If it can't vent out the though hull it will vent out the of the head. The Joker Valve is not a positive closing check valve. It is not designed to hold pressure just stop back flow. If the tank is not venting properly the waste will set in the 1 1/2" waste hose which is about 15' long. This can get nasty because it is not in the tank getting eaten by the good bacteria bugs that live in the tank. The worst thing you could do is pour Bleach in an active waste tank. It will kill the bugs and make things worse.

My suggestion remove the vent hose from the though hull fitting. Use a female hose fitting and attach it to the vent hose. Use a fresh water hose attached to a city water spigot and attach the the female hose fitting you just installed turn on the water. When you hear a flow of water going into your waste tank the vent hose is clean. Before reattaching the hose to the though hull fitting confirm it is clean with out restriction. Reattach the hose.

Flush 2 to three gallons of fresh water pouring into the head and flushing. If you have raw water flush shut the seacock to prevent salt water from getting into the waste hose and tank. The hose should now have clean water in it.

Pump the tank out

Gain access to the waste tank. Early models had the waste tank in the aft section of the cockpit. The removal of the seat and storage pan will can access to the access port that unscrews. When the the port cover is removed you can use a garden hose and start straying water to loosen all the crud in the tank waste and paper. Spray until it is 1/4 full and pump out. Now is the time you are going to kill all the bugs. I pour about 1/4 gallon of bleach into the tank and fill the tank about half way. I Pour a cup of bleach into the head and flush with a a full bowl of fresh water. Let it sit for a few hours. You are killing the good and bad bacteria. After a few hours pour 2 gallons of clean fresh water into the head bowl and flush. Fill the waste tank with clean fresh water. Pump it out. After pumping it out fill again with fresh water to rinse all the bleach out of the tank flush couple more gallons of water into the head bowl. (You want to get all the bleach out of the system)

Your tank should be clean and ready for use. You will not see that nasty water back flushing any more.

I do this at the end of every season. I have never found the need to filter the vent. I have never had any black tank odors in my boat. If the waste tank stinks it is because you have a dirty tank with bad bugs living in it.


Aerobic bacteria (the good guys) requires oxygen to live and function. Keep the tank vent clear.

anaerobic (odor-producing) bacteria. ( bad guys)

Use a Bioactive or biologic treatments that contain live aerobic bacteria, to keep the waste tank clean. This works well if the tank is vented well.

Enzyme treatments accelerate the digestion of organic materials in waste and neutralize odors at the same time. If using enzyme treatments make sure that is the only treatment you use in the tank.

I used Enzyme treatment and also converted my head to fresh water flush. No smells, back ups, no need for the orange filters and the tank stayed clean Transparent, I alway could see what my wast level was.

Is this over Kill ? Maybe! My biggest boat turn off . A boat that smells like waste tank.

 

[wabislander]

Much appreciated for the feedback. Looking forward to my fun holiday project. Will post results, although we won't be back on water to check until February.

 

[Diver]

Keeping the system clean is one thing but black water flowing back into the toilet it a different issue. There are three things that generally cause this.
Joker valve leaking - should prevent backflow of gases and waste back into toilet, but these can leak and do. This valve provides the function of a water trap without the water.
Overfull or nearly full holding tank - waste should drain into tank not back out. If close to full may splash back into line in rough water.
Low points in the waste hose collecting black water. This then slouches back and forth and can make its way through the joker valve. This is common as the hose my sag over time or has insufficient run angle to the holding tank not allowing hose to fully drain. A good indication of this is sometimes sluggish flushing or even clogging of toilet.

In my case the toilet was installed with a long low spot (over two feet long) by the toilet. This was collecting black water which was causing occasional hard flushing, clogs as well as smell. I replace and rerouted the hose to eliminate this and have not had any problem since.