Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 06, 2025 ...

Filling fresh water tank

July 06, 2025, 06:40:23 pm

I tried to go on city water and it filled the fresh water tank and then overfilled it. I can only use the pump while camping which works fine. Why cant I connect city water to the coach and use that while in an rv park without water running out of the overflow?
Did my fill valve under the sink fail or the connection for the city water or is it designed to just fill and then pump out of the tank with my pump?
Thanks

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Re: Filling fresh water tank

Reply #1 – July 06, 2025, 06:43:04 pm

Could be the fill valve not sealing.

Also, could be the check valve in the pump has failed allowing water to "backfeed" the tank.

Either will allow city water to fill/over-fill the tank.

Do you have a pressure reducer in thehose from city water?

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Re: Filling fresh water tank

Reply #2 – July 06, 2025, 07:19:31 pm

If everything is working properly in your coach, you should be able to connect to city water and use everything in the coach water system, without worrying about the fresh water tank over filling.  So, as Brett has mentioned, something is NOT working properly.

However, even if everything in your coach IS working properly, many Forum members will recommend that you DO NOT make a habit of leaving your coach connected to city water pressure.  They will advise that you fill your tank from the city connection, then shut off the city water pressure and operate using your water tank and water pump.

Why?  Because if you have been around RVs of any kind for long enough, you will have heard the "flooded" stories.  Campers come back to the RV after a day outing, open the door, and water pours out.  Or they wake up in the middle of the night, get out of bed, and step into several inches of water around the bed.  How does this happen?  The RV is connected to city water pressure, a pipe breaks, and water flows continuously out the broken pipe until somebody shuts off the city water connection.

IMO, you should fix whatever is not working properly.  Then you should consider using the water pump, rather than city water pressure, even when you are in a full hookup campground.  We have always done this, and in addition made it a rule to only turn on the water pump when actually using water.  When done using water, we turn the pump off.  You will be surprised how quickly you can adopt this habit and it becomes second nature.

Of course, this is only a suggestion.  It's your coach, and you can do whatever makes you happy.

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Re: Filling fresh water tank

Reply #3 – July 06, 2025, 11:20:52 pm

Heed those words from Brett & Chuck & Janine. It has happened twice to me. Fortunately nothing inside just an over flow. So I normally fill the tank to about 3/4 and live off the pump. I never leave the campsite without turning off the house pump and making sure the city water is off.

Of course I have on occasion used city water when doing an overnight as I don't want to haul around a ton of water. I normally only have about 1/4 or less. Just enough to have a quick Navy shower and do dishes. But even doing this I take precautions. I make sure the fill valve is closed with no city water pressure to hold it open. Then take a shower(s) then city water is turned off for the night. 

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Re: Filling fresh water tank

Reply #4 – July 07, 2025, 09:26:00 am

If you fill your water tank and live off the pump, when you are almost out of fresh water, it is time to empty your black and grey.  Great schedule to adopt. Keeps things moving and always a good idea to have your eye on what it going on.  We did have a check valve that got some grit stuck, which kept it open and water back flowed out.  We went nuts trying to figure out (1) What the issue is ... (2) Where is the check valve??? (Even James Triana couldn't help us!) ... (3) HOW to get to the insides to look/fix the issue.  We were in Leadville, CO ... gasping for air ... hot spell  ... mosquitos the size of hummingbirds eating us alive while we sweated and worked. Good times ... good times ....

After fixing that issue, we always used a 2 stage water filter when filling the tank. No more sediment issues.

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Re: Filling fresh water tank

Reply #5 – July 07, 2025, 09:55:50 am

We have same year/model. I replaced the ball valve under the bathroom sink and all was solved for many years. Just developed the problem of water bypassing the pump check valve. Since I needed another shutoff valve to eliminate requiring a tank dump to replace the pump, I just put a ball valve between the pump and the tanks supply. (Yes, lazy). Voilá I no longer have the tank "mystery filling" problem. I just have to remember to operate the valve in front of the pump when we are not hooked to shore water.

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