Valterra Flush King - Montana Owners Club

navybanker · 01-10-2021, 07:17 PM

I need to replace for the second time the anti-siphon/back flow valve due to leaking. I know to not use the black plastic one currently on the unit. But what about the flush king? Researched it but prefer to ask you guys.

**Carl n Susan** · 01-10-2021, 07:44 PM

Many of us have just bypassed the POS valve by cutting the lines behind the convenience center and looping them together with a Shark Bite or similar. Put a real anti-syphon valve on the flush connection in the CC and you are good to go.

RMcNeal · 01-11-2021, 04:57 AM

I have a Valterra Flush King, but mine attaches to the sewer outlet below the rig. It has a valve and water hose connection such that I can run water to back fill the rig to whatever tank(s) are open. Is this what you are talking about?
The vacuum breaker/backflow preventer Carl mentioned is actually in the water supply line for the black tank flush. I did as Carl suggested since mine leaked the first time I used it under the bathroom sink. I bought a hose bib connected backflow preventer and put it on the inlet in the convenience center. I wasn't going to bother, but without it, quite a bit of water will backflow out into the convenience center every time I disconnected the hose.

ChuckS · 01-11-2021, 07:21 AM

I have never nor will I use the stupid built in black tank flush.. I use the Valtera flush king and have for the last 7 years... cleans out the black tank as well as both gray tanks... never and issue and that extra gate valve prevents unwanted and surprised spills when you take the sewer cap off

Daryles · 01-11-2021, 08:29 AM

There are some YouTube videos comparing the different sewer pipe end fitting flush valves. They would work great if they went straight into the tank. However the Montana has 3 bends in the pipe before reaching the black tank. Now IF you get a blocked sewer pipe, it could help with providing back pressure to break up the clog.
I do have the Valterra twist on gate valve. It prevents "surprises" when you take off the cap.

navybanker · 01-11-2021, 09:59 AM

Yes, talking about adding to the drain that you connect you sewer hose to. I have a "shutoff valve" on the end of the drain to avoid surprises. My major concern is like mentioned above is the one drain pipe branches into three going to each tank. Assume that you close valves to gray tanks to rinse just the black tank. Does this work well? You tube videos mention best if straight into black tank. Using the black tank backflow valve under the sink in bathroom, I turn the water off and disconnect hose to the water source and let the water drain out of the hose. Haven't heard of placing the backflow preventer behind the convenience center on black tank flush line???

**DQDick** · 01-11-2021, 10:34 AM

We've done what Carl recommends on each of the Montana's we've owned. On the last two we did it the second day we owned them. We use a backflow preventor made for outside home connections on the outside backflow connection and all is good. Got the backflow preventors on Amazon.

navybanker · 01-13-2021, 10:53 AM

I am not a plumber! Carl, when you say you cut the lines "behind" the convenience center are you talking about pulling the two lines from under the bathroom sink and making the connection in the pass thru storage? It looks like a connection in the pass thru would, if leaked, be better than under the bathroom sink. On the last trip, noticed the leak when looking in the pass thru and water coming down the line. Have researched the sharkbite connection and appears to be the easiest with less need for "new" tools. Am familiar with backflow preventer required on house facets outside. Learned this after moving this year to a newer house and had to repair one. Purchased a spare just in case after finding them. Camper is now stored an hour away so not as easy to check things as when it was behind my previous house. Sorry for such crazy questions. Dealer, where the camper is stored will not replace the backflow valve with anything they do not stock! (POS one) Said they got in trouble with 'other' solutions they did for people. Thanks

**Carl n Susan** · 01-13-2021, 11:31 AM

Remove the back wall from the pass through compartment. You should then be able to find the two clear pex lines going up into (and returning from) the anti-siphon valve under the bathroom sink. Find a convenient spot in the space behind the wall and cut the clear Pex there. There is no need to pull it down from under the sink (although you get extra points for neatness). The new connection will be hidden behind the rear wall once you re-install it.

navybanker · 01-13-2021, 12:44 PM

Whoa! If the line is behind the partition on my camper, maybe a leak somewhere else. I assumed the leak was from the suspect backflow valve but didn't have a lot of time to investigate since we were unpacking and winterizing to checkout of the CG before taking camper to storage. The water drops were from from a line about the middle of the ceiling in the pass thru. The line is exposed and not behind anything. Will go to the camper tomorrow and trace that line if possible. Also was going anyway to check to see if the connections to the valve were tight. Glad I am retired since this is about a full time job! Thanks again!

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