Good Day all,We are preparing for some extensive dry camping and I wanted to be sure my fresh water tank is full as it seems the last few day trips we ran out of water too quickly. Of course the LED gauge does not function properly.Here is what I did.Coach levelDrained fresh water tank from bottom.Turned hose on with a rate of 1 gallon per minute. ( based on jug and stop watch )Put extension on hose to go into the fill tube.Here is the puzzle, in 32 minutes water was flowing out the fill tube which tells me that is somewhere about 28-35 gallons in a 68 gallon tank. The rate of 1 gallon per minute should have taken about an hour.What could cause the tank not to "fill" up based on my math?How do you verify the tank is actually full when the gauge is not reading properly?Looking forward to your replies.

Pressure on municipal water systems isn't constant. Your test flow may have been at an unusually high demand time.I minute for a gallon seems very slow

Can you put more water in the tank after it overflowed? I know I am able to get more water in after the first "overflow." After the first overflow I reduce water pressure and it runs for some time.Also, RV makers sometimes, if not often, include the capacity of the hot water tank when stating fresh water capacity. I believe in your case it is a 12 gallon hot water heater so if they counted that it would take capacity down to 56 gallons. (How you are ever supposed to use the water in hot water tank, without draining it, is beyond me.)Mike

Agree with above. Maybe try to use something like a 5 or 6 gallon bucket to give you a better flow rating. One thing not to forget, is that when the claim is for a 90 gallon fresh water tank it is actually 80 gallons with 10 gallons of water for the water heater (assuming the W/H is 10 gal capacity). rockin'

You can get the $14.00 water meter from Amazon, works very well. Seems to be very accurate.

Agree w 2PMs. HomeDepot has this Water flow meter for about $16.

Fresh Water tank puzzle | Good Sam Community

Old-Biscuit
Explorer III
Aug 08, 2015
YES.........mfgs like to 'include water heater tank' in Fresh Water Capacity (Totals)

We have 70 gallon tank.......Sticking hose down fill tube and hose on full (50#) it takes roughly 10 mins to fill tank until water is running out overflow tube behind rear tire.
But that is AFTER I shortened fill tube....it was too long and had a big 'U' in it and would sag then blow water back out fill opening.

Fortunately fill tube, vent line are accessible thru removable panel in kitchen....water heater/water pump also.

Hope you can access it...check out how fill tube is run and vent line..if either kinked/sagging can casue issues filling tank
24fb_freedom
Explorer
Aug 08, 2015
I had the same problem on my previous rv, so what I did is carry 2 2x6x12" and drive up my two tires that where on the fill side to put the vent tube at the highest point to get all air out of tank.worked for me, just a thought.
Jetstreamer
Explorer
Aug 08, 2015
Depending on how your fresh water tank vent line is routed, if there is a low spot in it that would allow water to create a blockage, your tank will seem like it is full prematurely. This happens to me all the time. My solution is to carefully pressure feed water in as I fill the tank until water spurts out of vent line. One has to be diligent though to not overpressurize once the tank fills and possibly damage a tank mounting fixture.
Don't ask me how I know.
FlatBroke
Explorer II
Aug 08, 2015
Snowman9000 wrote:
On our Crossroads Cruiser, the pickup came off the side of the tank near the bottom but leaving the last inch or two in the tank. When the tank is only 6 or 8 inches tall, that's a lot of water that can't be used. The fix was to unscrew the piping elbow fitting and make up a new one that had a pickup tube attached to it. The tube was fitted so it ran down to the bottom of the tank.

Agree with this. And if you happen to be off level a bit it could even makes it worse. There was a bunch left when empty with our first trailer. I took off part of the bottom and put a couple of 2x4s across and under the tank on the opposite side of the pick up tube. Then the water had to go down hill. It got about every drop out after that.
Nutinelse2do
Explorer
Aug 08, 2015
SOLVED-- Thanks for all the replies and great input.

I traced down the water fill tube and needless to say it had more curves and dips in it than I care to show. I reran the fill tube so it had a single sloping path to tank and BINGO she has been taking water for the last 15 minutes. This has been resolved.. thanks again!!
bbeezzz
Explorer
Aug 08, 2015
For those that can not realign the vent tube, blowing air into to the vent outlet will clear the vent line of accumulating water. I carry a 2 foot clear 1/2 inch hose and place one end over the vent outlet and force out the water by blowing in the other end.

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