Forum Discussion

swimmer_spe's avatar
swimmer_spe
Explorer
May 22, 2023

What happens when you overfill tanks.....

I know if you overfill your fresh water tank, generally, there is an overflow and it dumps on the ground. What about your grey and black? Does it just start to come out of those things that drain there?
  • 2112's avatar
    2112
    Explorer II
    My gray tank is full when the shower no longer drains.
    My black tank is full when the toilet burps when I flush.

    My gray fills up long before the black. I put a valve on the main drain pipe where you connect the drain hose. With that valve closed I open the gray valve, wait a few second, then open the black valve to move some gray water to the black tank. Then close both valves. That gets me at least another shower before to the dump we go.
  • The FW tank has an overflow at the top that may (should) feed a hose to a screened vent.
    The GW & BW tanks have large vent pipes that extrude through the RV roof, to try to avoid any smells. They will back up through the drains if overfilled or be easily visible in the large toilet ball valve.
  • swimmer_spe wrote:
    I know if you overfill your fresh water tank, generally, there is an overflow and it dumps on the ground. What about your grey and black? Does it just start to come out of those things that drain there?


    You’ve had campers-how long? Do these questions just pop into your head randomly and keep you from getting good sleep or??
    And what are “those things that drain there?”
  • rk911 wrote:
    swimmer_spe wrote:
    I know if you overfill your fresh water tank, generally, there is an overflow and it dumps on the ground. What about your grey and black? Does it just start to come out of those things that drain there?


    yup, usually at the lowest point which is the shower. In our first MH the shower was plumbed into the black tank.


    Uuuuurp!
  • swimmer_spe wrote:
    I know if you overfill your fresh water tank, generally, there is an overflow and it dumps on the ground. What about your grey and black? Does it just start to come out of those things that drain there?


    yup, usually at the lowest point which is the shower. In our first MH the shower was plumbed into the black tank.
  • swimmer_spe wrote:
    I know if you overfill your fresh water tank, generally, there is an overflow and it dumps on the ground. What about your grey and black? Does it just start to come out of those things that drain there?


    Yes... The grey tank will typically back up into the shower or tub, and the full black tank will not allow anything to flush and may back up the vent pipe making for a nasty surprise when the toilet flush valve is opened.