losing freshwater on the road

[beengood]

I have a 2019 27RLTS I filled the freshwater tank and traveled about 150 miles and had water sloshing out the overflow the whole trip. Got to the campsite and almost 1/2 of my freshwater was gone. LaMesa RV told me there was nothing they could do about it, called it a factory defect? Never had this with any other 5th wheels we have owned. Anybody have a fix for this? checking before i drop the coroplast.

[Rossi6998]

I installed a shut-off valve at the end of the overflow tube. I ordered the "WATTS 0959098 P-650 Stop Valve" on Amazon. Just don't forget to open the valve when you stop to camp.

May also want to look at the link below:

https://www.roadworkplay.com/stop-th...ater-overflow/

Good luck!

[Lakejumper]

I'm not familiar with your RV but siphoning is usually caused from the tank not venting air when it's filled. If you have a valve that allows you to turn it, when hooked up to city water, to fill your tank, then there may also be a separate filler inlet to use a hose to gravity fill directly into the tank. I have two different ways to fill the tank and the gravity fill has to be open to vent the tank when using the valve knob switched to "Fill Water Tank". Hope this makes sense. If you check the manual, it will tell you if you have the second inlet. If you don't have it, then the vent hose needs to be adjusted or you can put the shut-off valve on the overflow pipe. Make sure to open it when filling or your water tank will expand and can be damaged. My Cardinal fifth wheel didn't vent properly and the tank would "balloon" when filled!

[Dennis L]

An easier solution is to put a pin hole in the overflow tube near the tank to break the vacuum and still allow overflow and prevent siphoning.

[murphy55378]

We had a Motorhome that did that. I found that after filling the tank I would open the tank drain and drain out a couple of gallons and that broke the vacuum.

[beengood]

Not really siphoning just sloshes out during starts and stops. Like there is no loop in the overflow piping.

[AFChap]

It is a common if the fresh tank is completely full. A vacuum apparently forms. In the rare occasions I need to travel with full water, and I get mine completely full, I pull the fresh dump valve for apx 30 seconds & no problem then.

[cthiggy]

Similar problem in that at least half of our Fresh water tank will slosh overboard through the gravity fill opening while driving. The closed/locked door does not seal the opening for the 1 1/2 inch tube as designed. Anybody have a solution??