Water leak from filling fresh tank!

TimmyB · 09-25-2019, 12:30 AM

We are on our first major excursion with our rig and before we left, I filled the fresh water tank to the top. Actually, I overfilled it, but that is no problem as the water just spills out the side of the coach. Before you know it, we had water all over the floor by the edge of the passenger side bed, the heater, the fridge, etc. We dried it up, but it kept coming for a few days into our trip, so I emptied the tank. A day later, I added about a half tank. Miles down the road, the same problem!

We have checked everywhere that we can see, including taking off the cover underneath our closet. We can find NO leak. I even checked by adding a little more water to make sure that there was no leak in the fill hose. The tank is dry on the sides and at the bottom, with no evidence of water damage around it. I have traced the blue Pex-style water lines all the way to the pump and out of it with no luck. I turned the water on to see if running the pump might show me something, but nothing out of the ordinary happened.

Has anyone else had this or heard of this? I've got about a third of a tank right now and it seems to be happy.

MJC62 · 09-25-2019, 01:25 AM

Are you parked? Can you fill the tank by degrees to see at what level it starts to leak? I was told long ago by an old RV sage that overfilling the tank is taboo as the tank is not designed to be pressurized. Though an overfill is not technically pressurizing the tank an overfull tank is expanded beyond its design limit and could rupture. Sounded logical to me so we always leave the water a couple inches short of the top of the tank. I hope a rupture is not the case and perhaps a loose fill or overflow hose is your issue. Also check the outlet on the drain side of the tank. Good luck with the search perhaps someone with your model can help track it down. Mark

mountainsam · 09-25-2019, 02:20 AM

TimmyB, do you notice if your pump is running at all when you are not using water. Sounds like you could have a slight leak in a hose. Best guess, how much water would you say is on the floor after a few hours? Second of all could it be condensation from the fridge? You may want to check the hose on the condensation pan.

TimmyB · 09-25-2019, 02:32 AM

Quote:

Originally Posted by mountainsam

TimmyB, do you notice if your pump is running at all when you are not using water. Sounds like you could have a slight leak in a hose. Best guess, how much water would you say is on the floor after a few hours? Second of all could it be condensation from the fridge? You may want to check the hose on the condensation pan.

No, no extra pump running. Again, have checked every hose as far as I can and can find nothing.

Didn't know about the condensation pan. I'll try to investigate that but not sure exactly what I'm looking for!

Thanks.

TimmyB · 09-25-2019, 02:34 AM

Quote:

Originally Posted by MJC62

Are you parked? Can you fill the tank by degrees to see at what level it starts to leak? I was told long ago by an old RV sage that overfilling the tank is taboo as the tank is not designed to be pressurized. Though an overfill is not technically pressurizing the tank an overfull tank is expanded beyond its design limit and could rupture. Sounded logical to me so we always leave the water a couple inches short of the top of the tank. I hope a rupture is not the case and perhaps a loose fill or overflow hose is your issue. Also check the outlet on the drain side of the tank. Good luck with the search perhaps someone with your model can help track it down. Mark

Yeah, I can't find any sign of a rupture or hose leak anywhere! I have checked every place that I can see. That's what bothers me the most. I should be able to see something with this much water.

Thanks.

**16ACE27** · 09-25-2019, 03:24 AM

Quote:

Originally Posted by TimmyB

No, no extra pump running. Again, have checked every hose as far as I can and can find nothing.

Didn't know about the condensation pan. I'll try to investigate that but not sure exactly what I'm looking for!

Thanks.

No condensation pan with an absorption fridge.

How about the tank vent? Is it attached to the fill nozzle as it should be or maybe just flopping around?

TimmyB · 09-25-2019, 03:39 AM

Quote:

Originally Posted by 16ACE27

No condensation pan with an absorption fridge.

How about the tank vent? Is it attached to the fill nozzle as it should be or maybe just flopping around?

No, I actually had a problem with a pinched vent tube a few weeks back. I had to cut a couple of inches off of it to fix it. While I was in there, I trimmed about eight inches off the fill tube as well, because it was hanging down below the fill port and trapping water in there which was never going to reach the tank. That's why I checked those today, to make sure I hadn't created another problem with my fix.

mountainsam · 09-25-2019, 04:42 AM

Actually my refrigerator does have a condensation pan. It is located on the inside back wall under the freezer. It has a tube running out the back accessed by removing the outside refrigerator panel. It is a three way absorption fridge.

GVP-The Boxcar Children · 09-25-2019, 05:46 AM

Perhaps there is a crack in the fresh water tank itself at a certain height?
GVP

sandrooney · 09-25-2019, 09:54 AM

Check how the winterizing system is plumbed. They didn't install mine correctly and water siphoned out one of the lines.

blw2 · 09-25-2019, 11:20 AM

the vent tube on my tank was a bit loose....but I caught that before it ever leaked.

I did have a leak early on. The strainer on the suction side of the pump had a hairline crack in the cap's plastic threads from over tightening. This was found in the first day or two...so either factory or dealer. It was impossible to see the crack and was a bit hard to find.

Doesn't seem like it's your overflow...so I'm thinking cracked fitting....maybe an elbow or something

blw2 · 09-25-2019, 11:21 AM

meant to add...on the suction side so not as obvious as a pressure leak.

JamieGeek · 09-25-2019, 11:23 AM

Our strainer was loose causing a leak where you're talking. A quick turn on the cap tightened it up and no leaks since.

The Gritz Carlton · 09-25-2019, 12:49 PM

Quote:

Originally Posted by GVP-The Boxcar Children

Perhaps there is a crack in the fresh water tank itself at a certain height?
GVP

My thoughts exactly! A small crack that holds when little water is in tank. As tank fills and "bulges", it opens crack up a tad allowing leak.

TimmyB · 09-28-2019, 02:18 AM

OK, thanks for the leads, gang! We have been having a blast in Denver and SLC and being on city water for all of this time, haven't had a chance to test out any theories! I'll look at it soon, but at least I have some good suspects.

cbach · 10-02-2019, 06:51 PM

I had two similar leaks on my new Magnitude, one was the clamped connection on the spiral fill hose on the tank, and one was a small void in a glued joint on the tank drain line that only leaked under high head pressure when the tank was full. Water would seep under the tank and exit at the front left corner (lowest point), which made it seem like the tank was the culprit.

Junodtim · 10-02-2019, 07:02 PM

This is what happened to our 2019 RC25. The tank was held with loose nylon strap. While the tank was nearly empty bouncing through pot holes and road construction on I10, the tank moved enough for 1/2" connector supplying the pump to rub against the pump and the water line connector came loose. I emptied the tank, pushed it as far right as I could, and used an old screw driver and twisted that screw driver to tighten the strap. I used zip ties to secure the screw driver in place. Tightened all the water connections and refilled the tank. All is good.

Dafabs · 10-02-2019, 10:50 PM

We had a simaler problem. Thefiller hose was loose and the cabin flooded when we tried filling the frsh water tank. We reconnected the hose and all is good.[W=TimmyB;204030]We are on our first major excursion with our rig and before we left, I filled the fresh water tank to the top. Actually, I overfilled it, but that is no problem as the water just spills out the side of the coach. Before you know it, we had water all over the floor by the edge of the passenger side bed, the heater, the fridge, etc. We dried it up, but it kept coming for a few days into our trip, so I emptied the tank. A day later, I added about a half tank. Miles down the road, the same problem!

We have checked everywhere that we can see, including taking off the cover underneath our closet. We can find NO leak. I even checked by adding a little more water to make sure that there was no leak in the fill hose. The tank is dry on the sides and at the bottom, with no evidence of water damage around it. I have traced the blue Pex-style water lines all the way to the pump and out of it with no luck. I turned the water on to see if running the pump might show me something, but nothing out of the ordinary happened.

Has anyone else had this or heard of this? I've got about a third of a tank right now and it seems to be happy.[/QUOTE]

TimmyB · 10-03-2019, 12:21 AM

More good leads. Thanks, everyone!

The good news is we have been almost exclusively on city water for our journey so far. Tonight, at Mesa Verde, being the exception. We filled only 1/3 full before we left Zion and watched very carefully for any signs of leaks. So far, none have happened.

carlgorski · 10-03-2019, 01:30 AM

Quote:

Originally Posted by MJC62

Are you parked? Can you fill the tank by degrees to see at what level it starts to leak? I was told long ago by an old RV sage that overfilling the tank is taboo as the tank is not designed to be pressurized. Though an overfill is not technically pressurizing the tank an overfull tank is expanded beyond its design limit and could rupture. Sounded logical to me so we always leave the water a couple inches short of the top of the tank. I hope a rupture is not the case and perhaps a loose fill or overflow hose is your issue. Also check the outlet on the drain side of the tank. Good luck with the search perhaps someone with your model can help track it down. Mark

Tanks have overfill hose. doesn't hurt to fill till water comes out. I have no way of knowing anyway, tank is hidden.

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