I have a Keystone Cougar 21RBS equipped with a Dometic 310 toilet. Everytime I travel with it, water sloshes from the toilet unto the floor and into the heater vent. I have been careful to ensure that the pump is off and that all water is gone from the bottom of the toilet prior to departure. Despite this, water still sloshes to the floor. The only way I can avoid this is to place an old rag or towel into the toilet before departure. When I arrive at my destination the towel is saturated. Both Dometic and Keystone say they have never heard of this happening despite Dometic's acknowledgment that water will remain in the "rib flush" portion of the toilet after flushing. Has anyone else encountered this problem?

I've never emptied the bowl before towing. Never thought about that but I've never had any water slosh out of the toilet.

Sounds to me like the "air gap" at the TOP of the toilet may be holding fresh water after you flush. It is supposed to drain out after the water is turned off at the end of the flush.In some cases you can take the top of the toilet off and you will see where the water fill valve squirts water across a open space into a channel, this is the air gap. The channel then goes around the top of the toilet bowl and spills out into the bowl.You may have a miss shaped part that is holding water after the flush and when traveling it splashes out of the top and onto your floor.

Your fill valve is leaking. It needs to be repaired.

After flushing toilet the vacuum breaker should drain into bowl (water in bowl is a vapor barrier). Should only be a few ounces.It sounds like the toilet rim where the water flows into bowl is retaining excess water.Are all the holes in rim free & clear?

If it is under warranty, have it replaced. It certainly is defective.

Dometic toilet sloshes water unto floor | Good Sam Community

rexford
Explorer
Sep 17, 2013
I have the same problem. Before I travel I flush it with the water pump off. May still get 1/4 inch
water in it but not enough to slosh out. I am sure most of us at minimum have a wet toilet seat
after hitting a pothole.
Bigburd
Explorer
Sep 16, 2013
Had a Keystone TT with the bath in the back. Toilet set in the center. Always traveled with fresh water in the front mounted tank. No problem. Decided to tow without a lot of fresh water as some on here recomend due to weight issues. Toilet water sloshed out onto the floor and into the heater duct. Only thing I could think was that the fresh water acted as a damper for the uneven road sections. Lack of the damper causing porposing enough to throw the water out. Filled up the fresh water tank and it never happened again.

Just a thought. Worked for me.
dodge_guy
Explorer II
Sep 16, 2013
Where is the toilet located. If you drain the water out of the bowl do you still get water on the floor?
opnspaces
Navigator II
Sep 16, 2013
Here's a test I would do on my way to the dealer. Turn off the water pump and drain the bowl and use no towel. Then drive a block or two and turn left and right. Now stop and see if there is water in the bowl. If so flush it down then drive on to the dealer. if no more water then there is something holding water in the top of the toilet. Ultimately it probably makes no difference as it's under warranty. But I like to try to figure out what's wrong before I get to the shop so I have an idea if they're trying to feed ma a line.

Curiosity question. Do you open a sink faucet to drain the pressure out of the lines after you turn off the water pump?
garyindaupeh
Explorer
Sep 15, 2013
I have an appointment on Weds. to have it looked at by the selling dealer. It is still under warranty so I think it should be replaced. Neither Dometic or Keystone have ever heard of this happening so it must be a defective unit. They will also be looking at numerous other issues. This trailer must have been built on a Friday afternoon near quitting time. It is really a poorly made unit!

Gary S.
BillB800si
Explorer
Sep 15, 2013
Ex-Tech wrote:
rockhillmanor wrote:
:B

Sorry but no. If the seal holds back water, it will also seal out gasses. No water needed.

=============================

Gases will seep past a gasket much easier than water. Water molecules are larger than gases.
Water in the bottom of the toilet bowl not only insures a gas tight fit it also helps to keep the seal from drying out.

We often drive down the road with our toilet bowl half full of water and it never spills on the floor.
You definitely have a valve problem in the toilet. Have it looked at.
Happy trails,
allen8106
Explorer
Sep 15, 2013
mileshuff wrote:
I've never emptied the bowl before towing. Never thought about that but I've never had any water slosh out of the toilet.

Ditto, never an issue.

I would expect a leaky valve causing the bowl to fill from left over pr4essure in the system then slosh out once it get to a certain height and you hit a bump.
Ex-Tech
Explorer
Sep 14, 2013
rockhillmanor wrote:
After you figure out what is broke and fix it......do NOT drain the water out of the bowl. There is NO pea trap in an RV toilet. You should always leave water in the bowl as a barrier to the holding tank or the next thing you will be posting about is the sewer smell in your RV! :B

Sorry but no. If the seal holds back water, it will also seal out gasses. No water needed.
rockhillmanor
Explorer
Sep 14, 2013
After you figure out what is broke and fix it......do NOT drain the water out of the bowl. There is NO pea trap in an RV toilet. You should always leave water in the bowl as a barrier to the holding tank or the next thing you will be posting about is the sewer smell in your RV! :B
Bears_Den
Explorer
Sep 14, 2013
I'd definitely have it looked at.