Community Forums

Desdinova · 01-05-2021, 08:18 PM

I have a 2020 Vibe, with a 40 gallon fresh water tank.

Bottom line... Water starts coming out the overflow at about 26 gallons.

Over the summer we started using the fresh water tank as the pump in the rig is amazing and I can get a better handle on when we need to empty the holding tanks based on how many times I filled the fresh tank.

I have a meter on the hose and had been wondering if I was really filling the fresh tank but not paid it a lot of mind.

Today I decided to flush my fresh water system. And lo and behold i'm only able to put 26 gallons in and it starts to overflow. This is confirmed multiple times by 26-ish gallons is about 2/3rds full and that's where in the inside panel indicates. Three times my meter said I put in 26 gallons and water started coming out the overflow. I even did some rough math based on how long it takes to fill a 2-gallon bucket then how long it takes to fill the tank till it starts overflowing... all data points to about 26 gallons?

Thoughts? I'm about half-tempted to put valve on the overflow and ensure the water pressure is low and see if it "stops filling" at some point or just leave a faucet open and see when water stars coming out.

I'm dumbfounded and of course I can't actually see the fresh water tank.

TexasJeff · 01-05-2021, 08:47 PM

I hate to ask.. but no where in your post did you say how you were sure the tank was completely emptied. Are you sure you're starting from an empty tank? Are you just going by what the panel is reporting?

A32Deuce · 01-05-2021, 08:56 PM

Water heater is 6 gallons of that total and the amount in the lines is also some of that. If it goes in to the pump an inch or two up the side, that's also part of the total since you can't draw down to the bottom of the tank.

Desdinova · 01-05-2021, 09:23 PM

Sorry, I didn't mention it.. I additionally confirmed empty by turning on the pump and opening a faucet until it complained.

The hot water heater and the lines don't fill up until to turn the pump on and as I drained those anyway (I was doing a flush) I would have put MORE in not less.

And the hot water and lines are confirmed empty because after draining the system completely it takes a couple of minutes of open faucet before you get water with the pump on after having drained the system.

For further reference, although not scientific.. I run out of water after two showers and some daily use, but I can fill and drain the freshwater tank via use 3 times before I even need to look at the grey and black tanks .

The chances of my meter on the hose filling and the guage on the wall being both being innaccurate the SAME amount, is pretty astronomical. The other testing I did was just because I had the time and couldn't believe what I was seeing.

sanda · 01-05-2021, 10:21 PM

Quote:

Originally Posted by Desdinova

Sorry, I didn't mention it.. I additionally confirmed empty by turning on the pump and opening a faucet until it complained.

The hot water heater and the lines don't fill up until to turn the pump on and as I drained those anyway (I was doing a flush) I would have put MORE in not less.

And the hot water and lines are confirmed empty because after draining the system completely it takes a couple of minutes of open faucet before you get water with the pump on after having drained the system.

For further reference, although not scientific.. I run out of water after two showers and some daily use, but I can fill and drain the freshwater tank via use 3 times before I even need to look at the grey and black tanks .

The chances of my meter on the hose filling and the guage on the wall being both being innaccurate the SAME amount, is pretty astronomical. The other testing I did was just because I had the time and couldn't believe what I was seeing.

I wanted to check the accuracy of my RV readout for water tank capacity and gauge readings. I used a five gallon bucket under the tank drain and measured how many buckets drained out of the tank from full through the gauge increments. You might try this method to verify how many gallons your tank holds when full.

Desdinova · 01-05-2021, 10:35 PM

Quote:

Originally Posted by sanda

I wanted to check the accuracy of my RV readout for water tank capacity and gauge readings. I used a five gallon bucket under the tank drain and measured how many buckets drained out of the tank from full through the gauge increments. You might try this method to verify how many gallons your tank holds when full.

Great minds... just did that. 26. I also just verified the readout on my meter that I put on the hose.. by measuring into a bucket then measuring the bucket.

Also timed my hose fill rate which I calculated a few different ways is 3.625 gal/minute and the tank started overflowing at 7 minutes... or... drumroll 25 gallons (ok technically 25.375)..

My tank is not filling past 25-ish gallons.

Now that we have THAT out of the way....

Could there be something with the overflow. I'm not sure where it's attached or how. Could it have slipped further into the tank somehow? I can't see where it goes to the tank, but it's pretty far away from it. I'd have to take the membrane off to see up close, and I'm trying to avoid that.

Newmar2856 · 01-05-2021, 11:03 PM

Quote:

Originally Posted by A32Deuce

Water heater is 6 gallons of that total and the amount in the lines is also some of that. If it goes in to the pump an inch or two up the side, that's also part of the total since you can't draw down to the bottom of the tank.

What I think A32Deuce is trying to convey is some manufacturers have been known to put in a tank that holds 30 gallons of water, but also has a 10 gallon water heater, and then stating you have 40 gallons of fresh water. Also, depending upon where the overflow is installed on the tank you will probably lose a couple of gallons of capacity.

If you know where your water tank is installed, it’s pretty simple to drop the colorplast and look for your fill line and overflow.

rarebear.nm · 01-05-2021, 11:21 PM

If you can get access to the tank, measure it and then calculate the volume. Also as said above check the input and overflow connection points. 1 cubic foot equals 7.48 gallons.

Manufactures sometimes substitute different parts if they can not get what they normally use.

jrollf · 01-06-2021, 06:45 AM

Just a thought, maybe the pump pick-up hose/line isn't reaching the bottom of the tank so it can't get all the water out?

I've never looked inside the tank, so I'm not quite sure what the water pick-up looks like. On some non RV tanks I've seen the pipe connects to the tank at the bottom, if this is the case then my comment above doesn't apply.

Is there a dump valve on the bottom of the tank? There is on my Forest River TT. You could open it amd make sure the tank is truly empty then try and fill it again.

Mike8253 · 01-06-2021, 07:31 AM

Sounds to me like you need to have a talk with Forest River to assure the 40 gallon capacity number is accurate, that WH capacity is not included in the 40 gallons, and to understand how the fresh water tank is plumbed (both water pump pickup location and overflow).

Teamfoxy · 01-06-2021, 08:50 AM

Most tanks, that I have seen, have the fittings on the side of the tank near the top or bottom. So unless the RV is off level to put the exit fitting at the low side, the tank is not going completly empty. Unless the fill and overflow us at the extreme high point of the tank, the tank will not completly fill. A tank that is long or wide, but not high will be harder to fill to capacity or drain completely.
Also, I have yet to own an RV that had accurate level indicators.

Desdinova · 01-07-2021, 01:35 AM

We're actually using the RV this weekend and something has changed since purchase. I think maybe the overflow hose has somehow slipped deeper into the tank if that is possible. I guess I should mention it used to take much longer to fill. But, today while parking, the rig was tipped a little and water started pouring out the overflow. Thats never happened before.

Another oddity is.. when filling, when water just starts to drip from the overflow, I shut off the hose. You think it would almost immediately stop overflowing... but no.. I haven't had a chance to measure, but water starts pouring out and does so for several minutes, like its siphoning, like you'd siphon a tank. At least a couple gallons comes out.

I'm going to try filling with a faucet open. I wonder if air is the problem. Nowhere for the air in the tank to vent when filling.

rarebear.nm · 01-07-2021, 10:02 AM

In most cases the overflow is also the air vent for filling. In all tanks I know of all of the hoses are attached to a fitting that is either molded or glued on the tank. Thus a hoses does not have the ability to slip inside.

All overflow hoses I know of are small like 1/4 - 3/8" diameter. You're filling with a garden hose at about 60 PSI. The overflow hose has a hard time keeping pace with the volume of water entering the tank. Thus it will drain for some time. Early on, one time I was not watching the fill process close enough. When I came back by water was shooting perhaps 10 ft out of the overflow hose port. In some models the overflow exit port is fair amount higher than the top of the tank and in others it comes off the top portion of the tank and goes downward towards the ground. Thus they will behave differently.

Desdinova · 01-07-2021, 10:58 PM

Quote:

Originally Posted by rarebear.nm

In most cases the overflow is also the air vent for filling. In all tanks I know of all of the hoses are attached to a fitting that is either molded or glued on the tank. Thus a hoses does not have the ability to slip inside.

All overflow hoses I know of are small like 1/4 - 3/8" diameter. You're filling with a garden hose at about 60 PSI. The overflow hose has a hard time keeping pace with the volume of water entering the tank. Thus it will drain for some time. Early on, one time I was not watching the fill process close enough. When I came back by water was shooting perhaps 10 ft out of the overflow hose port. In some models the overflow exit port is fair amount higher than the top of the tank and in others it comes off the top portion of the tank and goes downward towards the ground. Thus they will behave differently.

Some really good points to think about. On this trailer, the fresh water tank is quite far from the inlet. The overflow, while I assume is near the top of the tank, goes down, and I'm guessing a fraction of the the distance of the inlet.

Tomorrow I'm going to measure how much overflows. Also going to attempt filling with a faucet open. I may also try to send my video scope into the belly to see if I can see whats going on.

Thanks