fresh water Tank filling on its own

[k9jkfham]

2014 Vista 35F....Problem Just Started....Hooked up fresh water to Park water. Water goes thru 2 clearsource portable filters into coach.. Water pressure is restricted to no more than 50 PSI. Noticed water coming from fresh water over flo. Drained the fresh water tank to 1/3 full. The tank continued to fill very slow. Shut off park water and the filling of fresh water tank stopped, I have moved the fill control knob back and forth many times and still no luck.

Looking for suggestions where to start looking. Could it be the control valve not completely stopping the fresh water fill?

Any ideas or suggestions welcome. We are on the road and hopefully we can use the water pump until we get home in 45 days.

[Airboss68]

There are 2 locations to consider.
#1 your freshwater pump has an internal check valve that if not working can let water back flow from the city water system to the fresh tank this can be a faulty check valve, or a piece of debris stuck in the valve.

#2 Is your water control valve. Same issues defective or stuck debris.

1st step I would consider is adding an external check valve on the inlet side of your pump. If that doesn't fix it then the problem is at your freshwater inlet/fill valve.

We have had 4 RV's and had this problem in all of them. In three it was the check valve and one the fresh water fill valve.

[l1v3fr33ord1]

Ken-

This symptom has two common causes:

1) The city/tank valve leaks by, or
2) The water pump internal check valve is stuck open

If you have easy access to the water pump, you can put a new check valve at the pump outlet. If that does not solve the problem, then it's likely the city/tank valve is at fault.

My coach had a shutoff valve in the outlet from the fresh water tank to the water pump inlet. Closing that valve was the equivalent of installing a check valve at the pump outlet.

I see "Airboss68" posted the same info while I was typing this post.

[k9jkfham]

The water is still passing somehow into the fresh water tank. I have spare water pump but it is at home and it will be the end Of September until we get home. What size hose is used in the system. I will try the external check valve.

[l1v3fr33ord1]

Ken-

The fittings on the pump are 1/2-inch National Pipe Thread (NPT). This is a common size for house plumbing fittings and supply hoses.

The easiest solution may be to attach the check valve directly to the pump outlet. Some water pump locations make this impractical. If so, use flexible supply hoses to insert the check valve. Avoid permanent modifications until you are sure the check valve is needed.

[k9jkfham]

I want to verify my thoughts. City Water turned off so no new water is coming into the MH.
We are using on board fresh water. When empty refilling with City Water.
The water pump still surges when we are not using water and the pump is on.

This leads me to believe that the surge issue is from the water pump. Is that a valid statement?

Would his cause the fresh water tank to slowly fill up since no city water is coming into the coach?

I did find my spare water pump (Shurflo 4008-101-F65) Where can I purchase repair kit for this pump?

[Morich]

Okay, I did a look at how it can do this and ist is a semi-common thing!
If we look at the interactive parts drawings here, we can sort the route.
https://catalog3d.winnebagoind.com/menu/Parts.htm

When it works right and we have water coming in the inlet,goes both left and right. if the selector knob is turned to normal use, the water is cut off in that direction, so goes to left and the rest of the RV.
When the selector is to fill the tank, water flows through and into the tank.
Normal operation also lets pressure goes down and around to the pump but there is a check valve there that should stop the flow backwards through the pump!



On the snip below, the green line shows where water should go from the hose into the line but cut off from the tank and also cut off at the pump, so it flows into the RV only.
BUT if the selector valve leaks it can go to the tank and slowly fill it. OR the more common item is the little flap of rubber that acts as a check valve at the water pump. It get brittle or a bit or rubber gets nicked and water slowly filters past it, through the pump backwards and up into the tank!

My first bet would be that the check valve is bad as the plastic selector valve tends to pretty much crumble up when it gets to that point, while the little rubber flap is more likely to just get wimpey and not close really well.

Familiar with bathroom stool flaps which get brittle and let water run into the stool? Pretty much the same idea but smaller!

So you can put a new check valve inline at the pump output and not worrry changing the first one, just let it leak through and the second stop the flow OR change the built in one.
I do the one which requires less stress to get to things like remove the pump??

The water pump comming on/surging can be simple and no big thing or show you have a leak?
IT means the pressure it has built up and shut down is being lost and it thinks it needs to rebuild that pressure.
One place pressure can be lost is a tiny little thing that passes as a check valve. If you look directly into the fitting where the hose connects, you may see a lttle plastic flap pressed against the fitting by a small spring. That is the "check valve" to keep water from the tank going out the inlet when no hose is connected. Touch it gently with a pencil to see how little pressure it has to imagine why it may leak a little air out!! Gently because they tend to get brittle and break easy!!

[Morich]

Note? If you feel the tiny check is leaking, one way to cure it without much trouble is to get a nylon plug to screw in the inlet port to actually seal it well when not connected to a hose?

The other and far worse problem can be a small leak, hidden away somewhere that you don't see it!
BAH! Hope for better luck! Maybe it's only the stool flap leaking through!

[creativepart]

This problem is super common and the fix is usually simple.

First, turn off the City water hose bib and live off of fresh water in your now full tank.

Here's why this usually happens. A tiny spec of sand or dirt gets in the small check valve built into the pump and so water flows past the small piece of dirt.

Usually, running a full tank of fresh water through the pump without any City water connected will dislodge that piece of dirt. Problem solved.

If it doesn't solve the problem, there are two choices - both mentioned above. The first option is to purchase a $15 check valve rebuild kit -- which is a couple of simple parts and rebuild the valve. You don't even have to remove the pump to do this chore. OR, you can buy a replacement check valve for about double the price of the rebuild kit.

The other definitive fix is to add an external check valve - also mentioned above. You can get this for very little money on Amazon or even at a Home Depot. This is a good long term fix. I've seen folks say the new check valve goes on the inlet side of the pump (left side where the strainer is) and others say it goes on the outlet side of the pump. I see the logic in each but I think the outlet side is maybe the most logical. Heck, you could put one each on each side too.

Many, most, all? of us have had this issue. I know for me the first option of turning off the city water and living off of the fresh tank has worked about 80% of the time for me.

I have rebuilt the check valve once - it is a 10 min task at most. Just a spring and a diaphragm were needed to rebuild the valve.

It is true that sometimes it's the diverter behind the City/Fresh fill valve - but thankfully that's vastly less common and not likely to be the issue.

[creativepart]

Originally Posted by k9jkfham

The water pump still surges when we are not using water and the pump is on.

This leads me to believe that the surge issue is from the water pump. Is that a valid statement?

By "surges" do you mean that every once and while it runs for a second or less occasionally when no water outlet is turned on?

That could be a leak somewhere in your system, but it is likely that you need to adjust the pressure valve. This is done at the pump with an allen key. Plenty of videos on YouTube on how to do this. Be a bit careful, if you do too much this can effect with pump turning on and turning off in use. But don't worry, just take it very slow.

Originally Posted by k9jkfham

Would his cause the fresh water tank to slowly fill up since no city water is coming into the coach?

How? You can't add water to the fresh tank unless you have the City water hose putting water into the system (or the gravity feed).

Originally Posted by k9jkfham

I did find my spare water pump (Shurflo 4008-101-F65) Where can I purchase repair kit for this pump?

The Shurflo 4008 is the most popular water pump used in RVs. You can get total rebuild and parts kits on Amazon.

Generally, the pump doesn't need replaced or even rebuilt just properly adjusted. However, you can purchase an entire new front half - the pump head for $30 and replace it on your existing pump motor in just minutes - I think it's like 4-screws and you're done. You not only get a new pump mechanism, but a new check valve and a factory set Pressure Valve all in one part:

https://www.amazon.com/SHURFLO-94-80.../dp/B00SQ4F4V2

[Morich]

The thought of which side to put a check valve has prompted me to do some thinking and it may have let me wake up a few dead brain cells!
Let's do a little looking at the idea of which side to put any new added check valve?

This sketch is pretty "sketchy" but maybe will do.



The pump is turned on/off by the pressure setting sensing the pressure on the output side of the pump. Just for handy figures, can we say it turns on at 15 PSI and off when it gets pressure up to 20PSI and that is on the output side where we use the water at faucets, etc.

If we add a check valve to the left or output side of the existing pressure sensing and leaking check valve, I see a potential problem!
If we have a good check valve stopping water from running back from the pipes and faucets, but leave a leaking check valve to let water go back to the tank, don't we have a situation where the pressure setting is going to drop below 15 PSI and turn the pump on again?

I suggest that the new check valve needs to be on the input side to hold that pressure and keep the pump from turning on!

Right side in this drawing but between the tank and pump on the RV!

[creativepart]

To double check, I just did a Google search for adding an external check valve to the water pump and guess what I found? Opinions were equally divided about what side was correct.

For every one that said put it definitely on the input side I found just as many that said NO, put it on the output side. I found one person that tried adding the check valve to one side and then he moved it to other side. He said it worked fine on either side. Oh, well.

I was hoping to find a definitive answer but found only more armchair experts like me. That's why when I suggest putting an external check valve in the water system I try to always add that there is a debate about what side it should go on.

Also, I don't think your diagram applies to my plumbing layout.

[geneorpana]

Take the suction hose off of your pump. It will probably have water coming out which is not supposed to happen if the pump check valve is working. So, rap on the pump a few times with a small mallet or vise grips (like I did) and the water should stop. If it doesn’t, shut off the shore water and dump the system pressure. Rap on the pump a couple of more times and then reconnect the suction hose and turn the pump on and run some water thru it. Turn the shore water back on and disconnect the suction hose again and there should be no water coming out of the pump. Most times, pumps internal valve gets cocked or a bit of debris gets stuck in it. Worst case, replace the pump or add another check valve on the suction side of the pump. Cheers

[jerichorick]

Originally Posted by k9jkfham

2014 Vista 35F....Problem Just Started....Hooked up fresh water to Park water. Water goes thru 2 clearsource portable filters into coach.. Water pressure is restricted to no more than 50 PSI. Noticed water coming from fresh water over flo. Drained the fresh water tank to 1/3 full. The tank continued to fill very slow. Shut off park water and the filling of fresh water tank stopped, I have moved the fill control knob back and forth many times and still no luck.

Looking for suggestions where to start looking. Could it be the control valve not completely stopping the fresh water fill?

Any ideas or suggestions welcome. We are on the road and hopefully we can use the water pump until we get home in 45 days.

I have a suggestion outside that of the above posts. Shut your water off. If you pull the knob off the city/fill valve you should see a knurled nut. Do what you need to to gain access to this nut. Carefully remove the nut and gently pull the cartage out. If any of the plastic fingers are broken or missing you have found your problem. I replaced my valve with a brass ball valve. Works fine.
In your manual, if written as mine is, the city fill instruction state NOT to turn the fill valve with city water on. The valve is too fragile to be operated under the pressure from the city water.
I hope I have been helpful. Happy trails.
Rick

[JR314]

Originally Posted by k9jkfham

I want to verify my thoughts. City Water turned off so no new water is coming into the MH.
We are using on board fresh water. When empty refilling with City Water.
The water pump still surges when we are not using water and the pump is on.

This leads me to believe that the surge issue is from the water pump. Is that a valid statement?

Would his cause the fresh water tank to slowly fill up since no city water is coming into the coach?

I did find my spare water pump (Shurflo 4008-101-F65) Where can I purchase repair kit for this pump?

This could be the pump check valve, but it could also be the City Water/Tank Fill valve as mentioned in the earlier responses. I had the same problem and it was my City Water/Tank Fill valve causing the issue. That valve gets bad and it won't seal properly which causes city water to leak into the tank fill side of the valve. Because the valve leaks, it won't hold pressure in the line, which is why your pump is activating even when not in use. It is turning on to maintain pressure much like it would when you turn on the faucet and there is a demand for water. I was able to buy a replacement valve and then remove the guts from it and put it in the old valve body. Many replace the whole valve with a new brass valve, but mine was hard to access and I didn't want to spend the time or energy when it happened.

[bobby5832708]

I finally fixed my 2017 29VE that had this same issue. I had to replace the quarter turn fill valve.

My 29ve had the tank-filling issue for about a year. It wasn't a big deal as the tank gained roughly 10 gallons a day when the rv was hooked up to city water and when it was full the excess ran out the vent. Sometimes when camping I remembered to shut off the city water, sometimes I didn't. A couple of months ago I decided to fix the problem.

The valve is a pex/pex (both connections pex), not a pex/threaded like you find at the big box stores. I ordered a 10-pack of pex/pex valves from an eBay seller so I've now got a lifetime supply of these valves for when this happens again.

From what I remember, it was a fairly easy fix once I got access. I disconnected the water inlet, wires to the light and the outdoor kitchen pump switch, removed the valve handles and mounting bolts from all the quarter-turn valves, and removed the metal panel. That gave me enough room to pop the pex collars off and crimp on a new valve. There are lots of pex crimps and tees and several valves in the plumbing behind the control panel so you have to replace the tank fill valve with one that is of the same configuration or else you have got a much more difficult repiping job to do.

If things like this are all that goes wrong on the 29VE then I'm going to be a very happy owner. I don't mind doing minor repairs like this, it's an RV so I know things are going to break. I've heard all the RV horror stories and so far I've had pretty good luck with my Winnebago.

Just what I did, your mileage may vary, etc. etc.

[Morich]

Originally Posted by bobby5832708

I finally fixed my 2017 29VE that had this same issue. I had to replace the quarter turn fill valve.

My 29ve had the tank-filling issue for about a year. It wasn't a big deal as the tank gained roughly 10 gallons a day when the rv was hooked up to city water and when it was full the excess ran out the vent. Sometimes when camping I remembered to shut off the city water, sometimes I didn't. A couple of months ago I decided to fix the problem.

The valve is a pex/pex (both connections pex), not a pex/threaded like you find at the big box stores. I ordered a 10-pack of pex/pex valves from an eBay seller so I've now got a lifetime supply of these valves for when this happens again.

From what I remember, it was a fairly easy fix once I got access. I disconnected the water inlet, wires to the light and the outdoor kitchen pump switch, removed the valve handles and mounting bolts from all the quarter-turn valves, and removed the metal panel. That gave me enough room to pop the pex collars off and crimp on a new valve. There are lots of pex crimps and tees and several valves in the plumbing behind the control panel so you have to replace the tank fill valve with one that is of the same configuration or else you have got a much more difficult repiping job to do.

If things like this are all that goes wrong on the 29VE then I'm going to be a very happy owner. I don't mind doing minor repairs like this, it's an RV so I know things are going to break. I've heard all the RV horror stories and so far I've had pretty good luck with my Winnebago.

Just what I did, your mileage may vary, etc. etc.

Kind of like the rest of life, isn't it? We do the best we can, repair what needs it and move along!

[k9jkfham]

I purchased a new valve. Part numbers changed. The one on the motorhome is riveted to the panel to prevent the valve from moving. The new replacement valve has no place to secure the valve to the panel.

Has anyone installed this new valve without screws or rivets?

[jerichorick]

Originally Posted by k9jkfham

I purchased a new valve. Part numbers changed. The one on the motorhome is riveted to the panel to prevent the valve from moving. The new replacement valve has no place to secure the valve to the panel.

Has anyone installed this new valve without screws or rivets?

This style clip can be used with a machine screw and nut: https://www.amazon.com/MJIYA-Fastene...%2C153&sr=8-14
If you bought the plastic valve be certain not to have city water pressure on it when you turn it. I might fail again. This is why many of us have gone to the brass ball valve.