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1L243's avatar
1L243
Explorer II
Nov 24, 2015

New TT Black Tank Rinse Blocked

Trailer is a 2016 Keystone Premier 19fbpr. I was trying to winterize my trailer and when I came to blowing out the black tank rinse line. it was blocked no air or water would go in. This valve is located in the bathroom closet. The flow direction goes from the black tank rinse outlet to the black tank. That is way they have it plumbed. If I blow in the valve part (where my fingers are) in the direction of flow it shuts off by pushing up on a float. If I suck on it I get air. If I blow on the other end of the valve it's blocked?

I really can't tell if this valve is supposed to be a siphon valve or a back flow valve. It's only function is on the black tank rinse line. If its back flow valve shouldn't the direction of flow be from the black tank to the rinse outlet? But even if it was the valve is blocked in that direction as well.

The trailer is new and has not been used yet.



9 Replies

  • It's a small dealership and they work on their rigs in the lot. Think I will wait till the weather gets a little nicer..
  • 1L243 wrote:
    I by-passed the unit with pvc elbow and it's still blocked so now in the spring I guess I will take it in for warranty. I don't relish the idea if them tearing up the sealed underbelly so they can fix it...


    Why wait til spring time to take it in?

    Take it in NOW and have repairs done over the winter so it is ready to go camping come spring time
  • If it has to go in for warranty work, make sure (sure...sure...sure) you get it in on time. If it is one day past the end-of-coverage date, Keystone will tell you to pound sand.
  • I by-passed the unit with pvc elbow and it's still blocked so now in the spring I guess I will take it in for warranty. I don't relish the idea if them tearing up the sealed underbelly so they can fix it...
  • If you go to the manufacturers website, you will read that the stupid thing will leak in normal operation. I tossed the piece of junk and made a direct connection.
  • According the the diagram mine is installed properly. I priced one in town today and they want $79 for that thing.

    I am going to bypass it and see if the flush works or if the blockage could be further down the line.. If it still don't work, for $79 bucks it may have to go for warranty...

    What brand is that clear unit?
  • Mine was not tightened from the factory , tightened myself and kept leaking . turned out the hose was kinked about 4 " from the grey tank .fixed the kink and works as long as i do not put to much water pressure in it .
  • Diagram 'westend' linked shows complete installation & flow

    Water can be trapped in line section between connection on RV and to anti-siphon/vacuum breaker device due to check valve in the connection on rv

    Water on tank/flush side will drain into tank via vacuum breaker (open to atmosphere) and tank sprayer.

    Sounds like that device is defective as it should pass water (and air) thru it
    In thru bottom and out the side


    Here is a clear one
    Water coming in bottom pushes up on disc and o-ring seals it against open top (cap) ---- water then flows out side port to tank

    When water is turned off disc drops preventing any backflow back thru water connection and open top (cap) prevents anti-siphon action by breaking any vacuum