I have noticed that I can have a full fresh water tank (65 gal in my JAYCO 36RLTS) when I pull into a site with water available. When I hook up to this “city water”, after some period of time the water in my holding tank is gone. Is this a siphon issue, or is it supposed to be that way? I have separate valves to open or close for “city water”, “city water fill”, “normal”, “winterize”, etc.Thanks for the help!David

If I understand your post, the NO it should not do that. And I don't understand how it is happening unless the pump is on, and is running as you use water. Or you have a leak.

Valves are in the wrong position. Check owners manual. Label in compartment should show correct valve positon for city water usage.

Did you turn the pump switch off? If the city water pressure is less than the "on" pressure for the pump, the pump will run and deplete your onboard tank. Do you hear the pump running when you open a faucet?

IF you use a water regulator the pump may kick in to supplementIn some parks again the pressure in the city line may be less than the pump pressureYou may also have a leakThis is in addition to the above comments Turn pump off when hooked to city and see what happens,

Your condition is not normal. So "No" is the answer to your question.

Fresh water use | Good Sam Community

19 Replies

dewey02
Explorer II
Dec 10, 2017
oldtrojan66 wrote:
By the way, and just for clarification, old trojan does not refer to a used prophylactic. I was the mascot at my high school 50+ years ago and dressed like a trojan soldier and graduated in 1966!

In these days of age-old indiscretions coming back to haunt fellas, I thought I’d better explain!

Y’all be safe out there. It’s a jungle!!

Thanks for the clarification. On a similar note:

I heard a story that many years ago, when the Notre dame fighting Irish played the USC Trojans, some fans in the Notre dame section held up a huge white sheet that had the following words printed on it:

Even the Pope hates Trojans!
oldtrojan66
Explorer
Dec 10, 2017
By the way, and just for clarification, old trojan does not refer to a used prophylactic. I was the mascot at my high school 50+ years ago and dressed like a trojan soldier and graduated in 1966!

In these days of age-old indiscretions coming back to haunt fellas, I thought I’d better explain!

Y’all be safe out there. It’s a jungle!!
oldtrojan66
Explorer
Dec 10, 2017
Joe417 wrote:

#1 connects the pump input
#2 connects the tank output. It feeds the water pump.
#3 connects the tank input.
#4 connects the external hose fitting
#5 connects the camper water lines to the system
Joe417 wrote:

My panel looks just like this except the word country does not appear. When I choose city fill, out city water, I must turn the pump switch to off, or it will run continuously. Therefore the pump cannot run when I am hooked up to city water and have selected city water on the panel.

No offense meant to anyone and none taken from any answers. For me at this time, it is just one of those things I can’t explain, and I can live with it.

Thanks all, david
oldtrojan66
Explorer
Dec 10, 2017
Old-Biscuit wrote:

And what is this about having to unpack & dry out basement compartment ---twice a year :H LEAKS!

Well, Old Bis, it’s about the tank gauges being totally unreliable. Me waiting till I see water standing in the sink or shower floor, cause I’m not usually in a FHU space. And being a forgetful old man who has water drip from above into the very back part of the basement. So I take everything out. Out a fan in there n dry stuff. Perhaps I exaggerated the number of times, but more than once is enough...
Joe417
Explorer
Dec 09, 2017
I agree with Old-Biscuit.

You may have already looked in the Jayco documents but if yours is similar to the diagram below, then one of the valves shuts the input to the tank and another shuts the output from the tank. Yours could be different since it's a different year.

I mapped this out once and if I'm not mistaken:

#1 connects the pump input
#2 connects the tank output. It feeds the water pump.
#3 connects the tank input.
#4 connects the external hose fitting
#5 connects the camper water lines to the system

If valve #2 is closed (set to city water) on our tank nothing can come out unless there is a hole between the tank and the valve.

There is an overflow in case you overfill the tank but it is attached to the top of the tank and will not siphon water out.
Old-Biscuit
Explorer III
Dec 09, 2017
City water can not siphon water from fresh water tank

Water leaves a fresh water tank via pump suction, siphoning out vent, siphoning out overflow or thru tank drain

Water goes into tank via gravity fill port OR a 'fill' valve
If in city water the 'fill' line would be flowing water into tank if fill valve was cracked open or leaking thru as it has city water pressure against it

Pump ON and city water pressure low enough that pump runs using up water in tank
Siphoning out vent, overflow
Tank drain leak

And what is this about having to unpack & dry out basement compartment ---twice a year :H LEAKS!
enblethen
Nomad
Dec 09, 2017
The venture action can be caused by the fill valve partially open.
oldtrojan66
Explorer
Dec 09, 2017
I think Rallye2000 has a likely solution. I have not had the basement empty to check out plumbing for a bit. (I usually have to empty about twice a year for some reason about water being in the wrong place and wanting it to thoroughly dry. I’m gettin’ pretty good at packing n unpacking!) I think the only valve that shuts off tank n turns on City is the panel of levers I mentioned before.
I guess I could have much worse problems. It was just one of those things that make you go, “Hmmmmmm”!
Thanks all, david...
Rallye2000
Explorer
Dec 08, 2017
Sounds like your water tank is draining because the city water passing by the tank outlet is acting like a venturi. Think of a carburetor and the venturi effect pulling the gas into it. Could be happening to your water tank.
oldtrojan66
Explorer
Dec 08, 2017
Still a mystery. No one has, as yet, offered a suggestion I have not tried. The pump os turned off, as previously stated.
Thanks, again!
David

Forum Discussion

Fresh water use

19 Replies

About Technical Issues

Related Content

Fresh water tank

fresh water hose

External Water Fresh water Tank

Fresh water Hook-up

Waste water totes for fresh water