Fresh water tank filling from city water.

[Ron045]

Water is overflowing from the fresh water tank inlet. We never use the fresh water tank and always connect to city water.

A camp neighbor believes there is a bad check valve somewhere.

Thoughts?
2017 Flagstaff 23IKSS.
Thanks.
Ron

[NavyLCDR]

Well.....it's been about 4 days since this was posted again! That's a pretty long time between these posts, which run between 4-6 times per month. There is a check valve inside your water pump. This check valve is supposed to keep water from flowing from the city water connection backwards through your water pump into the fresh water tank. So, to attempt to clear debris and reseat that check valve, you want to fill your fresh water tank between 1/3 and 2/3 full. Disconnect city water (or at least turn off the water supply). Turn on your water pump. Open a faucet and leave it open. Let the water pump run for a few seconds then shut it off. Turn the water pump back on, let it run for a few seconds, shut it off. Turn the water pump back on and close the faucet. Let the water pump turn itself off. Now reconnect to city water and monitor fresh water tank level.

If fresh water continues to fill, you will need to either add another external check valve to the inlet of the water pump or replace the water pump. In the meantime, if your freshwater tank continues to fill you can just simply disconnect from city water. Whenever you need to use water turn your pump on and use water from the fresh water tank. When you are done using water turn your pump back off. You can do this until you can add an external check valve or replace the water pump (or use a rebuild kit to rebuild the water pump). The reason you don't want to leave the water pump turned on in this condition is because the pressure on the discharge side of the pump will bleed off backwards through the leaking check valve and the pump will continue to cycle on and off.

[Keithe]

I’ve had this same problem as many others on this forum. There is a valve that is suppose to keep city water from flowing back into your water tank and it can sometimes get stuck open. What I do is shut of the city water and use the water in my storage tank. After I’ve used about half a tank of water, I turn back on the city water and the valve seem to get reseated. I have to do this about three times a year.

[Ron045]

Sorry LCDR... I probably should have searched before I typed.

It was night and raining and my camp neighbor knocked on my door to tell me about the water.

So I was trying to ID the problem in less than ideal conditions.

In and unrelated matter DW was also complaining about no hot water and my son ran out of data and forgot his user p/w. Haha... Last on the priority list buddy.

Hot water first. Happy Wife... I figured when doing that, you kind folks would supply me with good info on this problem. Which you did.

We ran the pump from the full fresh tank all last night. We nearly drained it. Just hooked up to city this AM to see if that cleared the problem.

The pump did want to cycle every so often when there was no call for water. We turned it off when we went to sleep.

More to come.
Thanks
Ron

[Ron045]

Hooray!!! I guess running all that water through the pump cleared the check valve. No more leaks or overflow.

Thanks again.
Ron

[NavyLCDR]

Glad it sorted itself out for you!

[Ron045]

Well the problem resurfaced. Went to a local RV store to buy a new check valve. It's in the pump. A new pump was $120. But the guy actually told me I could buy the same pump on Amazon for $60. Then he sold me a $2 cap and showed me how to cap the line and bypass the pump so city water will work for the weekend until we get home.

With that great service we had no problem buying other things we wanted/needed at the store.

Water works and no leaks or overflows.
Ron

[Gumpster808]

Glad you got it figured out. Nice of them to tell you that it was less expensive somewhere else.

[Sbosserman]

Here’s how to stop that. Save this to you phone like I did. I’ve had this happen a couple of times over the years and I got this off this forum, it’s has worked for me.

To stop water pump from slowly filling fresh water tank while connected to city water:

1. Shut off city water
2. Open a faucet until the water stops running
3. Shut off faucet
4. Turn on water pump, open faucet and run water for a minute
5. Shut off faucet
6. When pump stops running, turn off pump
7. Turn on city water
8. This procedure will receipt the water pump backflow valve. Remember: do not run water pump with city water on.


Thanks to whoever originally posted this procedure, it works!

[Buckeye Dad]

Originally Posted by Sbosserman

Here’s how to stop that. Save this to you phone like I did. I’ve had this happen a couple of times over the years and I got this off this forum, it’s has worked for me.

To stop water pump from slowly filling fresh water tank while connected to city water:

1. Shut off city water
2. Open a faucet until the water stops running
3. Shut off faucet
4. Turn on water pump, open faucet and run water for a minute
5. Shut off faucet
6. When pump stops running, turn off pump
7. Turn on city water
8. This procedure will receipt the water pump backflow valve. Remember: do not run water pump with city water on.


Thanks to whoever originally posted this procedure, it works!

What happens if you accidentally run the water pump with the city water turned on? How long would it take to cause harm to the system?

[pgandw]

Originally Posted by Buckeye Dad

What happens if you accidentally run the water pump with the city water turned on? How long would it take to cause harm to the system?

It's going to depend on the situation. If city water pressure is greater than pump water pressure shutoff AND the backflow check valve stays in place, nothing bad happens.

If city water pressure is less than pump water pressure - even momentarily - then the backflow check valve opens. If pump pressure drops below its low limit, the pump turns on until the high limit is again reached. Backflow check valve may or may not reseat when pump turns off, especially if city water is confusing RV water pressure.

If backflow check valve doesn't seat, the pressure pushes water into the water tank. Does the overflow/vent vent enough air/water quickly enough to stop tank from being pressurized? There have been numerous reports where the tank bulges under the pressure. How much of a bulge before things break?

Fred W
2019 Flagstaff T21TBHW A-frame

[whatsupchuck]

I understand the why and how with the pump. Water has filled my belly pan several times before starting the search for the source. Can, or has, anyone seen the location of the overflow for 2017 Rockwood Windjammer tanks?

I've finally reached the point where I filled the fresh tank, city water not attached and am waiting to see if the tank/fittings really leak or is it overflow caused by the pump check valve. I can see all the tank fittings on the driver side of the tank but wonder where the overflow would be other than the air vent near the fill line from the exterior.

Another question would be can an external check valve be added after the output of the pump or not?

No hurry as 12 year old duramax just started leaking coolant. Not getting attention I guess.

[bikendan]

Originally Posted by whatsupchuck

Can, or has, anyone seen the location of the overflow for 2017 Rockwood Windjammer tanks?

You should be asking this question, in the Rockwood sub-forum, not the General Tech and Repair section since it's a model-specific question.

[whatsupchuck]

Anyone with a Sureflow 4008 has this problem.

[Capacitor]

L https://www.amazon.com/SHURFLO-340-0...7589526&sr=8-3