Fresh water tank question

**hoosierguy** · 07-04-2012, 09:56 AM

This question is for you experienced 5th wheel or travel trailer owners.............

I filled the fresh water tank this morning for the first time since we purchased our 2012 36RL. I previously had seen that there were a couple of blue stub water lines protruding about 4 inches through the bottom pan cover of the trailer. After filling the tank for about 22 minutes, I started observing water flowing out of the rearward tube. It continued to flow for about 10 minutes after I turned off my water supply. I assume this must be an overflow line. The second tube, towards the frontof the trailer,has a petcock valve on it, so, I assume this must be a fresh water tank drain line. Are my assumptions correct?

KR2011 · 07-04-2012, 10:46 AM

Yes you are correct. You may also have a second overflow tube for the fresh tank.

Tall-Pines · 07-04-2012, 11:17 AM

I had filled my tank and noticed the same thing ...

I then added a 1/2 cup (or so) bleach into the tank left if for a half hour or so and then drained the tank via the drain valve - as the system is both new and was pre-filled with non-toxic anti-freeze so I want to sanitize the system.

**hoosierguy** · 07-04-2012, 12:15 PM

Quote:

Originally Posted by KR2011

Yes you are correct. You may also have a second overflow tube for the fresh tank.

Apparently I just discovered the second overflow. I was disifecting the tank and refilling for a second time and forgot about it while I was off doing another task. When I remembered to check, two water streams were coming out the bottom of the trailer. The second is a short section of white water hose. I had thought that that hose was for the hot water heater, but, I now see that there are two other petcock valves under the water heater area.

Thanks for your response.

wvpel · 07-04-2012, 04:26 PM

We had a similar experience but with a different cause. The day after picking up our 2012 31SL from the dealer in April, I noticed water dripping from bottom of rv. Dealer said must have overfilled it. Continued to drip. Took it in and they found that the fresh water tank had been punctured with a screw at the factory. When the screw was backed out, water poured. Had to get a new tank (more than a week).

5th_Time · 07-04-2012, 08:45 PM

I haveposted this question previously, also.

The part I don't understand is how the overflow tube can flow a solid stream of water for 10+ minutes afterward an overfill. Where would it store that volume of water?? Plus, water never flowed out at the inlet area as I've heard it'ssupposed to.

Is it possible that once theoverflow begins, it isactually siphoning water fromthe tank?

Hoosierguy, the petcocks you see below the waterheater are actually low-point drain vales to drain the hot and cold sides of the entire fresh water system.

Edited by: 5th_Time

mhs4771 · 07-04-2012, 10:40 PM

We wondered the same thing. Was filling the fresh water for a dry camping weekend. Guage reached full and water began flowing out the rearward overflow tube. Remove the filler hose and as you noted, a steady stream of water flowed for a long time. Checked the idiot guage and now down to 2/3. So we put the filler hose back in, but reduced the flow rate and was able to add quite a few more gallons of water and stopped before it began flowing out the overflow this time. It almost acts as if there is a check valve on the overflow tube and once tripped dumps appox a 1/3 of the water before resetting. Any thoughts from others??

lillyputz · 07-05-2012, 08:27 AM

Quote:

Originally Posted by mhs4771

We wondered the same thing. Was filling the fresh water for a dry camping weekend. Guage reached full and water began flowing out the rearward overflow tube. Remove the filler hose and as you noted, a steady stream of water flowed for a long time. Checked the idiot guage and now down to 2/3. So we put the filler hose back in, but reduced the flow rate and was able to add quite a few more gallons of water and stopped before it began flowing out the overflow this time. It almost acts as if there is a check valve on the overflow tube and once tripped dumps appox a 1/3 of the water before resetting. Any thoughts from others??

I think was is happening is to much water pressure and or volume going into the tank. causing a lot of air pressure and pressurizing the tank. I had this problem on our last 5th wheel. if I let the water flow about half as fast, it took longer to fill, but did not loose water through the over flow or burb back through the filler.

Lillyputz

Tall-Pines · 07-05-2012, 09:31 AM

Instead of wondering where the plumbing runs or where the power lines run ... is it possible to get plumbing/electrical/HVAC diagrams from Redwood?

Surely these must be available for the factory floor ... and available for the dealer and/or end user or owner?

lillyputz · 07-05-2012, 10:24 AM

Quote:

Originally Posted by lillyputz

Quote:

Originally Posted by mhs4771

We wondered the same thing. Was filling the fresh water for a dry camping weekend. Guage reached full and water began flowing out the rearward overflow tube. Remove the filler hose and as you noted, a steady stream of water flowed for a long time. Checked the idiot guage and now down to 2/3. So we put the filler hose back in, but reduced the flow rate and was able to add quite a few more gallons of water and stopped before it began flowing out the overflow this time. It almost acts as if there is a check valve on the overflow tube and once tripped dumps appox a 1/3 of the water before resetting. Any thoughts from others??

I think was is happening is to much water pressure and or volume going into the tank. causing a lot of air pressure and pressurizing the tank. I had this problem on our last 5th wheel. if I let the water flow about half as fast, it took longer to fill, but did not loose water through the over flow or burb back through the filler.

Lillyputz

After this quote. I went out and filled ours for the first time. can't keep tank full. the water flows out the over flow tube, will under the 2/3 mark. e-mailed Brian.

5th_Time · 07-05-2012, 11:13 AM

LP: Let us know what Brian says ASAP because mine does what yours is doing no matter how slow I fill it. I need an answer to this issue.

KR2011 · 07-05-2012, 09:00 PM

We live on our fresh water tank as we do not have the luxury of full hook ups where we are, I have found that if you fill the tank to fast it builds pressure faster than the over flow tubes can get rid it so when the tank gets so full that water is flowing out of the overflow tube it takes time for the pressure to equalize and that is why it seems to flow out of the overflow tube for a while. I have collected the water coming out of our overflow tube and found that we are loosing about 2.5 gallons of water out of the tube after it starts to flow.

lillyputz · 07-05-2012, 09:01 PM

Quote:

Originally Posted by 5th_Time

LP: Let us know what Brian says ASAP because mine does what yours is doing no matter how slow I fill it. I need an answer to this issue.

Brian said, he ran accross a couple of units doing this. he thinks the tank is getting a vacuum. Sothey put the vent in at a incline so the air will push out and not the water.

I sent another e-mail and asked what is the fix. By they, I think he means another trip to the dealer for repairs. I'll let you know.

Lillyputz

Tall-Pines · 07-05-2012, 09:47 PM

Seems to me to be setting up a siphon. If the overflow line is completely full and the opening is lower than the tank ... bingo ... siphon occurs. Only way to break the siphon is to get air into the system.
I'm thinking that you typically fill the tank with the hose and as soon as it is full, you connect the hose back onto the city connection and energize ... no air in the system and it is setup for the siphon.
So, what if before you fill, you ensure the pump is off and bleed off some water from the system to both reduce system pressure and introduce some air.
Just rambling ... the engineer in me ...

KR2011 · 07-05-2012, 10:01 PM

Quote:

Originally Posted by Tall-Pines

Seems to me to be setting up a siphon.Â* If the overflow line is completely full and the opening is lower than the tank ... bingo ... siphon occurs.Â* Only way to break the siphon is to get air into the system.
I'm thinking that you typically fill the tank with the hose and as soon as it is full, you connect the hose back onto the city connection and energize ... no air in the system and it is setup for the siphon.
So, what if before you fill, you ensure the pump is off and bleed off some water from the system to both reduce system pressure and introduce some air.
Just rambling ... the engineer in me ...

The water pump sucks the water from the tank it does not put pressure in the tank. On my FL the overflow tubes come off the top so if I am filling my tank to the point of coming out of the overflow than my tank is to full and the overflow tubes are doing there job and that is to relieve the pressure from filling the tank.

**Dave&Ginny** · 07-05-2012, 10:14 PM

Quote:

Originally Posted by lillyputz

Quote:

Originally Posted by 5th_Time

LP: Let us know what Brian says ASAP because mine does what yours is doing no matter how slow I fill it. I need an answer to this issue.

Brian said, he ran accross a couple of units doing this. he thinks the tank is getting a vacuum. Sothey put the vent in at a incline so the air will push out and not the water.

I sent another e-mail and asked what is the fix. By they, I think he means another trip to the dealer for repairs. I'll let you know.

Lillyputz

That could lead to at least 60 days of service for you. I think I'd wait until winter to take the trailer to the dealer.....that way you wouldn't have to pay a storage fee through winter

Tall-Pines · 07-05-2012, 10:31 PM

Hmmm .... so no system pressure on the tank and it is filled with an open hose so there cannot be any additional pressure on the tank other than the weight of the water. Depending on the stiffness of the tank, it would take very little removal of water to reduce any pressure.
Once the overflow kicks you might expect a cupful or two ... but 2.5 gallons!!! Has to be a siphon and it could indeed be causing a vacuum in the tank if the vent is not working because the vent line is full of water

Is the fill line to the tank also used as the vent line? Nah, couldn't be ... when you fill 104 gallons into the tank ... 104 gallons of air has to be released ... wonder where it goes? Heheh ... fun stuff! Sorry, not trying to make fun of the problem ... just enjoying the dialog!

**Dave&Ginny** · 07-05-2012, 10:45 PM

I haven't tried to fill my water tank full yet....I guess I better have a glass of Jack in my hand to better ponder the problem when I do. It sounds like I can water the lawn and fill my tank at the same time.....how ingenious mmmmmmmmmmm.

Dan · 07-05-2012, 11:25 PM

yup mine did the same and yes when I filled with a slower rate no problem,

on another note I do find that the inverter is nosey

lillyputz · 07-06-2012, 09:22 AM

Quote:

Originally Posted by Tall-Pines

Hmmm .... so no system pressure on the tank and it is filled with an open hose so there cannot be any additional pressure on the tank other than the weight of the water. Depending on the stiffness of the tank, it would take very little removal of water to reduce any pressure.
Once the overflow kicks you might expect a cupful or two ... but 2.5 gallons!!! Has to be a siphon and it could indeed be causing a vacuum in the tank if the vent is not working because the vent line is full of water

Is the fill line to the tank also used as the vent line? Nah, couldn't be ... when you fill 104 gallons into the tank ... 104 gallons of air has to be released ... wonder where it goes? Heheh ... fun stuff! Sorry, not trying to make fun of the problem ... just enjoying the dialog!

Brian said the fix is. the over flow tube needs to extend upward, like a vent pipe, then back down. this way it will vent but not drain the tank.

Another trip to the dealer.

Lillyputz

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