Fresh water tank fill problem

Are you certain the tank was empty to begin with? You can't put 50 gals in if it already has 20 gals. Lots of tanks out there that won't fully drain.

I'm a fan of actually looking at the FW tank. Most are translucent so you can see the water level. Also review how the inlets and outlets are positioned and how the plumbing is laid out.

Thanks everyone for the tips and info. I will continue to work on this with your suggestions, I am considering going to a gravity fill instead of standard hose fitting.

Do you have an internal valve that fills the water tank when hooked up to the city water supply? Mine works either way without problems.

BBrownCG17 wrote:
I have a new 2015 Heritage Glen 282rk, my fresh water tank is 52gal. cap. I can only get about 25 gal in it before I start having water come out the vent,

Are you using a "hose extension" that goes about 18 inches into the neck ?? Most are clear plastic tubing with their own shutoff valve to regulate the flow.

That helps a lot.

I can generally go full blast to about half full and then must throttle it down to half flow or less for another 15 minutes or so. I also suspect that my tank only really holds about 80 percent of it's advertised capacity......and splashes a little bit out of the vent when going down the road too.

While it's a common problem, if you continue to only get a 50 percent fill......see your dealer.

WayneAt63044 wrote:
The problem like that on my FW tank is that the fill connection (not gravity feed) and vent are at nearly the same place on the side of the tank. I raised the vent hole where it exits on the side of the trailer to a level above the FW tank by removing the outside shower and extending the vent exit hole to that space. Now it won't siphon out. Previously, the siphon action would happen running down the road. I would fill the tank at home and only have half a tank left when arriving at a campground an hour away.

Many thousands of trailers were built with vent hoses attached at the top corner of the tank and go down towards the road. These hoses would simply spill water out while rounding a curve. Few people know they have a problem even though they arrive at their destination with little water remaining in the tank. BTW, it's not a siphon action, it is simply a spill.

The OP has a different problem. Filling slowly may help. The vent hose should be checked to see if there is any sag or restriction in it.

The problem like that on my FW tank is that the fill connection (not gravity feed) and vent are at nearly the same place on the side of the tank. I raised the vent hole where it exits on the side of the trailer to a level above the FW tank by removing the outside shower and extending the vent exit hole to that space. Now it won't siphon out. Previously, the siphon action would happen running down the road. I would fill the tank at home and only have half a tank left when arriving at a campground an hour away.

Fill the tank much slower. This is a common problem. The only solution is to take the time and fill slower.

Edit:
What's happening is, the water is entering too fast, causing a vapor (air) lock. One of 2 ways to over come this. When it starts to flow back up out the fill hole, wait a few minutes for the water to clear and then continue filling.

or

Fill the tank much slower, so there is always air coming back out the fill hole. I have found my vent is pretty much useless. I don't know why, but when filling slower, I don't have that problem. Like you, I tried blowing out the vent with my air compressor. It's clear. But simply slowing the water flow down when filling is the easiest solution.