Can't fill fresh tank over 1/3

[bigmurph]

I have a 2016 Flagstaff Super Lite 29FBSS. I tried to fill the fresh tank a couple weeks ago and it didn't take much water before it started coming out the fill tube. I shoved the hose in a little further so that it will kind of make a seal I guess. This allowed me to fill the tank. During this the vent/overflow started working and I could hear air coming through it. Today I tried to fill it and the water got to 1/3 and started to overflow out the fill tube. Never could get it filled. I got home and tried to blow through the vent hose. I was able to blow through it. If I blow through the fill tube you can fill the air try to push back at you. If I blow real hard I will get some air out of the vent but I still have back pressure in the fill tube. What should I do to correct this?

[Timtation]

Not sure if this is relative but ours needs to be burped periodically when filling. The inflow is much greater than the vent can handle so I fill for a while then shut off the water until it burps then start again. I use a filler with a shutoff valve at the hose connection.
Good luck, Tim

[TakeItEasy]

I had a hard time filling my fresh water using the fresh water fill. The water would always flow back out the fill hole. It turns out the fill hose between the filler neck and the tank was raised in the middle. This would cause water to flow back out the fill hole. My hose runs under my bed so I was able to move the middle if the hose down to fix the issue.

Not sure this is the case on yours because you are able to fill it 1/3 full before you gives you issues. Thought I would mention in it as something to check though. Good luck.