Fresh water being used while using full hookup

[xo1rider]

I'm trying to figure out where my fresh water is going. Starting out with a full tank then hooking up to city water. Water pump never turned on but then I check the next day or two and find the fresh water down 1/3 to 1/2. No external leak and I verified by filling the water again to make sure it was not just the gauge.

The reason I've been traveling with full or almost full fresh water is the outside air temp. at times has been below freezing and I sometime have to disconnect from city water at night.

Thanks,

[Wazbro]

The only thing I can think of is that somehow you are getting a venturi effect. The same way some well pumps work where water is pumped down a 1" pipe to a Y to pull water up a 1.5" pipe. (not sure exact pipe sizes just normally 1 is smaller then the other)

If that is the case you could install a valve by the pump.

[Splitrock]

A few of us add a valve between the pump and the water storage tank to isolate the tank during city water connection times.



The usual issue is pump check valve leakage and water tank overflow.

[xo1rider]

Originally Posted by Splitrock

A few of us add a valve between the pump and the water storage tank to isolate the tank during city water connection times.

The usual issue is pump check valve leakage and water tank overflow.

Thanks, what type of valve?

[drboyd]

Originally Posted by xo1rider

Thanks, what type of valve?

Full port ball valve, quarter turn, must be NSF 61 approved for potable water use. Just like the one in the picture above.

[xo1rider]

Originally Posted by drboyd

Full port ball valve, quarter turn, must be NSF 61 approved for potable water use. Just like the one in the picture above.

Do you keep valve closed on city water then manually open when using pump?

[Splitrock]

Originally Posted by xo1rider

Do you keep valve closed on city water then manually open when using pump?

Yes. And I have a second valve that isolates the city water supply for times the pump is used. I have experience with check valve failures on both ends. The valves eliminate dealing with failures during relaxation time.