Black tank flush port question

[JohnZ3]

<b>Hello, I wanted to try out the black tank flush port today for the first time (using  clean water on a previously emptied tank). I carefully read all of the instructions and reviewed the bathroom vent and drain diagram. Both reference a shutoff valve that must be opened before flushing the tank.  I located the incoming water line under the front dinette seat, but there was NO valve anywhere. I then hooked up a hose and slowly added water which I could see (clear inlet hose) and hear water filling the black tank. When I opened the black tank tee handle at the rear, everything appeared to flush properly. My question is.....did the factory forget to install a shutoff valve or has there been a design change?  I can cut in a valve, if needed. Thanks, John</b>

[topgun2]

The shut off valve you are looking for should be under the dinette seat fairly close to where that line enters the black tank.  I'm not sure when the factory started adding that valve, but, I know that my Ollie (hull #117) does not have one.  Given that there is a "check" valve on that line and all other signs seem to indicate that the flush worked properly - I would not worry about it.  Next time you are at the factory you might want to ask about it or if it really bothers you, go ahead and cut it in yourself.

 

Bill

[Overland]

I do believe that they changed the design.  There was a discussion here a month or so ago about it, and some trailers have both a check valve and a manual valve, and some only the check valve.

 

 

 

edit - Bill seems to be a faster typer than me today.  ;)

[topgun2]

Today?

[ADKCamper]

I can confirm the above. We do not have a black tank flush valve either (Elite I hull#409 completed in late November 2018).

 

That's good, because if we did it would be impossible to get to. I can see most of the tubing from where it enters the hull to where it enters the black tank with a flashlight and a mirror-on-a-stick, but most of it is buried under or behind the furnace and there is insufficient clearance to get a hand/arm into or around that space to operate such a valve if it did exist.

 

The 2019 Owner's Manual (dated 1/8/2019) has removed the prior reference to this valve. See the "Oliver University" link under "Travel Trailers" above to download the latest owner's manual (now a single, merged Elite I and Elite II manual).

 

Tom

[BlaiddDrwg]

Page 75 of my 2018 owners manual shows this

[JohnZ3]

Thanks for your reply. The illustration is very helpful, but my unit (#405) clearly does not have a valve there.  Also, since there was a previous post from hull # 409 with the same findings, I'm guessing we were in the same class of not having one. Oh well.

[ScubaRx]

To put this issue to rest, the factory stopped installing the valve in the black tank flush line. There is still a back flow preventer.

[Geronimo John]

The only purposes for the black flush (BF) valve that I can think of are:

• If a jack ass wanted to, he could hook up a hose to your BF hose bibb and flood your trailer with poop while you are away.
• If the black check valve in the BF line were to fail, black water could end up on your hands when you remove the BF hose bibb cove.
• I would wager that a significant number of the owners leave it open anyway.....

On the positive side, not having that valve makes flushing your black tank faster by not having to go inside to open/close it.  

Either way, the odds are so low that it would appear that the cost of the BF Valve was not worth the extra.

[Mainiac]

Hull #211 a 2017 model has the valve. Only really open when winterizing and hand pumping antifreeze in. Does not get used much, if at all!.