Black tank flush question

[PacificTJ]

Hello all,
New TT owner and just took her on the maiden voyage. Everything went smothly, except for flushing the black tank. We have a 2018 Rockwood MinLite 2504s, and it has an external black tank flush nozzle.

After draining both the black and gray tanks, I attached the hose to the exterior flush connection with the black tank valve open. While the hose pressurized and filled with water, nothing drained into the sewer hose, and the black tank didn't fill up at all.

Did I do it wrong, or is there another valve I needed open somewhere?

Thanks for the help.

[emjayuu]

Something is definitely strange as the water should have gone somewhere. Hmmm

[Kaadk]

Two possibilities pop to mind:

1) Perhaps you had some blockage. It's nasty, but sometimes the toilet paper will wad up and clog the drain especially if a large piece happens to be near the end of the draining and it doesn't have sufficient water behind it. Usually just getting some more water into the tank will provide the necessary pressure to dislodge it, but you need to carefully monitor the amount of water you add so you don't have a situation like this:

http://www.forestriverforums.com/for...ush-67565.html

If you've added 5 or so gallons and it hasn't started coming out yet, then it's more likely:

2) The check valve on the black tank flush is installed backwards. I haven't experienced it personally, but there have been a few reports of this occurring, where the check valve was installed in the wrong direction. If so, should be a simple repair to fix it. However, since this is your first time using it, I'm going to go out on a limb and assume this unit is fairly new to you. If so, I'd recommend making the dealer fix it under warranty if they're fairly close by. Why should you have to deal with it if it's new right?

On the other hand, if the dealer's too far way, or you just feel like fixing it yourself, it's should be a simple repair. Just need to open the panel on the backside of your flush hookups to look for something that looks like this:


(Image courtesy of Amazon: https://www.amazon.com/JR-Products-5.../dp/B0095TD5S6)

The line from outside should come into the bottom of the 'box' and then head out the side of the 'box' to your black tank. (if I remember correctly, I don't have my trailer nearby to go check) If they're reversed then you just need to turn it around.

Lastly, I see you mentioned you drained the black, grey and then went to flush. Typically, I do it in this order:

1) Black
2) Flush
3) Grey

That way, if there's anything left in the sewer hose after the black flushing is done, the force of the grey draining washes it away. By doing Black, grey then flush, your leaving yourself more cleanup to do.

Oh, and welcome to the Forums!

Mike

[cavie]

New trailer. Maiden voyage. Are you sure you weren't hooked on the city water or fresh water tank fill? It's not out of the realm of possibilities that they are labeled wrong.

[SlfMdeFam]

Originally Posted by cavie

New trailer. Maiden voyage. Are you sure you weren't hooked on the city water or fresh water tank fill? It's not out of the realm of possibilities that they are labeled wrong.

X2-I was thinking this same thing...

[lewisra]

You should be able to hear the sprayer water hitting the plastic tank when it's turned on. Also, I would start the "flush" before I open the valve to release. Unless you've been out for a couple weeks it's probably not near being full. Or at least start the release and then immediately the flush. You don't want the "heavies" to hit the bottom and clog the release point. My guess would be the valve was clogged. Get a clear short extension for release pipe so you can see what coming out or not coming out.

[MillMitch]

Had something similar with our maiden voyage last october. Drained the black tank, and I have a clear elbow so i know stuff came out. Hooked up the black tank flush and turned on the hose and nothing. Probably a full minute went by, which is a reeaallyy long time when you're dumping water into your black tank and nothing is coming out, before something broke loose and black tank emptied. From now on, black tank starts with 4 or 5 gallons of water before we leave the house.

[Semperfi24]

Would be surprised if they had the hose hooked up to the freshwater. On the 2504S the freshwater is on the driver side way up at the front of the trailer. The black tank flush is on the back wall of the camper. It is "possible", but I would think that is probably the least likely.

But if this was a "hooked to the wrong inlet" scenario, my thought would be that the OP hooked up to the antifreeze inlet, which is located about 8" above the city water inlet. Hooking up to the antifreeze inlet isnt going to accomplish anything because there is a valve, plus it uses the water pump.

Only way to know for sure is if the OP can let us know which of the hose hook ups they were using. Freshwater at the front of the trailer, Antifreeze just above the city, or black tank flush located on the back wall (near the spare tire).