vent pipe for fresh water

cleojayco wrote:
Thanks for the info what do I need to do to get the image that you refer to

Simply right click the picture and print or save it.

bpounds wrote:
If we are talking about a gravity fill port, the problem is often with the fill hose itself, not the vent. The fill hose needs a good slope to it, and if there is a low spot, or if it is simply too long, filling will be slow. There may not be much you can do to change the hose. What helps is to slide your garden hose down the fill port. They sell a short piece of vinyl hose for that, and they work well because it is very flexible, or you can just make your own with an old piece of white water hose but that will be stiffer. Either way, the goal is to keep the stream of water flowing fast through the low point.

There can be a problem with the vent hose, but less likely. If it has a low point, it can be blocked with water sitting there. All it needs is to be blown out. But that's rarely the real problem. Air has to come out obviously, but it doesn't take a large hose to pass a lot of air.

^^^^ This!
Mine had a very low location for the gravity fill/vent port & city water connection - it was so close to floor level that it was nearly impossible to get the tank fill hose on/off of the fitting. Both the fill and vent hoses were intertwined around each other, and both had to go up and over the base of the cabinet into the next before going down through the floor. The fresh water tank was immediately below the floor. There was no, NONE, slope and the up and down created low spots in the vent for water to get trapped and block it. Filling the fresh water tank was nearly impossible. I tried straightening out and untangling the hoses with no improvement. The truth is, water MUST run downhill!

I found a much higher location above the existing gravity fill, purchased and installed a new gravity fill/vent fitting about 24" above the factory fitting. I moved the vent and fill hoses up to the new level, rerouting and untwisting them so each had a straight shot down to the point where they went through the floor to the tank. I blocked off the now unused original gravity fill fittings.

Now the water goes in without any problem, and you can feel the air venting from the tank throughout the whole filling process. I still use the filling attachment with the short clear tube and shutoff valve to prevent splashing out at full water flow.

If you have

If we are talking about a gravity fill port, the problem is often with the fill hose itself, not the vent. The fill hose needs a good slope to it, and if there is a low spot, or if it is simply too long, filling will be slow. There may not be much you can do to change the hose. What helps is to slide your garden hose down the fill port. They sell a short piece of vinyl hose for that, and they work well because it is very flexible, or you can just make your own with an old piece of white water hose but that will be stiffer. Either way, the goal is to keep the stream of water flowing fast through the low point.

There can be a problem with the vent hose, but less likely. If it has a low point, it can be blocked with water sitting there. All it needs is to be blown out. But that's rarely the real problem. Air has to come out obviously, but it doesn't take a large hose to pass a lot of air.

Lynnmor wrote:

RoyB wrote:
I was always having a hard time holding up my 5-gal jeri can when filling my off-road Popup fresh water tank. Seems like it would take forever to empty the 5-gallons haha... We always like to camp off-grid with no city water hookups.

I finally rigged up a 12VDC water pump for boats from WALMART and now all I do is stick a tube down into the jeri can and it empties into the fresh water tank in a breeze now...

Roy Ken

Or you could have added a tee and a check valve and drawn the water in with the current pump, wiring and switch. Nothing to store, simple and cheap.

If you have an outside shower you can just draw water out of a Jerry can using the winterize suction hose (set valve like you're putting in antifreeze) and stick the outside shower in the water fill opening.

I installed a check valve in the fresh water tank overflow to get the maximum amount of water in without causing a syphon effect. Also to refill while dry camping, I use one of those blue hard side water 5 gallon cans from Walmart, unscrew the little fill valve in the lid and screw in a standard water hose. It works wonders.

Thanks for the info what do I need to do to get the image that you refer to

Leave your pump off but open all cold water faucets in the RV.

Diagram for plumbing so that pump can draw in water from a container. The check valve in the city is removed and an inline check valve is added downstream. A short hose is connected to the city water port and goes to the container.

Lynnmor wrote:

RoyB wrote:
I was always having a hard time holding up

Or you could have added a tee and a check valve and drawn the water in with the current pump, wiring and switch. Nothing to store, simple and cheap.

Lynnmor - I thought about that. I already have a tee on the input end with a short hose to stick down a container for winterizing... Would have to put the TEE in the output side of the on-board water pump.

It was just as easy to do what I did haha... This way I can fill the jerican at the water source if I need to... All stores in my truck... We don't cook or drink out of our fresh water tank - always bring along bottled water for that as well as making our favorite water taste for fresh ground coffee bean coffee maker.

Roy Ken

What I have found is that the vent system is often too small to offset the volume of water being pumped in thru the fresh tank fill. You end up with water coming back out the filler port and the vent hole.

When this happens I use my air compressor and force air thru both the vent and filler holes. This clears both lines and I can start filling again. I might have to do this a couple times when filling the tank.

Using lower pressure to fill the tank also helps.