Clogged black tank #1 in 2023 Montana Legacy 3901RK

[JFChavez456!]

Good afternoon fellow, Montana owners!
Our number one black tank appears to be clogged. We have been using septic tanks safe toilet paper for many years. We are on our maiden voyage. In this beautiful rig. We cannot get the black tank to clear out. Any suggestions?

[AZ Traveler]

Jane,

First - welcome to the forum!

Please give us a little more info for us to help you. What is your primary indication the tank is not draining; nothing coming out when the valve is opened or the unreliable tank level indicator?

Did you put 3-5 gallons of water in the tank before using it?

Does it feel like the valve is opening as you pull the black handle?

Have you tried to use the tank flush?

If you have put very little in the tank some models will not drain unless they are level side to side and a little nose high.

[Foldbak]

Welcome to the forums. What AZ said...

[rohrmann]

We had a neighbor in the park we use for our winter base a couple years ago had a pump service out to clean out his black tank. Turned out he never closed the drain valve and ultimately the poop pyramid developed and obstructed the pipe from the toilet so flushing waste had no place to go. Cost him $400, but he now knows to use the tank with the valve closed and drain it weekly. Hopefully your issue is different.

[Wayner197]

You could possibly have a plug like the cut out for the tank hole. Happened to us many years ago. Try using a back flush valve that connects to the outlet of your sewer. It uses your water hose to push water into the tank backwards forcing anything clogging the outlet back into the tank.

[GEugeneS]

Originally Posted by Wayner197

You could possibly have a plug like the cut out for the tank hole. Happened to us many years ago. Try using a back flush valve that connects to the outlet of your sewer. It uses your water hose to push water into the tank backwards forcing anything clogging the outlet back into the tank.

I had a clog like that many years ago and thereafter bought a "Flush King" fitting which allows you to easily back-flush in cases like that, and also to clean the tank. Additionally, I stopped putting T/P down the toilette and it now goes in the trash. To each his own, but haven't had a clog in almost 20 years now.

[Wayner197]

Originally Posted by GEugeneS

I had a clog like that many years ago and thereafter bought a "Flush King" fitting which allows you to easily back-flush in cases like that, and also to clean the tank. Additionally, I stopped putting T/P down the toilette and it now goes in the trash. To each his own, but haven't had a clog in almost 20 years now.

We stopped using “RV” toilet paper a good while back and started using Sam’s Club brand paper. Wife says it’s as soft as anything she’s used and it actually dissolves faster that Scott’s RV paper. As long as you use plenty of water, especially after you’ve dumped the tank you’ll not have a problem. We also use an enzyme additive. The tanks are designed to take the human waste and paper and if it wasn’t I wouldn’t buy one. The thought of stashing your waste paper in a bag and having to handle it later makes me want to throw up! But to each their own

[SaraLouwho]

After 20 years of camping and 8 years in the Montana, we had a similar problem. Just stopped draining. Luckily we had emptied a few days earlier. First thought was gate valve cable. Had that changed, no joy. Had to get a tank cleaner in. Seems that the chemicals in our urine, over time solidifies and make a shale like coating on the walls of the tank. This is called STRUVITE. Same compound as Kidney Stones. The tank cleaning man used high pressure and a lot of thumping with the nozzle to clear it out. Then we found the gate valve needed to be changed as it wasn't holding liquid back. Long weekend and we used the facilities sparingly. Been working fine since then. No large clumps of anything. We have always used Charmin in our rigs.

[harleyguy302]

I know this is a little old but just wanted to share. We had problems draining our 3901rk number 1 black tank and figured out the issue. The black tank is so far forward on this unit that if the nose of the fifth wheel is down hill at all the black tank won't drain. I always have an issue with this. It seems most places I go the dump station is usually angle down hill. So I have learned with stations I can and can not use. I think in the future I'm just going to start using the second bathroom black tank since it is more in the center of the unit.

[prndl]

Sooooooo, what ever came of this?