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Molson
06-22-2020, 11:23 AM
I have a 2020 291rls and used it for the first time this past weekend.
I went to use the black tank flush and it did not work. There was pressure at the connection, however it did not flow.
Is there a shut off valve somewhere or is it something else?

chuckster57
06-22-2020, 11:27 AM
Welcome to the forum :wlcm:

Iím willing to bet the anti siphon valve is installed backwards. Itís probably under the bathroom sink and would require changing fittings. Since your under warranty I would let the dealer do it. Should have been addressed at the PDI by the tech that got your unit ready.

slow
06-23-2020, 03:48 PM
The pex on our passport had a kink in it that prevented water flow. An elbow took care of the issue.

Logan X
06-23-2020, 04:55 PM
Like Chuckster said, check the anti siphon valve. It’s probably under the sink in the bathroom. There is a arrow on it that shows the direction water flows. It might be installed backwards. It looks like this-

chuckster57
06-23-2020, 05:06 PM
Model year 2020 is the first year ďAspen TrailĒ trailers have come from the factory with a black tank rinser. So far EVERY unit we have touched has had it plumbed backwards :banghead:

Gary R.
06-23-2020, 06:05 PM
The black tank flush feature has never worked on our Alpine either.

I agree with the thought that the anti siphon valve was installed wrong.

However the valve is not under the bathroom sink. So the next logical (?) spot suggested was behind the shower. There is no panel to access the shower plumbing, so I removed the control valve assembly and looked for the anti siphon, but no luck there. Even if it was, there would be no way to grab it and make any changes.

So, I just gave up my search and use the clear twist on adapter, and connect it to the drain fitting. This also has a hose connection on it to allow a garden hose to be hooked up to back flush the tanks.

Works for me!

81SHOVELHEAD
06-28-2020, 01:05 PM
Like Chuckster said, check the anti siphon valve. Itís probably under the sink in the bathroom. There is a arrow on it that shows the direction water flows. It might be installed backwards. It looks like this-

Ours was installed backward on our 2014 28RLS. Not sure why they can't get it right?

skids
07-01-2020, 01:01 PM
Model year 2020 is the first year ďAspen TrailĒ trailers have come from the factory with a black tank rinser. So far EVERY unit we have touched has had it plumbed backwards :banghead:

Hey Chuckster, I have used ours only once and it made kind of a loud vibrating/humming sound. Is that normal?

JRTJH
07-01-2020, 02:35 PM
Yes, the rush of water through the valve causes a vibration/hum that can sound like it's about to self destruct.

One caution, don't use a 1/4 turn twist valve on the end of your hose or don't turn the water faucet on too fast. Doing that will put a "slamming water pressure" on the fragile valve and can break the interior, causing it to leak into the vanity. Slowly turn on the water to the flush system, so the valve feels a "gradually increasing water pressure". I use a regulator set at 40 PSI and haven't "lost a valve" since I started slowly turning on the water.

chuckster57
07-01-2020, 03:14 PM
Like John said itís normal. During PDI, I listen first for that familiar ďhumĒ that lets me know water is flowing.

tech740
07-01-2020, 05:45 PM
Like John said itís normal. During PDI, I listen first for that familiar ďhumĒ that lets me know water is flowing.

What??!! You make sure it works before the customer gets it? LOL That's what missing in most places now days.

chuckster57
07-01-2020, 05:50 PM
What??!! You make sure it works before the customer gets it? LOL That's what missing in most places now days.

Thatís because I was trained by a stickler for details..becomes a habit. Hopefully only about 26 more months to total retirement.

Phil Saran
07-05-2020, 01:19 PM
I have a 2019 Keystone Cougar 30RLS 34 foot 5th wheel and the flush
feature did not work either.

When I took it in for the end of the year check up and final warranty
list that item was on my list. They fixed most of the stuff not that.

I took the door off the cabinet and while laying on my back was able
to swap the two fittings so the black tank flush worked as it should.

Also had the wheel bearings repacked at that time and while putting
them back together the tech found that both axles were bent.

Luck for me that the Dexter Axles have a longer warranty than the
trailer does. So new axles were ordered and installed.