City water filled fresh water tank/ back flow...

[Romeo84]

Hey guys had my city water connected and everything worked fine. Went swimming and my daughter came back and said the camper has a huge pool around it. Somehow my city water filled the fresh water tank and was pouring out the over flow. 

I double checked everything to make the valve was the right way. How did the fresh water tank fill? Where is the check valve that would prevent that?

Also instead of dumping the water we just switched over to the water pump just to use it. But now water is coming out of the supply connection port.  Any thoughts?

[RIPPPA]

Mine is doing something similar. When hook to city water it won’t fill tank or run inside at faucets. 

[Romeo84]

Yours sounds more like a clog stuck check valve. I had the rubber insert clog the inlet once. Mine is filling when it shouldn't be. Feel like maybe the same check valve wherever it is went bad.

[Bootlegger]

On my RV, I have a manual valve that diverts the water to City or Tank Fill.  If I turn it to City water, the freshwater tank does not fill, and I do not need my water pump.  

[Dr4Film]

Remove the handle and using a pair of pliers rotate the valve 360 degrees a half dozen times in both directions. Reinstall the handle and see if that improves your situation.

 

[Romeo84]

12 minutes ago, Bootlegger said:

On my RV, I have a manual valve that diverts the water to City or Tank Fill.  If I turn it to City water, the freshwater tank does not fill, and I do not need my water pump.  

Exactly but mine filled somehow....

9 minutes ago, Dr4Film said:

Remove the handle and using a pair of pliers rotate the valve 360 degrees a half dozen times in both directions. Reinstall the handle and see if that improves your situation.

 

I will try it. I'm thinking it's not sealing. And some water is leaking by. 

[Bootlegger]

The handles some time strip out and do not turn the valve.  Can you see the valve stem moving?

 

[Bootlegger]

Just now, Bootlegger said:

I can fill my water through the opening on the left or connect a water hose directly below the arrow on the right.  The flow depends on the manual valve next to the arrow on my RV.

[Tom Cherry]

9 minutes ago, Bootlegger said:

I can fill my water through the opening on the left or connect a water hose directly below the arrow on the right.  The flow depends on the manual valve next to the arrow on my RV.

OK, to sort this all out, based some past threads…this is what I think I know….

There are TWO check valves….and don’t ask me to draw a diagram.  When you have an overfill in the fresh tank, one of two things has happened.

Bad “check valve” in the water pump.  There is an in-line or internal check valve in the outlet side of the pump body or impeller.  This prevents city water, under pressure, from flowing backwards into the outlet of the fresh tank.  We have had some failures.

The OTHER cause is the city fill valve has a clog or some trash and is not fully seated into the CITY side or port and is letting some water escape or get out through the Fill port.

The common fix for this is to cycle, sharply, the valve between the city and fill position….and maybe letting it run for a minute or two.  When in the city position, you probably should have a faucet or a line open to dislodge or flush out the ports or the internal passages.  Don’t take a hammer or a rock and beat on the handle to move it further.  There are stops.  You might spray the stem (shaft the nut is on) with a little WD 40, which displaces water and lubricates it.  I had a slow leak, but it took about three different times, driven in between, to get rid of the clog.

BUT, you need to also remove the hose and run the pump on and off a few times, leaving it on.  We have had that….so, it is a matter of shotgunning and flushing both the two position city valve and clearing any debris out of the in-line check in the pump.  Some have installed an additional check valve there.  If you disconnect the INLET side  of the pump, then you have removed it from the circuit.  If you see water coming out of the inlet of the pump….not a drip, odds are….bad or clogged check valve.  Consult the manual from there.  If there is NO flow or leakage…then focus on the fill valve.

The OTHER check valve is suppose to allow you to run your system on fresh without pumping water out of the fill hose.  It is not, I believe, in the circuit that is overfilling.

Note on “Not Able to FILL”.  Been there.  MH had been in storage way longer.  I use a screened washer.  For whatever reason, something was inside the fill valve.  I cycled it several times.  You could barely hear it flowing.  Filled the tank from the outside.  When we came back, say 500 miles and 2 camp sites….I was able, and still am, to now fill the fresh tank as before.  

[Ivan K]

Same year and model as yours but that does not mean much. However, IF your city water valve takes several turns like ours, then it isn't a diventer valve but a usual faucet style valve that only closes holding tank fill line. The only check valve in the house direction is internal to the pump. There should be a check valve preventing flow out to the park hookup when the pump is running but I also installed a manual valve right at a regulator. Here is a look behind the scene on ours. The city valve is top center. Flow towards the house is always open, from factory, so the house faucets still work while filling up without running the pump.

[Romeo84]

3 hours ago, Bootlegger said:

The handles some time strip out and do not turn the valve.  Can you see the valve stem moving?

 

Yes the valve is moving. Wondering if I didn't have it turned or closed fully. Still don't understand the back flow out of the supply inlet when pumpbis running

2 hours ago, Tom Cherry said:

OK, to sort this all out, based some past threads…this is what I think I know….

There are TWO check valves….and don’t ask me to draw a diagram.  When you have an overfill in the fresh tank, one of two things has happened.

Bad “check valve” in the water pump.  There is an in-line or internal check valve in the outlet side of the pump body or impeller.  This prevents city water, under pressure, from flowing backwards into the outlet of the fresh tank.  We have had some failures.

The OTHER cause is the city fill valve has a clog or some trash and is not fully seated into the CITY side or port and is letting some water escape or get out through the Fill port.

The common fix for this is to cycle, sharply, the valve between the city and fill position….and maybe letting it run for a minute or two.  When in the city position, you probably should have a faucet or a line open to dislodge or flush out the ports or the internal passages.  Don’t take a hammer or a rock and beat on the handle to move it further.  There are stops.  You might spray the stem (shaft the nut is on) with a little WD 40, which displaces water and lubricates it.  I had a slow leak, but it took about three different times, driven in between, to get rid of the clog.

BUT, you need to also remove the hose and run the pump on and off a few times, leaving it on.  We have had that….so, it is a matter of shotgunning and flushing both the two position city valve and clearing any debris out of the in-line check in the pump.  Some have installed an additional check valve there.  If you disconnect the INLET side  of the pump, then you have removed it from the circuit.  If you see water coming out of the inlet of the pump….not a drip, odds are….bad or clogged check valve.  Consult the manual from there.  If there is NO flow or leakage…then focus on the fill valve.

The OTHER check valve is suppose to allow you to run your system on fresh without pumping water out of the fill hose.  It is not, I believe, in the circuit that is overfilling.

Note on “Not Able to FILL”.  Been there.  MH had been in storage way longer.  I use a screened washer.  For whatever reason, something was inside the fill valve.  I cycled it several times.  You could barely hear it flowing.  Filled the tank from the outside.  When we came back, say 500 miles and 2 camp sites….I was able, and still am, to now fill the fresh tank as before.  

Well said and written! Had to be bad valve in the pump allowing water to back flow into the tank. Same thing with after the pump runs allowing water to flow out the inlet supply 

[Romeo84]

Ok so the bottom picture is the shut off to the pump. It shouldn't back fill with that closed right?

Also after the pump runs water flows out of the inlet which I would expect to be the remaining water in the lines right? What stop that?

[Ivan K]

Yes, the twist valve by your pump would stop filling the tank if the pump check valve is bad. Of course, you can't use the pump with it closed... About the city hook-up, the piece sticking out is a factory installed restrictor (regarded as a regulator) and check valve. I took it out and replaced with a real regulator with a valve because it took for ever to fill the tank.

[Romeo84]

Well I think that answered that. There it is. That's why is coming out.  Thank you. 

33 minutes ago, Ivan K said:

Yes, the twist valve by your pump would stop filling the tank if the pump check valve is bad. Of course, you can't use the pump with it closed... About the city hook-up, the piece sticking out is a factory installed restrictor (regarded as a regulator) and check valve. I took it out and replaced with a real regulator with a valve because it took for ever to fill the tank.

Did It just unscrew??

[Ivan K]

2 minutes ago, Romeo84 said:

Well I think that answered that. There it is. That's why is coming out.  Thank you. 

Did It just unscrew??

Yes it unscrewed but I had to remove the cover to get to it. It is few inches long.

[Tom Cherry]

1 hour ago, Romeo84 said:

Well I think that answered that. There it is. That's why is coming out.  Thank you. 

Did It just unscrew??

AMEN to that.  Your flow is totally restricted and the pressure is erratic.  Valterra makes one and CW has it on sale.  Had one for 7 years and over 7 months out.

[Bob Jones]

8 hours ago, Romeo84 said:

Hey guys had my city water connected and everything worked fine. Went swimming and my daughter came back and said the camper has a huge pool around it. Somehow my city water filled the fresh water tank and was pouring out the over flow. 

I double checked everything to make the valve was the right way. How did the fresh water tank fill? Where is the check valve that would prevent that?

Also instead of dumping the water we just switched over to the water pump just to use it. But now water is coming out of the supply connection port.  Any thoughts?

There are typically two reasons for the fresh water tank to self-fill. One is the check valve in the water pump is leaking allowing park water to flow past it and into the fresh water tank eventually over-filling it. This is why I suggest always installing an in-line check valve (not from an RV store). You can get them on Amazon. Of you do this, get a 3/4" valve and use adapters to bring it down to 1/2". This way it will not be a flow restriction. 

The second place they leak is the City-Water valve. This is typically a ball valve, often hard to replace. Debris can be stuck in it. I suggest removing the handle and flattening the flanges that prevent it from being turned 360 degrees. Then you can turn it around while under park pressure and hopefully it will clear up. In my specific case, I replaced it with a new one and it still leaked. Turns out, if I turn it to the 2 o'clock position it then seals. 

With respect to the water pressure going back out the city port, this is because the factory check valve, typically next to the City/Water valve is leaking. This too can be difficult to replace. 

To address your issue I suggest you do two things. Buy TWO 3/4" check valves, put one in discharge line from the water pump and put the other on the inlet side of the City/Water valve (where you attach the hose). This will cover both of your problems. Hopefully you won't need to replace the City/Water valve as they can be a pain if they have PEX lines and copper crimp rings going to them, but it's dependant on the design of your specific unit. 

PS, I have now put wire mesh hose washers in the city water feed line and also the black tank flushing line in an effort to prevent the odd tiny rock or whatever from going through the plumbing.  Hope this helps.

[Romeo84]

On 7/7/2022 at 9:59 PM, Bob Jones said:

There are typically two reasons for the fresh water tank to self-fill. One is the check valve in the water pump is leaking allowing park water to flow past it and into the fresh water tank eventually over-filling it. This is why I suggest always installing an in-line check valve (not from an RV store). You can get them on Amazon. Of you do this, get a 3/4" valve and use adapters to bring it down to 1/2". This way it will not be a flow restriction. 

The second place they leak is the City-Water valve. This is typically a ball valve, often hard to replace. Debris can be stuck in it. I suggest removing the handle and flattening the flanges that prevent it from being turned 360 degrees. Then you can turn it around while under park pressure and hopefully it will clear up. In my specific case, I replaced it with a new one and it still leaked. Turns out, if I turn it to the 2 o'clock position it then seals. 

With respect to the water pressure going back out the city port, this is because the factory check valve, typically next to the City/Water valve is leaking. This too can be difficult to replace. 

To address your issue I suggest you do two things. Buy TWO 3/4" check valves, put one in discharge line from the water pump and put the other on the inlet side of the City/Water valve (where you attach the hose). This will cover both of your problems. Hopefully you won't need to replace the City/Water valve as they can be a pain if they have PEX lines and copper crimp rings going to them, but it's dependant on the design of your specific unit. 

PS, I have now put wire mesh hose washers in the city water feed line and also the black tank flushing line in an effort to prevent the odd tiny rock or whatever from going through the plumbing.  Hope this helps.

Well written! Thanks. Actually did what you said probably while you were typing it. Thanks again!

[Bob Jones]

2 hours ago, Romeo84 said:

Well written! Thanks. Actually did what you said probably while you were typing it. Thanks again!

Yeah, I was a bit late on my reply! I meant to get at it earlier but I was busy fixing the water system on my Dad's unit. It's new and I had to re-route all the electrical/water/propane lines going into the slideout. I answer anyway, even if late, for the sake of others referencing this thread in the future even if I missed your boat 🙂