Toilet Always Backflooding

[marob]

We have a 2021 Cutwater 28 bought new and it always has had an issue with the toilet bowel filling up. It appears our dealer replaced the toilet but the problem still persisted. The next year they installed which I assume is a Joker valve (was not installed at the factory) and we still have the problem. Our dealer trailered the boat to the marina for us to pickup and due to the bowel being over have full we had a very stinky mess in the V berth and still dealing with a lingering smell. Wondering if anyone else is having this issue and what can we do to fix it. Thanks in advance.

Rob Miller

 

[KlaassyC]

We had that with our C28 when we first purchased it used, but a new joker valve solved it. I’d confirm that it is actually in good condition first.


Sent from my iPhone using Tapatalk

 

[Cutwater28GG]

yep its the joker valve...

 

[glider4]

Don’t want to hijack this thread but dealing with a related issue on my 2017 C-28. The drains and vent locations shown in the Owners manual for the port side of the boat are not even close to their actual locations on my boat. The waste pumpout is where shown on the manual. Where the heck is the waste vent?
Getting some odors in the cabin and outside (but not in the head!) after flushing and would like to install a carbon filter in the vent line if I can find it and if it is accessible.

 

[BB marine]

Rob,

The waste tank must be close to full?? The Joker Valve will only hold back the waste at 0 or very low pressure. As the tank fills the waste level is above the toilets base where the joker valve is. The rubber check valve (Joker Valve) will hold back waste again at a low pressure. The first thing I would check is the VENT HOSE and VENT at the hull. If The hull vent ,vent hose or fitting at the tank is clogged and not venting. The tank will build pressure and over come the Joker Valve. How do I know this ??? Because my 2016 Cutwater had a inexperienced technician install all my plumbing including the waste tank hose and vent hose. The vent hose was not run properly having a low run to high run to low run. This allowed "Crap" that vented into the line to settle in the low spot. This created blockage and pressure which made flushing difficult after about a half tank of waste. I noticed when I released the deck cap (Waste cap) for a pump out that I had pressure build up when the cap was removed. I then removed the vent house and made up a fitting that I could back flush the hose with water pressure blowing the water back to the tank via the vent hose. I then confirmed the hull vent was clear. This eliminated the tank fro building pressure and also helped the dock side pump out to pull waste better from the tank and head back up.

The next project was to change the hose routing from the head to the tank. The hose run from the head went in a sharp incline then down, then a sharp up again. The photo below shows the waste tank run after I repaired it.
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The photo shows a waste hose installation I did at the head. I cut the hole larger and made a vinyl panel for the hoses to run though the fiberglass head liner. This made changing the Joker valve easier and reduced the angle that the head waste hose ran out and up.
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On the C28 the waste tank is closer to the head. My C26 the tank was located where the generator is on your boat.
This photo shows the head to waste tank hose gradually running up to the waste tank top for discharge into the tank. Before it was a straight run up. The change in the hose routing reduced the amount of "Crap that stayed in the hose reducing the amount of "Crap" back up and we had no waste tank odors in the boat. On another subject this photo also shows the proper way to plumb the auto pilot pump.

gallery2.php?g2_itemId=67962&g2_imageViewsIndex=1

The first thing I would check is the vent. Then hose routing.

 

[Gypsy]

Glider4,
I had the same problem on my C28. I added a charcoal filter and haven't had a problem since.
1) Remove the microwave.
2) The vent line is right there. Cut the line in half and reroute it under the microwave floor, into the pot and pan storage cabinet. No cutting involved.
3) Install a tubular carbon filter. Several are available on Amazon. They are about 16 inches long and 2.5 " in diameter. They come with hose adapter fittings to tie in to your vent line.
4) Mount the filter to the top of the pot and pan cabinet so that it is out of the way. It snaps out of its holder when you need to replace the filter.
Easy Peasy

 

[glider4]

Bill,
Thanks for the info. Just to be sure our boats are configured the same, your microwave is in the v-berth right above the Keurig right?

 

[BB marine]

I’m not sure how installing a charcoal filter for the vent line will cure the bowl from filling up. If that fixes the bowl over flow then an easy repair. My thoughts of the charcoal filter was to filter the air that vents from the tank so it doesn’t stink when the head is flushed.

 

[piglet 2013]

I agree with previous poster check the vent line for a low spot that actually creates a P trap that will not allow the tank to vent causing pressure in the tank. I believe the tank on the later models with the next gen generator located in the rear of the boat has the waste tank located under the hatch below where the built in cooler is and the vent runs up under the stove.

 

[Gypsy]

Bill,
Thanks for the info. Just to be sure our boats are configured the same, your microwave is in the v-berth right above the Keurig right?

No. my microwave is in the cabin. The black water tank is located underneath below the floor. The vent line was behind the microwave. The addition of the charcoal filter was to reduce the smell when the toilet was flushed.

 

[glider4]

Our odor problem seems to solved. Apparently it was a plugged up vent line. Will be doing a number of pump out, add 10 gallons of fresh water and pump out again cycles.

 

[SJI Sailor]

Maybe it will help someone to mention two tips about the holding tank vent.

First, it is good to monitor the vent during pump out. When pumping out, put a hand (and I wear latex gloves for pump out) over the vent hole. It should have noticeable suction. If that is low or absent, it is plugged.

Second, a rubber "fireman's nozzle" spray adapter can fit securely over it and direct a water stream into it to help clean/clear it on occasion. (Like: https://a.co/d/6AIFFdY) I like to do that occasionally at the dock and run for a while when I know I will do pump out soon to help clear residual water.

 

[marob]

Just want to say thank you for all the replies and as usual Brian your experience is a major help. I will check the vent line today. One thing Brian the tank only has about 4 inches of fluid in it. Again thanks all for your suggestions. Have a great boating season.