Water Tank Capacity Does Not Match Specs?

[JoeCampsNE]

We're getting ready to head out this weekend dry camping, so given the water tank issues frequently discussed in this forum. I've reinforced my tank supports with four tow haul straps.

I was filling the tank to sanitize it before the trip and thought I'd fill it short of the 58 gallon fresh water capacity as posted by Forest River on the spec sheet.

I figured I would fill it with 40 gallons, just in case they were including the 6 gallons in the HWT, leaving me with a 12 gallon buffer.

Well, I never got there.

I used a hose end flow meter to measure the amount of water I was putting in the tank and it only got to 32 gallons.

The tank meter in the unit indicated the tank was full and visual inspection confirmed that. The tank drain was open prior to me filling the tank, so I know it was empty and I also checked the flow meter using a portable 5 gallon portable jug and it was pretty much spot on.

Any thoughts are welcome because I'm legitimately confused.

[5picker]

What R/V do you have?

58 gallons sounds like a lot for most rigs unless it is a toy hauler or bigger rig.

As you have read, specs published and real world experiences are often somewhat different but 26 gallons is a pretty wide difference.

Set up a signature line so those viewing your posts will always know what R/V, tow vehicle, other items you have. (does NOT show in the mobile app but can be found)

[Flybob]

Depending on where the drain hose is located, you may actually had some water in the tank after emptying

[gbaldwin]

Surprise .....Surprise....Surprise

[bjaspud]

Specs for my Vibe say 40 gallons. Tank actually holds 33. Forest Rivers response was ‘read the fine print on the brochure. It’s says “specs may be changed without notice” or something similar.

[JoeCampsNE]

Thanks for the responses everyone, and the advice on the signature line 5picker. I have the 2017 MicroLite 21 FBRS. You can go their spec page here.

However, I just found specs for the "2017" model here, and it lists the tank capacity as 43 gallons. They must have upped the capacity after 2017 ( though everything else looks practically the same). So 43 gallons minus 6 gallons of hot water leave me with 37 gallons. Still not exact, but close enough for me move on to other things.

Sorry for the false alarm.

[woo10-210]

Originally Posted by bjaspud

Specs for my Vibe say 40 gallons. Tank actually holds 33. Forest Rivers response was ‘read the fine print on the brochure. It’s says “specs may be changed without notice” or something similar.

I'm pretty sure it states "fresh water capacity" not "fresh water tank capacity. Add 6 gallons for the water heater and it looks like you're golden if your tank is actually holding ~33 gallons.

[wmtire]

Originally Posted by JoeCampsNE

Thanks for the responses everyone, and the advice on the signature line 5picker. I have the 2017 MicroLite 21 FBRS. You can go their [URL="https://forestriverinc.com/rvs/travel-trailers/flagstaff-micro-lite/21FBRS/894"]

Sorry for the false alarm.

Well crud. I guess I have to put my pitchfork back in storage. It's going to take awhile for this tar to cool back down though.

When you do want to look up things on older models and such. I have found a lot of success using the way back machine. It takes snapshots of webpages and the links are sometimes still good. I've found a lot of older manuals and such this way.

https://archive.org/web/

[TitanMike]

My 2018 Microlite 25BDS only has a 43 gallon capacity tank. I have used the same meter to fill and have found that when I fill the tank then fill the lines and hot water tank I can top the tank off and get as much as 48-49 gallons in total.

For water "budgeting" purposes I just use 40 gallons. That lasts me at least a week. Of course it helps that I camp solo now.

[corky310]

Even though my tank capacity was listed at 48 gallons, the most I can get in is 30 gallons. I don't know why FR can't figure out what size tank to advertise when they sell it.

[Grapehound]

We have a Forest River fifth wheel with a "42 gallon" fresh water tank spec and I have never been able to get more than 32-33 gallons in it. I measure the water and pour it in the filler spout. We still run out of water if dry camping much more quickly (maybe 3 days) than we'd expect with limiting showers and water use.

Took it into the dealer when it was under warranty and they tore it apart and said the tank looks fine. No issues with the tank. It apparently it is just smaller than stated.

I think RV specs are sort of a suggestion of a hint of what equipment you might really have. We see goofy things in these RV's all the time. Just be happy everything's working!

[TitanMike]

Originally Posted by corky310

Even though my tank capacity was listed at 48 gallons, the most I can get in is 30 gallons. I don't know why FR can't figure out what size tank to advertise when they sell it.

Out of curiosity have you measured the physical dimensions of your tank? Multiply Length, Height, and width (in inches) then divide result by 231. This will give the capacity if the tank is completely full.

If it's close to 30 gallons it is what it is.

If 40 or more gallons it's possible that fill line and/or vent lines are improperly installed and air is getting trapped.

Another way to check is to fill until tank overflows then move TT back and forth, stepping on brakes firm enough to get water in tank moving. When finished with this "burping" process see if you can add more water and measure amount.

My old trailer, a 95 Terry, had this problem and it was simply that the vent hose was attached to the port the fill line should have been attached to. Water would reach vent, water would spew from vent hole, and lack of adequate venting kept tank from filling fully. Took me a couple years to wise up to what was going on but the fix was simple (after I could get to the tank that is).