Fresh water tank

[Gracie52]

I am trying to fill the fresh water tanks in a Jayco 28 RLS and I put very little water in and then it starts coming out a white tube handing down underneath the trailer and leaving the indicator light on E....what am I doing wrong?

[WinnieView]

Please ensure the fresh water tank drain valve is closed.

[T&M_Texas]

Originally Posted by Gracie52

I am trying to fill the fresh water tanks in a Jayco 28 RLS and I put very little water in and then it starts coming out a white tube handing down underneath the trailer and leaving the indicator light on E....what am I doing wrong?

Page 117

Using the Gravity Fill (If So Equipped)

You can fill the fresh water tank from a container of fresh water and the gravity water fill

inlet if you do not have access to City Water.

The gravity fill will have a potable water label next to it. Do not remove this label.

Low point & fresh water tank drains should be closed.

1. Remove the connection cap and insert a non-toxic drinking water hose (or a funnel)

into the gravity fill inlet. The other end of the hose goes into a container of fresh potable

water.

2.

Pour the fresh water into the gravity fill until the tank is full.

3. Open both the hot and cold water faucets, along with outside shower faucets (if so

equipped) when filling the fresh water tank to allow air pockets to be forced out of the

system.

4. When the fresh water tank on the RV is full, remove the non-toxic drinking hose and

container from the gravity water fill. Replace the connection cap. This cap should

always be installed if the water fill is not in use.

[Gracie52]

I see drain valves which are closed. Would the fresh water tank valve be on the side or underneath?

[RogerR]

Usually the fresh water tank drain is as near to the tank as possible.

The low point drain may be somewhere else to make sure all the lines are drained. There are usually two low point drains, one for hot, one for cold. Mine are in the space that also holds the 12 volt water pump.

You can check to see if the low point drains are closed by hooking up to city water and purging your sink(s), shower, toilet, etc. If water is coming out a little pipe or both little pipes on the bottom start exploring for the shut offs.

If you are like me, I put a big label on them to remind me in the future. This is also a time to find your hot water heater bypass valves and purge the hot water heater of any crud and stale water. If you are going dry camping this is a good time to fill the hot water heater so you don't have to use up tank water when you get there. You might also consider checking that it lights before you leave home.

[redsnapper]

My unit has two white hoses, for what I understand, are overflow hoses. Tankage is 80 gallons and specs say "two tanks for fresh" yet with a common fill port.
This is not the single white petcock low point drain valve.

I would fill up the fresh tank (it overflowed out the fill port) idiot red light said full.

Hit the road and get to my destination and bam...….indicator light at 2/3rds.

I just folded over both of those hoses and held them closed with a zip tie.

No more overflow.....no more 2/3ds full tank on arrival.

Not sure my unit is the same as others, but when I got behind the jack knife sofa in the rear, the fill line was routed UP and over a thin plywood partition.
Using a standard garden hose end for fill up, the water would not get up and over that rise and kept spilling out of the fill cap.

Even a longer adaptor hose end, a Camco one I believe, it was the same problem, as that extension was not long enough to get over the hump.

I finally bought the shortest length of cheap 1/2" hose I could find.
Cut it off to give me a 3" length.
I could snake that length up and over the partition and fill as normal.

[RichR]

I believe the white hoses are overflow/vent pipes. Jayco has a wierd way of venting their tanks according to the various reports that I have seen. What I think is happening is as the tank is being filled the overflow pipes start to syphon the water from the tank. That indicates that the pipes are inserted to the bottom of the tanks, they should only dip into the very top of the tanks. To complicate things those pipes need to be kept open so air can be pulled into the tanks as water is pumped out. Otherwise a vacuum will be created which will make the pump labor to get water out and also attempt to colapse the tank. Tha's not good. Most tanks have a top mounted vent which has a hose that connects to little vent opening beside the fresh water fill port. There will be no siphoning with this hookup and the pump will be working without resistance. Jayco needs to go take a physics class.


Maybe filling the tanks at a slower rate will help, in that, air in the tanks will be able to escape via the fill pipe and not allow the syhoning to set up. I have the same setup and fill the tanks from our water well that flows a slow rate and I have had no problems so far. It takes about a half hour the fill the tanks.

[redsnapper]

Originally Posted by RichR

. To complicate things those pipes need to be kept open so air can be pulled into the tanks as water is pumped out. Otherwise a vacuum will be created which will make the pump labor to get water out and also attempt to colapse the tank.

Maybe filling the tanks at a slower rate will help, in that, air in the tanks will be able to escape via the fill pipe and not allow the syhoning to set up. I have the same setup and fill the tanks from our water well that flows a slow rate and I have had no problems so far. It takes about a half hour the fill the tanks.

The water fill port cap on mine is not sealed up with an air tight gasket. Air and water can get out. Not sure that would allow a vacuum to set up or not.. Seems unlikely.
My dilemma with the "slow" fill is.....the water flow cannot get over the rise in the hose fill line. That rises up from the fill port level (uphill), and over the thin plywood partition below the jack knife sofa.

I needed either a "snake" hose, or full blast pressure to get over the hump.
I chose the hose.

The short hose length can snake over this rise and fill the tanks as normal.

Haven't had any problems yet with the overflow hoses being kinked up and tied off.


Engineering indeed

[Sunflake]

I could never get our 80 gallon tank to get above 1/2 full before it came out of the 2 overflow/vent hoses. Then driving the siphon effect happened sucking even more out. So I plugged both pipes and filled the tank making sure the little screened breather by the fill cap was pushing air out. Has worked perfect and when I have to fill it before I leave I get there with all 80 gallons.

[redsnapper]

Originally Posted by Sunflake

I could never get our 80 gallon tank to get above 1/2 full before it came out of the 2 overflow/vent hoses. Then driving the siphon effect happened sucking even more out. So I plugged both pipes and filled the tank making sure the little screened breather by the fill cap was pushing air out. Has worked perfect and when I have to fill it before I leave I get there with all 80 gallons.

Exact same experience...…
The water would glug glug out the fill port, I assumed it was full...water poured a full stream out those overflow hoses, further telling me it was full.

Idiot light said half full.

Ended that nonsense with the "snake" effect hose to get it deeper into the fill inlet hose and up and over the plywood partition.
Bent over the overflow hoses and zip tied them bent.
No more overflow.....

Now with the glug glug of water coming out the fill port, it's full and the idiot lights show 4 reds.
Bingo!!

[Sunflake]

No idea why those 2 overflow hoses are even needed. Tanks forever have just had the breather by the fill port.

[redsnapper]

Originally Posted by Sunflake

No idea why those 2 overflow hoses are even needed. Tanks forever have just had the breather by the fill port.

I too am at a loss of why they exist.

The fill port is not air/water tight, so some vacuum effect is a non issue, as best as I can determine.

[oldmanAZ]

Originally Posted by Sunflake

No idea why those 2 overflow hoses are even needed. Tanks forever have just had the breather by the fill port.

IMO, 3 reasons come to mind:
- To protect us from ourselves if someone fills the tank(s) with a oversized hose that blocks the vent at the filler.
- If the vent at the filler is sufficient when pumping water out of the tank, but may not be able to vent fast enough when filling.
- The water tank manufacturer won't warranty the tank if the vent is not installed.

[RichR]

I think the problem is that the vent tubes were inserted to far into the tanks as a result of poor workmanship. There is nothing wrong venting the tanks like that if the hoses terminate just inside the top of the tank to prevent siphoning.
There are many other posts on this subject that I have seen. Maybe doing a search on these will dig up a simple solution.
One bad thing about those overflow tubes is there is nothing to prevent little critters from entering the tanks. There should be a screen or something that can block their entrance.

[Bakerron]

Originally Posted by Gracie52

I am trying to fill the fresh water tanks in a Jayco 28 RLS and I put very little water in and then it starts coming out a white tube handing down underneath the trailer and leaving the indicator light on E....what am I doing wrong?

Open a faucet inside the trailer to let air out as you add water.

[rockaw]

hmmm, I have a 28RLS with 80 gal tanks..
First, I've never had a problem just putting a drinking hose in the fill and filling it unitl the water flows out the overflows and I've always had 4 lights.


There are 2 overflows, one for each tank, not all campers have the double tanks, I think it was just an easy way, have the mass production tanks with the overflow already in and if installing the second tank, just hook them together and not worry about disconnecting one overflow.


You have the 2 overflow drains and 2 other low point drains. Make sure the low point drains are closed, if not, they will start draining as soon as you pout water in and you're not mixing up the drains with the overflow, the overflow should not drain unless the tank is full......
(not going out to look tonight) I believe the overflow drains are on the left side where your slideout is and the low point drains should be on the door side.