Black Water Tank Not Draining on my new 369RL

[Laura and Barry]

I just tried to drain my black water tank for the first time this past weekend.

Can someone tell me how to properly use the flush out for the black water tank? A note near the water connection says not to use it without having the "#$@%" valve in the open position. I don't remember the reference used for the valve name (thus the "#$@%") but whatever the name was it wasn't labeled on any other valves in the compartment. Very confusing.

I did run water to the flush valve because I of course wanted to flush the tank after draining it but when I opened the black water tank drain valve only a very small amount of the contents came out and that was in a small stream rather than in a big WOOSH like I'm used to with my previous trailers. After a while the stream stopped and I was left with 2/3 of the tank contents still in the tank according to the gauges inside.

This is my first 5ver so I don't know anything about how the utilities are configured. I crawled under the trailer to try and look at the actual valve to see if the lever was fully extending but of course all I could see was the black underbelly material that I suppose is part of the winerizing?

Anyone have an idea about how I should start troubleshooting when I visit my trailer again this weekend?

Thanks,
Barry

[Papa Smurf]

It is simply telling you to not use the tank flush without the drain valve open. The reason being, somewhere in the past someone has flooded their trailer, via the toilet, by using the tank flush with the drain valve closed... and forgot.

As to the slow drain, I would try to close and open the tank valve several times to see if you can break the congestion loose. I have seen picture of these tanks on this forum, and they are made to where everything settles towards the valve. If you have your solids sitting there for a while, I can see where they would get compressed into a drain blockage. If that fails, try to put a couple of packets of waste digester in the tank and let it sit overnight to see if that will help to free the blockage?

Hope this helps.

[Laura and Barry]

Thanks Papa Smurf!
I was hoping that the valve I was supposed to make sure was open was indeed the black tank valve itself but the warning sticker called it something like "throughway valve" or the like. It was draining a little like it was plugged but in 5 of years prior RV experience I never had that happen on either of my previous trailers (both bumper pulls). Is this settlement around the valve something unique to 5ver design?
Thanks again for your reply!
Barry

[Norcalrv1]

Get a flush king and you can back flush the tank and then drain it
I have used it many times to clean black tank
Works great


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[premove]

I have a 2015 369RL. It is in the shop for a several problems one of which is a hard to pull dump valve on the galley gray tank. While the tech had the underbelly off I asked to roll under the unit to see how the tanks are configured. I attached a crud drawing of the configuration of the tanks on mine. I'm not sure about which tank is the black or the bathroom grey tank, but as you can see the galley grey tank empties to the passenger side out a 1 1/2 pipe to the main 3 inch line to the dump outlet. This may help with your troubleshooting. Oh, the fix for my hard to pull dump valve was the tech lubed the valve.

[Dave and Monica]

I attached a crud drawing of the configuration of the tanks on mine. I'm not sure about which tank is the black or the bathroom grey tank, but as you can see the galley grey tank empties to the passenger side out a 1 1/2 pipe to the main 3 inch line to the dump outlet. This may help with your troubleshooting.

I think that you have the black and grey tanks reversed in your diagram. The black tank is normally as directly under the toilet as much as possible, which is more towards the door side of the camper. If you ever have the access panel off to the utility area under the bathroom, you'll see the drain and tank vent pipes entering the top of the tanks. The configuration I mention is what's true in our 337.

It's interesting to see how the galley drain is tied into the main drain line...I didn't know what side of the camper that the galley tank drain is. With this set-up, you need to empty the galley tank last to clean the main drain line of black water...not the normal rule of thumb of dirtiest first (black tank), cleanest last (grey tank). EDIT: Wouldn't matter as long as the black tank is emptied first.

Dave