Fresh water tank doesn't show full

[joanjet]

Hi. Helping my son with his fresh water tank. This is what he has told me.

When I fill the tank, it has a relief valve that let you know when it's full. So when it's pouring out of the relief valve that means it's full. And when I fill it up it pours out but I don't see the gauge change.

Thanks for any advice I can relay to him!

[chuckster57]

There are a couple of different possibilities.
1) mis placed sensors on the tank- not to likely

2) wires from sensor pack not hooked up

3) failed sensor pack.

He will need to access the fresh tank and look at the side where the sensors are. The sensor pack is a red “dome” looking piece with wires coming out of it.

3 go to the tank and are color coded. If you look close at the pack it will have 1 wire attached to the trailer wiring, that is the “signal” wire. The 3 with eyelets attach to the tank. If your colorblind (like I am) the wire closest to the signal wire is the “full” wire. Just make sure they are tight and in the correct “order”.

[joanjet]

Thank you! Now he just has to find where the tank is

[jxnbbl]

It is usually under where you fill it.

[Martian]

Don't try looking for that relief valve as there isn't one. What he sees is the water coming out of the air vent from the tank. No valves involved.

[joanjet]

Thanks all! I will pass this on.

[Bandit12]

I use an inline water meter when filling my tank. I run a hose from the hydrant, to a shut off valve, to the meter, to my inline filter to the tank. When my meter reads somewhere around 15-17 gallons, the tank "burps" from the overflow vent. I briefly shut off the flow and when I turn it back on, the tank continues filling, while I hear the vent gurgling. My tank is supposed to hold roughly 54 gallons, but its usually overflowing at about 50 gallons. My tank level usually reads 2/3 full when the tank is over flowing. I use the meter whenever I add water to the tank, if going on a short trip when I know I have full hook ups, I'll put 10-15 gallons in the tank to use for potty breaks and washing hands until we get to where we're going. If I'm going to be boondocking, I want to know how much water I'm putting on board so I can roughly calculate my loaded weight. A full tank adds significant weight to the tongue. BTW, I have a second meter I use with my black tank flush. I store them on opposite sides of the storage bay.

[Pete C]

My tank usually only shows two dots out of three, the top sensor is so close to the top of the tank that water comes out the air vent before the last two inches of water fill the tank. With one dot left I still have 50% of my water

[dutchmensport]

Tank sensors: grey, black, and fresh, ... normally do not work correct most of the time. The best way to get them "clean" is to leave water in the tanks and then take the camper out for a drive over some curved roads so the water will slosh back and forth, sloshing against the sensors and cleaning off anything that may be affecting them.

In your fresh water tank, if using "hard" water consistently, it's possible there is a lime build up on the sensors themselves, which pretty much, will never come off with all the pulverizing in the world.

If you can add soft water to the tank, the soft water, over time, will dissolve the lime build up and sensors will start working again. But this may take several weeks to months to dissolve this way.

So, if there is a source to fill the tank with soft water, that has gone through a water softener, this will help, and in time, dissolve that lime buildup. But it does take time.

In my current home, we are an a well, very hard water with extremely bad iron. We got a home water system (Kenetico) and then added an iron remover (different company). The Kenetico system was a one time install, a one time payment. The iron remover tank is a rental. BUT! The water is as drinkable as bottled store bought water. In fact, we can't tell the difference.

We've noticed, over the last several years we've had the entire system, we don't get the lime build up any more and we don't have brown iron streaks any more either. The camper water system is much cleaner too.

Ours does not have chlorine at all.

So, if you are able to hook up, or fill the fresh water tank with "soft" water, this will help significantly .... in time.

[MattE303]

Originally Posted by Bandit12

if going on a short trip when I know I have full hook ups, I'll put 10-15 gallons in the tank to use for potty breaks and washing hands until we get to where we're going.

For what it's worth, I've read several times recently from knowledgeable RV industry folk that partially filling the tank causes more stress on the tank and mounts than filling it all the way because a lot of energy is generated by the water sloshing back and forth while driving. The exception is tanks that have internal baffles, but most don't.

[Bill-2020]

Originally Posted by jxnbbl

It is usually under where you fill it.

Not even close on our 5th wheel. Gravity fill is at the rear on the off-door side just above the power connection (great idea there, Keystone), tank is over the axles. Causes a problem- there is too much of a belly, or bellies, in the vent hose along the path from the tank all the way back to the fill port. Water from traveling sloshes up into that hose, and stays in the bellies of the long run (about 10-12 feet) so the water acts like a plug and I can only get about 12-15 gallons of water in the tank before it backs up out the fill port. If I blow the vent tube line clear with compressed air first it’ll fill all the way. Yes, there is an option of rerouting the overfill/vent hose so that it vents directly to the ground next to the tank or an attempt to pull the hose taught and secure it so that it has a slight uphill elevation to it so water doesn’t pool. Either of these will be a solution, just a matter of doing it. We never boon dock so a full tank is never needed for us really.