Fresh water leaking into bottom under floor

[Sujane80]

Recently I have had dripping from the bottom of my 16 foot northern lite while on city water. I thought it was grey water tank but rv repair guts tell me there is a leak somewhere in the fresh water system into the well between the floor and the fiberglass. Nothing shows up where it might be seen under the sinks. So it drips out places but could be "travelling". They say that they would have to cut a hatch into the bottom to find the leak.

When I use the tank and pump the leaking stops or at least is very minimal so I am doing that all the time instead of city water.

My concerns are: the pump cycles briefly every minute or so when not running water. Thus means there is a leak somewhere? Also the moisture collected between the floor and the fiberglass - will that dry up or should I worry about mold and mildew? Especially since there still seems to be a tiny leak somewhere. Anyone else had an issue like this?

[Civilguy]

Susan,

Yes, it sounds like the water is going somewhere and that would pose a very high risk of creating problems.

You might try gently dragging a dry paper towel everyplace that you can reach that might have a waterline or any water collecting. It will wick up any moisture and might help you locate the problem without cutting holes in the trailer.

[tractors1]

I would check with the manufacturer regarding the pipe routing. It would be an incredibly poor design if there were fittings which could not be accessed without cutting holes.

Maybe you have a split/cracked hose due to freezing, or the leak is at the city water inlet connection? Do you use a regulator when connected to city water?

I would think you could loosen both ends of the piping run and fish a new pipe through the space using the old one to pull it through. If not can you pull the city water inlet assembly and see inside then?

[Kevin A]

On our 1988 Bigfoot, we've had two old pipe junctions work loose, causing the same symptoms. I was able to get at our problem under the bed, which has an access door to the furnace and plumbing area. I bought new push-on connectors and installed them to replace the old crimped elbows and T. Since the water pump is cycling every few seconds and you have a leak under pressure with both city and tank water. I would look for a leaking pipe or connection. It must be just a slow drip or the pump would run all the time.

[trentn]

My 2000 SD has a small drain hose (about 1/4” ID maybe 1/2” OD) leading to an outside spigot. If your’s has the drain spigot, check inside the baggage door to see that it hasn’t worked loose and laying on the floor.

I had to push my drain hose back on the spigot and clamp it.

[Buggeee]

I will post here in case someone stumbles on your thread in a search for pump cycling every so often. Definitely a leak in the pipes will cause this, and you have water leaking so I fully agree with the other posters' assessments. If someone does not have a leak anywhere and the pump is cycling every so often anyway, then the pump's internal check valve is worn and needs replacing. I had this happen and got a replacement check valve real cheap on E-bay or Amazon and its easy to replace in the pump. Comes with instructions.

Good luck on the hunt for your leak!