Fresh Water Tank Overflow Condition

[Wayfinder]

Has anyone taken a pic of the inside of their fresh water tank overflow, near the walk-in door?  Here's mine.  Looks like there's a metal screen falling apart.  At least my tank won't blow up like a ballon and warp the trailer. That's something. 🫣

I'm wondering if this inside piece does unscrew from what appears to be the outer ring.
 

[Ronbrink]

47 minutes ago, Wayfinder said:

Has anyone taken a pic of the inside of their fresh water tank overflow, near the walk-in door?  Here's mine.  Looks like there's a metal screen falling apart.  At least my tank won't blow up like a ballon and warp the trailer. That's something. 🫣

I'm wondering if this inside piece does unscrew from what appears to be the outer ring.
 

Good question, never thought about it. Perhaps the screen serves to keep critters out. 

[Steph and Dud B]

2 hours ago, Wayfinder said:

At least my tank won't blow up like a ballon and warp the trailer.

My wife mentioned seeing that incident on the FB page. Was a cause ever determined? I gather the overflow line did work. Too much pressure going in? Another reason to always have a pressure regulator on your hose, even when filling the tank.

[Wayfinder]

2 minutes ago, Steph and Dud B said:

My wife mentioned seeing that incident on the FB page. Was a cause ever determined? I gather the overflow line did work. Too much pressure going in? Another reason to always have a pressure regulator on your hose, even when filling the tank.

That's all I can figure happened - the overflow got blocked. Since my screen in the overflow is falling apart with rust, it's letting most of the water out fast.  I was wondering of those plastic strands, from making the tank holes, blocked that person's overflow, instead of going through the pump screen.  When I purchased my #110 used in 2021, the pump screen was full of those strands from the drill holes.  But have not seen them since.

I also got push-back that the trailers do not have built-in 40-50 lb water regulators.  Well, mine came with them in the basement, under the floor board (discovered last year when replacing check valves).  I typically push 70 PSI of house water into my fresh tank all the time.  Now I'm scared to let overflow too long just to help flush things.  So far, so good though.  Knock on fiberglass.

 

[Wayfinder]

I grabbed my borescope and not only grabbed some pics of the rusted screen in the overflow pipe, but a short video of my borescope magnet attachment trying to pull more screen out.  Some of the rotted screen simply fell out upon touching it. I got the rest out with a long angled pick.

Also, I had drained my fresh water tank on Sunday after a trip, but did not raise the nose of the camper high enough to remove enough water.  You can see the reflection of the borescope light in the water.  So I raised the rear jack stands, and raised the nose up a good bit more to drain even more water.

I bet no one has shown the inside of the water tank before.  LOL

I can now see how an old rusted screen mesh could block the overflow.  Also time to clean tank.

 

 

Edited Friday at 05:43 PM by Wayfinder
removed attached movie

[Wayfinder]

I will get an external screen cover to put around the overflow pipe, like those that cover furnace exhausts.  

[Townesw]

Reminds me of the pictures you get after a colonoscopy. 
 

Bill

[Mike and Carol]

4 hours ago, Wayfinder said:

I also got push-back that the trailers do not have built-in 40-50 lb water regulators.  Well, mine came with them in the basement, under the floor board (discovered last year when replacing check valves).  I typically push 70 PSI of house water into my fresh tank all the time.  Now I'm scared to let overflow too long just to help flush things.  So far, so good though.  Knock on fiberglass.

 

Yes, they do.  I had to replace mine a few years ago when it wouldn’t let water pass.  It was right next to the back flow valve in the back of the basement like yours.

[Steph and Dud B]

3 hours ago, Townesw said:

Reminds me of the pictures you get after a colonoscopy. 

I was thinking the same thing!

[John Dorrer]

7 hours ago, Steph and Dud B said:

My wife mentioned seeing that incident on the FB page. Was a cause ever determined? I gather the overflow line did work. Too much pressure going in? Another reason to always have a pressure regulator on your hose, even when filling the tank.

Operator error, no pressure gauge. Great posts by someone with knowledge of RV fresh water tanks, and the destructive force that has destroyed stick built trailers. This person worked for a manufacturer of tanks, including fresh water tanks for RV's

[jd1923]

20 hours ago, Wayfinder said:

Has anyone taken a pic of the inside of their fresh water tank overflow, near the walk-in door?  Here's mine.

Thank you Chris, for bring this to our attention! 😂

Every time a forum member brings up a maintenance issue, next thing I'm outside checking ours. That's for sure!

Ours has no screen at all and no rust. I can stick the full length of my index finger all the up into the opening.

Thought I better secure our drain to keep mice and bugs out. I cut a circle about 2 1/2" dia. Then cut a radius line to shape a cone. Then crushed the screen over a 3/8" socket extension and pushed it up into the opening.

Same screening I used in the fridge vents.

Edited yesterday at 09:14 AM by jd1923
Added pics

[DanielBoondock]

On 8/28/2026 at 7:28 PM, jd1923 said:

Thank you Chris, for bring this to our attention! 😂

Every time a forum member brings up a maintenance issue, next thing I'm outside checking ours. That's for sure!

Agree, I need to retire so I have the time to keep up on the forum 😅

I've been debating whether to ceramic coat the plastic bits - this tells me yes definitely worth it. Even if you don't coat the trailer, the smaller parts are super easy. Glidecoat is multi-surface, you can do fiberglass, metal, glass, plastic, and for these parts you don't need much. Just clean, you can do some light compounding/polishing with a microfiber towel if you want, or just don't bother, and apply two coats. Just get a small bottle of Glidecoat which isn't expensive, there's a 15% Labor Day sale going on. Anyhow if anybody wants to do this feel free to ping me for help

Edited 1 hour ago by DanielBoondock