Black tank flush question

[rwmurphy15]

I have a keystone Fuzion 301 . I just took my first camping trip. And when I hooked up my hose to the black tank flush and opened the black tank dump valve turned on the water and nothing came out. Heard no spraying or nothing. I followed the black tank lines into the RV and they went to the kitchen sink area where I found this black part installed into the line then it went back under the floor again. Could this be the problem of not letting the water pass thus it. Could this be a check valve?

[MarkS]

That's the back flow preventer. They are notorious for going bad. They prevent black water from siphoning back into city water, if city water loses pressure.

[JRTJH]

You found the right "critter", as to whether it's installed backwards or not, if you aren't getting any water flow through it, I'd just swap ends and see if it works. When you winterize, don't forget to either take that black thing off and store it DRY on the shelf below its position or make sure you run RV antifreeze through the lines to protect it. They cost about $40 at the RV store and a brass replacement is about $15 at Lowe's.

[rwmurphy15]

That's what I wanted to know. I'll try installing it in reverse first if it does not work I'm heading to lowes for sure. Should just get one anyway. Thanks

[hankaye]

rwmurphy15, Howdy;

Check the arrow on the section that points to the Right in the photo,
it's supposed to indicate the direction of flow, is it pointing the correct direction???

hankaye

[rwmurphy15]

Well today I removed the back flow preventer and found that the in and out lines were switched. I had to remove the connectors at the end on the lines and swap them. Now water flows thru to the black tank sprayer. Must of been a Monday or Friday build day. Kind of strange because when we did a walk thru at settlement my wife noticed the radio/DVD player was installed upside down.Now you see how much of a hurry they are in when building there units.