SOLVED: Fresh Water Tank filling when on City Water

So, I know others have had this happen as I recall threads over the years. Today, in Landmark, Heartland uses the Anderson 4-way valve. It's a water selector of sorts. When City water is connected, you select where you want that water to go by rotating the handle to the various positions. In the City position, it pressurizes the RV water system and life is good.

Lately, I've noticed water coming out of my fresh water tank vent line where on my 2012 Key Largo, is through the I-beam frame rail, near the top, under the entertainment slide area.

Today, I removed the bulkhead wall being the UDC while a couple rally attendees pals assisted with lights, tools, theories and advice.

Removed the input to the water pump, turned the water on at the hydrant and had water pushing through the pump. So, really obvious that this is how the water is getting in.

To double check this, we pulled the line off the 4-way valve that feeds the fresh water tank to fill it from the city water connection. We plugged the water pump to prevent water from going through it and not a drop came out the back of the 4-way valve where we'd removed the fresh water tank fill line. So that sort of trouble-shot part of that valve.

I used a lifeline and texted "a guy" who knows more than we do as to how these coaches are built. He told me this:
- The only check valve Heartland puts in this coach is the one at the water heater
- The Anderson 4-way valve has a built-in check valve

Based on this response, me and the guys are assuming the 4-way valve needs to be replaced.

Anyone have any experience like this and was it the 4-way valve?

Pretty sure what we use is the Anderson 200 RV (link - then scroll down - plastic valve)



If our theory is correct, I guess it's the check valve in the center of the plastic port shown in the image below, that has gone bad.

Re: Fresh Water Tank filling when on City Water

Jim,

I thought I was following the logic all the way up to the conclusion which threw me.

Removed the input to the water pump, turned the water on at the hydrant and had water pushing through the pump. So, really obvious that this is how the water is getting in.

Click to expand...

If I understand this, you disconnected the line from the fresh tank that connects to the pump, turned on city water, and water spilled on the floor as it came out of the pump flowing backwards. If you hadn't disconnected the line, the water would have gone backwards through that line and into the fresh tank, filling and overflowing the tank.

We plugged the water pump to prevent water from going through it and not a drop came out the back of the 4-way valve where we'd removed the fresh water tank fill line.

Click to expand...

The 2nd test seems to confirm that the 4-way valve is not leaking water into the fresh tank fill line.

So if I understand your tests, my conclusion is that the internal check valve in the pump is stuck open. Shurflo will agree that it's time for a new pump. While in there, you can also add an in-line Shurflo check valve as a failsafe.

Re: Fresh Water Tank filling when on City Water

This may illustrate it better than words.

Re: Fresh Water Tank filling when on City Water

Hey Jimbo - I just replaced my pump because it was filling the fresh water tank. It is the 2nd pump I have replaced for that problem (4th pump overall)

The first pump would leak internally into the fresh water tank and I would occasionally hear the pump cycle.
The most recent pump just leaked into the tank, enough so that at the Freindship, PA rally I had to do a "mop up".

Re: Fresh Water Tank filling when on City Water

The pump must have check valves in its outlet in order to pump water. The check valves must prevent backflow or the pump will not move water effectively. You could check the valve module in the pump for debris.
http://www.shurflo.com/files/RV-Product-Data-Sheets/Extreme-Series-Pumps-Accessories/Extreme%20Smart%20Sensor%20pds-5900-0201_0211_.pdf

Re: Fresh Water Tank filling when on City Water

TedS said:

The pump must have check valves in its outlet in order to pump water. The check valves must prevent backflow or the pump will not move water effectively. You could check the valve module in the pump for debris.
http://www.shurflo.com/files/RV-Pro.../Extreme Smart Sensor pds-5900-0201_0211_.pdf

Click to expand...

You should not need check valves. Back flow is stopped at eh valve assembly if it is working correctly. 12 volt water pumps for marine and RV use have been around for a long time, I have never needed back flow preventors or check valves.

The Shurflo you linked to with the PDF is discontinued, no doubt because of the myriad of problems. It is being replaced with a Shurflo # 4048, 4 GPM 55 PSI
The new 4048 seems to be pretty good. good flow and pressure, and the quietest pump I have had yet. The new model uses an internal bypass for the low cycling.

http://www.shurflo.com/files/RV-Product-Data-Sheets/4048-High-Flow-Pump/pds-4048-153-A75.pdf


http://www.shurflo.com/rv-products/...-pumps/4048-high-flow-pump/default.html#tab02

Re: Fresh Water Tank filling when on City Water

UPDATE:

Dan and Duane - you're probably right!

I replaced the Anderson valve and it did not stop the backflow through the pump. So yeah, seems the pump must have a backflow preventer that has failed.

Having service ship a replacement pump to my home. I will replace it next week sometime.

I'll follow-up on this thread when the deed is done

FINAL UPDATE:

I replaced the water pump and the balance has been restored in The Force

But seriously, the water pump "does" contain a built-in check valve and mine was broken. Replacing the pump was the fix and took only a few minutes to do.

jbeletti said:

FINAL UPDATE:

I replaced the water pump and the balance has been restored in The Force

But seriously, the water pump "does" contain a built-in check valve and mine was broken. Replacing the pump was the fix and took only a few minutes to do.

Click to expand...

Jim, I think the pumps are diaphragm pumps and as such do not allow reverse water flow. A check valve of sorts but not really. The rubbers in the pumps can get small particles of debris that cause the diaphragm seal to malfunction.
It may be a design issue or something all together different but Shur flow pumps have been problematic at times. Mine did the same thing very early in life. The stand-by basic 2.8 was sent to me by ShurFlo and has been in place ever since.

Ok, I still am having issues with my pump. What pump are you guys having issues with? Mine is the Shurflo 5.7 and it has started to leak around the head of the pump. Going to give Shurflo a call today.

2psnapod2, the head screws may simply be loose. Tighten them to put the squeeze back on the head seal.

Thanks Ted, but I tried that yesterday. It did reduce the leak but it is still leaking.

Ray - thanks for the clarification. I'll bring my old pump on my next trip and open it up when I get the time. Be nice to have a spare.

Michael - yes, the Extreme 5.7.

All's well that ends well!!!

Even after installing a new pump, it still leaked. Jim, keep an eye on it. I ended up having to put a check valve in line.

Sent from my DROID BIONIC using Tapatalk 2

Michael,

If this one leaks, I think I'll do the same as you and add a physical, external check valve to the output side of the pump.

Thanks for posting this as ours does the same thing. Will have to now find each hose and make sure there all in the right spot.
Pete

wwp,

I don't think you'll need to do any hose tracing. Take a towel with you and pull the utility wall down behind the UDC. The pump is right there. Locate the input of the pump. It's the end with the clear plastic filter bowl. Place the towel under that connector. Using your hand, unscrew the connector on the PEX line that connects to that plastic filter bowl. If the city water is connected and on, and if water is slowly coming out of the input side of the pump onto your towel, your pump is no longer preventing back-flow. As some have said, the cause of the leak could be debris in the diaphragm - inside the pump.

Jim

jbeletti said:

wwp,

I don't think you'll need to do any hose tracing. Take a towel with you and pull the utility wall down behind the UDC. The pump is right there. Locate the input of the pump. It's the end with the clear plastic filter bowl. Place the towel under that connector. Using your hand, unscrew the connector on the PEX line that connects to that plastic filter bowl. If the city water is connected and on, and if water is slowly coming out of the input side of the pump onto your towel, your pump is no longer preventing back-flow. As some have said, the cause of the leak could be debris in the diaphragm - inside the pump.

Jim

Click to expand...

They have mine hooked up backwards. If you have the valve set to city water it fills the tank. Fill the tank is city and so forth.
Pete

This seems like where I need to be , I just got back from a cross the united states trip loved it with the exception of when I connected the city water and used the shower and sinks it used my stored water instead of city water and I noticed water draining off the roof all four corners when city water connected I have a 2012 cyclone and I don't see a valve to switch from city to on board water source ......help I never noticed before because I boondocked it for a year worked fine off self containment .