Fresh Water Holding Tanks Overflowing

skiprace

Member
Joined
Jul 26, 2023
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28
Location
McKessport
Got into the campground last night and connected to city water. When we got up this morning there’s water coming out of the fresh water holding tank overflow. We turned off the city water and now using water from holding tanks. I am assuming there’s a check value somewhere. Does anyone know if and where the check valve is? We have a Jayflight 24RBS.

We partially filled fresh water tank a couple of days ago because we stayed at a Harvest Host on our way down.

Thanks.
 
Got into the campground last night and connected to city water. When we got up this morning there’s water coming out of the fresh water holding tank overflow. We turned off the city water and now using water from holding tanks. I am assuming there’s a check value somewhere. Does anyone know if and where the check valve is? We have a Jayflight 24RBS.

We partially filled fresh water tank a couple of days ago because we stayed at a Harvest Host on our way down.

Thanks.

Your water pump has a check valve and that fails often. When that check valve fails there’s nothing stopping the city water from going through the pump and into the fresh water holding tank and filling it up then ultimately out the overflow. You can either rebuild your water pump or replace it. This has happened to me.
 
Got into the campground last night and connected to city water. When we got up this morning there’s water coming out of the fresh water holding tank overflow. We turned off the city water and now using water from holding tanks. I am assuming there’s a check value somewhere. Does anyone know if and where the check valve is? We have a Jayflight 24RBS.

We partially filled fresh water tank a couple of days ago because we stayed at a Harvest Host on our way down.

Thanks.
I don't recall the freshwater connection being linked to filling the freshwater tank on any of my Jayflight TTs. Is water coming from the petcock drain for the actual freshwater tank that possibly got hit and turned a bit allowing water to trickle out? Does your freshwater pump work and cycle off when all the faucets are closed? It may be backfilling the tank thru the pump line due to some issues with pump in baffles and internal check valve.
 
You've connected the water supply to your tank fill and obviously didn't shut off when full. There's two separate water inlets on my Jayco, one for tank fill the other for city connect or on some RV's one inlet and a lever to switch from tank fill or city connect.
 
Thanks I turned off the city water and the water stopped coming out of overflow. I’ll have to pick up a new value when I get home.
 
I have a tube that comes from freshwater tank. This is where water is coming from. There’s no water coming from drain values. I’ll find the check value and replace it.

Thanks
 
Either I'm not getting it or you aren't :) Not sure what a check valve has to do with it? While filling your fresh water tank thru the proper inlet, (not the city inlet) watch your gauge and shut water off when tank is almost full and then you use your water pump for water. Maybe you have a different/weird system where you rely on a check valve to shut water off once tank is full? When set up at a campsite with a pressurized water tap like I think you had, connect your hose from that tap to your city fill and leave on...no water should enter the fresh water tank and overflow...you don't need your water pump in that set up.
 
I have a city water connection and a separate fixture to fill holding tank.

Thanks
Normally the freshwater fill does not allow you to connect a water hose up to it and turn on the spigot with constant water pressure. If this is the case then I can see why the water runs out of the overflow lines under the camper when the tank had gotten filled. I have looked at tons of the Jayco RB TTs and the ones that I have seen do not have a valve that you can switch and automatically fill your freshwater tank.

So there are only two conclusions here. You have an issue with backfilling your tank thru the main feed line to all of your camper waterlines that is connected thru your pump. Or its possible that you mistook the freshwater hookup.
 
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One other possible issue - do you have a shower bypass that dumps water back to the fresh tank? This valve could be set in the wrong position.

I wouldn't suspect the check valve in the pump because the lines would also lose pressure when the pump is on and the pump would keep cycling as the pressure drops, although I guess it's possible that the pressure from the pump isn't high enough to do that. What is the water pressure like at the CG? Are you using a pressure regulator on the FW hose?
 
There's no question he hooked up the campsite pressurized hose to the fresh water tank fill inlet connection and didn't shut it off, hence overflow. See @ #4 & 8 :)
 
Agree

Glamper 64 I agree. I originally thought it might be a check value. When I turned off city water the water stop coming out overflow. It’s just getting the check value replaced now. Since the freshwater tanks are full I’m running my pump for water. Except when the wife wants to shower.

Thanks everyone
 
Normally the freshwater fill does not allow you to connect a water hose up to it and turn on the spigot with constant water pressure. If this is the case then I can see why the water runs out of the overflow lines under the camper when the tank had gotten filled. I have looked at tons of the Jayco RB TTs and the ones that I have seen do not have a valve that you can switch and automatically fill your freshwater tank.

So there are only two conclusions here. You have an issue with backfilling your tank thru the main feed line to all of your camper waterlines that is connected thru your pump. Or it's possible that you mistook the freshwater hookup.

I've read this entire thread and my head is spinning. :facepalm:

In many of the Jayflight and Jay Feather's I know there are2 separate connections: FRESH WATER FILL & CITY WATER HOOKUP. the city water hookup has a cone screen and a threaded connection. the Fresh water FILL has a pop-off cap and a NON-threaded opening, where you insert a hose extension, in order to fill.

It's pretty difficult to 'mix' them up, unless you a re new to the camper and how each system works....which I do not believe is the case here.

If you use your city water inlet, yet your fresh water tank fills, there's a check valve problem. That's the only answer I come to conclude.
 
JKyle
Thanks. Where is check value. It has to be between where city water and fresh water tank water tie together. All tubing behind walls or cabinets. I believe pump has built in check value. I am replacing pump. Will not know if this fixed problem until I take trailer back out.
 
JKyle
Thanks. Where is check value. It has to be between where city water and fresh water tank water tie together. All tubing behind walls or cabinets. I believe pump has built in check value. I am replacing pump. Will not know if this fixed problem until I take trailer back out.

I'm not an expert at all, but first place I'd suspect is a check valve on the water pump. If you replace the pump and it work okay, then you'll know it was a check valve on the pump. Use your new pump and keep the old one, replace the check valve anyway (good practice) then you'll have a spare water pump and there's nothing wrong about that. :D
 
Yeah my head spinning too with some of those replies, lol. Obviously the pump check valve isn't functioning. If you haven't ran the pump in long time, sometimes exercising the pump will "fix" the check valve.
 
So basically Jerry @#1 had it right :) And I learned there's a check valve in a water pump :) Who would've thought when hooked up to the city water it could leak water thru the water pump into the water tank even though you're not using the water pump...live and learn :) That would explain the 1/3 full tank of water reading I was getting, and drained from my water tank before winterizing even though my trailer has only been hooked up to city water. I'll keep an eye on that and check the newly discovered check valve in the spring :) I'm assuming it's like the check valve behind the screen/washer at the city fill hose connection? Thanks for straightening out this thread, skiprace, and myself :)
 
Had this happen to me before. The check valve in the water pump gets stuck for some reason, sometimes because of junk in the line & sometimes it just gets stuck open! It may clear itself after running the pump for a while or you just need to clean & rebuild the pump. Plenty of YouTube videos on how to do it and the rebuild kits are cheap.
 

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