City water backing up into fresh water tank.

[CJnDD]

Has anyone experienced city water backing up into fresh water tank? This has happened to us twice. The first time was over night and woke up to wet carpet in bedroom. This past weekend it happened again, but we caught it in time.

Service department did not know what the cause could be from both times.

Any one else have this problem?

Our unit is a 2012 Forester.

[Papa GLS]

Yes. Replaced water pump (under warranty) & it corrected problem.

[Ford Idaho]

Is the FW tank over flow tube capped or plugged?

Could be the FW check valve.

[bubbles]

Your water pump is allowing a backflow into the tank. The head of the pump is where the check valve is located. Sometimes one can shut off shore water and turn on the pump on and off several times with a faucet open to try and reset the baffle inside the pump. If that doesn't work and you have the winterization input hose with a selector valve to pump antifreeze with the pump and the antifreeze hose has a cap on it you could select winterization mode for the pump and the water will not backfill into your tank. It will be routed to the capped winterization hose. This should suffice till you can get a new pump or repair the one you have.

[CJnDD]

Thank you all....will check out your suggestions.

[elundquist]

There should be a check valve at the water pump that prevents water from push backwards through the pump to the FW tank.

It sounds like your check valve is stuck or blown out and needs to be replaced.


Erik Lundquist
iPhone 6S using Tapatalk

[Mr. Dan]

Originally Posted by CJnDD

The first time was over night and woke up to wet carpet in bedroom.

How did this happen? Is your FW tank under your bed? I'm not familiar with your unit.

[CJnDD]

Yes FW tank is under bed.
I brought the unit in the first time and service department could not find anything wrong. Yesterday I went in, without the unit, and told them the same thing happened. They still say they have never run across this before.

The pump is in a very thight place that is extremely hard to get to. Impossible to get to the valve in it's location. I will have to bring the unit back to them.

[bubbles]

When you take it back have them come to this site and run a search for "water back flowing into fresh water tank". Should enlighten them.

[SpringerPop]

Your service department's techs are either stupid, or they're lying to you about "never seen THAT before".

Not rocket science.........

Pop

[CJnDD]

Originally Posted by bubbles

When you take it back have them come to this site and run a search for "water back flowing into fresh water tank". Should enlighten them.

Thanks bubbles...did that search will show the service department.

All of you are very helpful, thank you.

SpringerPop... You could be correct!

[Pilot172]

I had the same problem a month back. I recycled the pump by turning it on and off a couple of times and didn't have a problem during the last two trips. Used the city water without it back filling the fresh water tank. Found the info on this site (as usual) and it worked great.

Good luck!

[CJnDD]

Thanks Pilot172....I will give that a try before taking the unit to service department.

[clicker1944]

Originally Posted by Papa GLS

Yes. Replaced water pump (under warranty) & it corrected problem.

X2...fixed too.

[clicker1944]

Originally Posted by CJnDD

Yes FW tank is under bed.
I brought the unit in the first time and service department could not find anything wrong. Yesterday I went in, without the unit, and told them the same thing happened. They still say they have never run across this before.

The pump is in a very thight place that is extremely hard to get to. Impossible to get to the valve in it's location. I will have to bring the unit back to them.

I would at this point lost all confidence in that service dept. They are either lying or totally incompetent.

[Mr. Dan]

Your service techs may not be lying. The possibility exists that they were laying brick or working in a nursing home last week!

[JLeising]

Some thoughts on this issue - FWIW -
On our Solera - and, I suspect, on most RVs - the internal water filter is plumbed AFTER the water pump - therefore after the check valve which prevents city water from flowing into the fresh water tank. As such, any sand, dirt or other material in the incoming water can enter the check valve and cause it to leak. I believe using a filter at the hose spigot can significantly reduce the incidence of this problem by keeping such crud out of the check valve.

[Grumpy Guy]

This may be a dumb question but does everyone use a inline pressure regulator on the the city water feed hose and/ or could it be allowing over pressure in the system that allows water to feed into other areas?

[dahagen]

My son runs an RV repair shop near Denver and when I had the problem he said it is a common problem. I discovered it when my fresh water tank overflow had water coming out of it. Had my water pump replaced under warranty.

[elchilero53]

Originally Posted by JLeising

Some thoughts on this issue - FWIW -
On our Solera - and, I suspect, on most RVs - the internal water filter is plumbed AFTER the water pump - therefore after the check valve which prevents city water from flowing into the fresh water tank. As such, any sand, dirt or other material in the incoming water can enter the check valve and cause it to leak. I believe using a filter at the hose spigot can significantly reduce the incidence of this problem by keeping such crud out of the check valve.

I believe that you have hit on something here. Ours is in the shop for warranty work and I told them the same thing about back flow into the FW tank. They will replace the pump but I think that they should probably re-plumb the filter as well. Sounds like a poorly thought out configuration.