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Topic: Grey/black water tank dump (new owner of a used FT) (Read 2103 times) previous topic - next topic

Grey/black water tank dump (new owner of a used FT)

Be gentle folks. I just bought an 08 nimbus from mot. My third rv. First 2 were Monaco (Executive then Navigator). I'm not looking back, this coach exceeds my expectations. But I have a question that right now I can only guess at the answer. Why is there a single pull for tank drain?  In the past I have found separate drains to be useful. Enlighten me!

Re: Grey/black water tank dump (new owner of a used FT)

Reply #1 –
Doesn't the Nimbus have one combined tank for grey and black? I may be wrong but I I thought I've read that.

Congratulations on the coach!

Re: Grey/black water tank dump (new owner of a used FT)

Reply #2 –

A new-to-you coach.  Wonderful.

The 07 Nimbus appears to have two waste tanks.  The 08 may only have one, a single valve handle is a good clue.  It is pretty common on later coaches to have a single waste tank.  Should be fine.

Many of us swear by the magic mix, 1 gal warm water, 1/4 cup Dawn detergent and 1/2 cup of Calgon Bath Oil beads (Walmart, your choice of floral scents). Mix, dump in a couple batches down the toilet.  We toss in a BioTab as well.

Amazon.com: Walex BIO-11530 Bio-Pak Natural Holding Tank Deodorizer and...

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Grey/black water tank dump (new owner of a used FT)

Reply #3 –
Congrats on the new coach!

Re: Grey/black water tank dump (new owner of a used FT)

Reply #4 –
WELCOME TO THE FAMILY!! !! !!! !!

Re: Grey/black water tank dump (new owner of a used FT)

Reply #5 –
Ok.  It appears that it is a single waste tank. I was incorrectly assuming that it was a single handle dumping 2 tanks. I would have looked it up myself but am currently traveling without the coach and curiosity got me. Until today I had never heard of using a single waste tank. All my preliminary info came from the 07 brochure on beamalarm.

Re: Grey/black water tank dump (new owner of a used FT)

Reply #6 –
Quote from: Deg503 –
Why is there a single pull for tank drain?  In the past I have found separate drains to be useful. Enlighten me!
Besides having only one waste tank dump handle, you should also get a clue from your tank level monitoring display.  What does it show?  If it only shows two levels - fresh water and waste water - then you have your answer.  If it is like every other Foretravel coach I've ever seen, the waste tank(s) will be larger (capacity) than the fresh tank.  When you have used up all the fresh water in your tank, time to find a dump station!

Re: Grey/black water tank dump (new owner of a used FT)

Reply #7 –
Quote from: Deg503 –
Ok.  It appears that it is a single waste tank. I was incorrectly assuming that it was a single handle dumping 2 tanks. I would have looked it up myself but am currently traveling without the coach and curiosity got me. Until today I had never heard of using a single waste tank. All my preliminary info came from the 07 brochure on beamalarm.

I think FT refers to it as a "consolidated waste tank".  Initially everything went into that one tank with no ability to let the grey water flow directly out.  Later they added a grey water bypass, but I'm not sure if it was made standard or was an option.  If yours doesn't have a bypass do keep an eye on the tank levels if you have a washer/dryer and use it.

Re: Grey/black water tank dump (new owner of a used FT)

Reply #8 –
Our 12 nimbus has the gray water bypass. It has the single tank and with frugal water use I have gone 9 days. That means marine showers and washing dishes carefully.  Other wise no problems. Now if the switch for the city water bypass was just as easy.

Re: Grey/black water tank dump (new owner of a used FT)

Reply #10 –
TM, Chuck is saying that in coaches with a single waste tank it will have a larger capacity than the fresh water tank.  In coaches with gray and black tanks their combined capacity will be greater than the fresh water tank.  If you start with a full fresh water tank and empty waste tank(s) and you use water from your tank you are very likely to never have a waste tank capacity problem.  If you use city water then you need to watch your tank levels. 

The gray water bypass lets gray water go directly to the sewer hose hookup without going into the single waste tank. 

Re: Grey/black water tank dump (new owner of a used FT)

Reply #11 –
I guess "like every other Foretravel I've ever seen" threw me off Roger.

Thanks for clarifying.

Re: Grey/black water tank dump (new owner of a used FT)

Reply #12 –
Where is the switch or control for the bypass? My friend has a 2008 Nimbus?

Re: Grey/black water tank dump (new owner of a used FT)

Reply #13 –
I also have a 2008 Nimbus... I have two separate tanks and valves for dumping.. no bypass switch .. not sure what that is..

Re: Grey/black water tank dump (new owner of a used FT)

Reply #14 –
Quote from: Bigoil76 –
I also have a 2008 Nimbus... I have two separate tanks and valves for dumping.. no bypass switch .. not sure what that is..
If you have two separate waste water tanks and two dump valves, then you have no need for a bypass switch.

Coaches with a single combined waste water tank (gray and black water run into the same holding tank) sometimes have a (electric I assume) switchable valve to allow diverting gray water flow around the holding tank and directly out the dump valve.

You may ask "Why do that?"

Here is my attempt to justify this device:  It has never been recommended, when parked where you have full hookups, to keep your black tank drain valve open all the time.  Yes, I know, lots of owners do just that.  The theory is, without some liquid in the bottom of the black tank, the solid waste could "pile up" (pardon the imagery) and dry out, making it very difficult to remove by normal dumping actions.  If you leave the black tank dump valve closed (even with full hookups) and wait to dump until the tank is nearly full, then the solids stay mobile and the tank gets "flushed out" more thoroughly.

SO, with a single waste tank and a bypass valve, you can divert the gray water around the tank and out the dump line, while allowing the tank to fill up (with black water) until ready to dump.  :thumbsup:

If anybody else has a better idea, bring it on.

Re: Grey/black water tank dump (new owner of a used FT)

Reply #15 –
with older coaches, if the grey water is not dumped in time
it will back up into the shower.  what if that happens with
a coach with a single tank? yuk

Re: Grey/black water tank dump (new owner of a used FT)

Reply #16 –
Quote from: wayne m –
With older coaches, if the grey water is not dumped in time it will back up into the shower.
What if that happens with a coach with a single tank? yuk
Same thing as what happens with 2-tank system, but a much more visible and smelly indication of trouble.

If you don't dump the black tank on a 2-tank system, the first clue there is a problem might be when you attempt to flush the toilet and the "contents" just sit there because there's no space left for "it" in the tank.

This has happened to forum Members.  :o

Re: Grey/black water tank dump (new owner of a used FT)

Reply #17 –
Thanks for the help 🤠

Re: Grey/black water tank dump (new owner of a used FT)

Reply #18 –
When I got the current coach I was concerned about the  1 tank system.  So far after 3 years I have no problem with it.  If my wife washes clothes every day we have gone 4 days before I had to dump.  I could use the bypass but I figure I am better off filling up the one tank and dumping it.

Re: Grey/black water tank dump (new owner of a used FT)

Reply #19 –
When I had the Monaco I had grey water backing up into the shower once. When I
got home I put a check valve in the shower drain line and that fixed the problem.