Forum Discussion

Calicajun's avatar
Calicajun
Explorer
Sep 26, 2016

Holding Tanks

We were at Camping World looking at Columbus and Columbus Compass 5th wheels and liked what we saw on the lot. The only thing that worried me were the holding tanks. There seem to be bowing out under the unit.

Most all units we have looked at the under belly is flat but these units seem to bow down about 5 to 6 inches.
One to the units we looked at the under belly cover was torn so I could see one of the holding tanks. That tank was bowed on the bottom which was causing the pushing on the under belly covering.

No, I did not tear the under belly. Figured it was probably torn in transit but gave me a chance to see more of the underside of the unit.

My question is are holding tanks rounded on the bottom or are they suppose to be flat?

Thanks,
Craig

8 Replies

  • Calicajun's avatar
    Calicajun
    Explorer
    Sep 28, 2016
    No reply from Columbus yet but I will keep checking.
    Maybe Columbus will have a rep at the LA RV show this October 7-20.
  • MikeinSA's avatar
    MikeinSA
    Explorer
    Sep 27, 2016
    laknox wrote:
    MikeinSA wrote:
    Well this is timely :). We full time in a 2016 Columbus F375RL. We've been really happy with it so far, and have only had a few easily fixed problems. I've been dumping the black tank about once a week, and actually noticed a big bow under the black tank a few days ago. It's definitely the black tank - we have a clear section at the start of the drain line, and I can see the sludge flowing when I push up on the bow. I was going to call the factory this week and see if this is a warranty item. I'd say the bow is about what you saw 4" to 6", and doesn't go away after dumping. Let us know if you hear back from Columbus and I'll do the same.


    I'm surprised that you can see the tank, given that the vast majority of RVs have enclosed bellies. :h

    Lyle


    Sorry, guess I wasn't clear. I can't see the the tank. The bulge is in the coroplast underbelly liner. I know it's the black tank because I can see it discharging when I push up on the bulge in the liner.
  • laknox's avatar
    laknox
    Nomad
    Sep 27, 2016
    MikeinSA wrote:
    Well this is timely :). We full time in a 2016 Columbus F375RL. We've been really happy with it so far, and have only had a few easily fixed problems. I've been dumping the black tank about once a week, and actually noticed a big bow under the black tank a few days ago. It's definitely the black tank - we have a clear section at the start of the drain line, and I can see the sludge flowing when I push up on the bow. I was going to call the factory this week and see if this is a warranty item. I'd say the bow is about what you saw 4" to 6", and doesn't go away after dumping. Let us know if you hear back from Columbus and I'll do the same.


    I'm surprised that you can see the tank, given that the vast majority of RVs have enclosed bellies. :h

    Lyle
  • MikeinSA's avatar
    MikeinSA
    Explorer
    Sep 27, 2016
    Well this is timely :). We full time in a 2016 Columbus F375RL. We've been really happy with it so far, and have only had a few easily fixed problems. I've been dumping the black tank about once a week, and actually noticed a big bow under the black tank a few days ago. It's definitely the black tank - we have a clear section at the start of the drain line, and I can see the sludge flowing when I push up on the bow. I was going to call the factory this week and see if this is a warranty item. I'd say the bow is about what you saw 4" to 6", and doesn't go away after dumping. Let us know if you hear back from Columbus and I'll do the same.
  • Calicajun's avatar
    Calicajun
    Explorer
    Sep 27, 2016
    Sent an e-mail off to Columbus. Guess I will have to wait and see what they says about their holding tanks. I will update this thread when the reply comes through to my inbox.
  • Memphisdoug's avatar
    Memphisdoug
    Explorer
    Sep 27, 2016
    I'm just guessing but if the tanks look bowed when they are empty then they are probably molded that way. I wouldn't think that the empty weight of a tank would cause it to bow no matter how little support it had.
  • boogie_4wheel's avatar
    boogie_4wheel
    Explorer
    Sep 27, 2016
    The bottom of my waste tanks are rounded and sloped toward the valves so that they will drain when the trailer is level.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Sep 27, 2016
    Waste holding tanks (and fresh water tank) are FLAT on bottom so they will DRAIN

    Bowing tanks........new units..........not even used yet just means poor factory install-----lack of proper supports so tanks will most likely fail (fall down when filled or fall out during travel


    Pass!

About Fifth Wheel Group

19,020 PostsLatest Activity: Jul 26, 2025