Gray Drain

[Aidan Trainor]

Hi , I'm new to the Oliver scene. We had a 5th wheel and are getting use to the Oliver Elite 11 . I have one question ,  why does the gray tank drain very slowly. The black tank drains quickly. Has anyone had or have the same issue? 

Thanks Aidan 1455

[Townesw]

Hello Aidan.  The gray tank will drain quicker if the front of the trailer is raised a little. Raising the curb side a little near the end of the process also helps. The gray tank is long, narrow, and thin and the drain valve is on the left side rear corner of the tank. 
 

 

The gray tank level sensor on hull 313 is located where the yellow blotch is shown on the picture below. My tank level could show 0% and still have water in the rear of the tank if the nose is too high. 

 

 

Bill

Edited 1 hour ago by Townesw

[Aidan Trainor]

I did raise the front put it still seams to take a long time to drain , not of water flow. Im used to a large flow when I pull the handle , very very slow stream.

[Townesw]

My gray tank was draining really slow one time. I filled it then drove around and went home and backed it down a slope and dumped. The water came out with force and brought out a nasty looking slime. Since then we have added dawn dish washing soap and traveled with some water in the gray tank. I try to dump the gray soon after getting home while backed down a slope so as to get really good flow. It still drains slow due to the size and layout of the tank but it was much better after I got the algae (?) out of it. 

[Townesw]

Look under street side bunk. Make sure valve is open all of the way when handle is pulled. Also if you’re going to fill it lay a water hose in the shower pan (but watch it REAL close) and really raise the nose so you are washing the bottom of the tank. Fill tank until water stops draining in shower pan. Be sure to quickly turn water off. Open the valve and let it rush out. Do it a few times. Watch what comes out if you can. You know that white snot that grows in HVAC condensate pans and lines? I think similar stuff grows in gray tanks. I think #1455 has sat unused and you have a build up in your tank. 
 

I think people set these trailers up level, hook up to the sewer and open the drain and let the water out as it is filled. This lets solids settle on the tank floors. We were told to keep the drains closed and only dump when the tanks were filled so that solids could be flushed out. We always  dump black first. Then we use the flush inlet and fill and drain the black tank 3,4,5 times until I don’t see anymore floaters (we don’t put paper in our black tank) in the clear elbow at the sewer connection. Then I open the gray tank and let it drain while I do something else. After a few minutes the gray tank level is 0. Since I got that gunk out of my gray tank I haven’t had any problems. It will still drain slow but I eventually get to 0%.

Edited 34 minutes ago by Townesw