Full way Termination valve

Good day all,

I'm sorry if this is a dumb new guy question but I don't want to ASSUME anything at this point with this rig.

2020 Heartland Fuel 352. Purchased new, 5 or 6 long weekend trips with less than 2,000 miles on it.

I believe I finally figured out that the black tank drain valve leaks, allowing liquids to slowly drain and leaving solids in the tank. Please don't ask how I made this uhh, nasty determination!!

I need to do a good black tank flush. I know where the connection is but I am a bit confused regarding the tag below the hose connection. (See picture below)

What is the "Fullway Termination Valve"? Also, is the "Tank Flush Valve" the hose connection above the tag? I THINK I know what is meant but sure don't want to ASSUME!!

Thanks in advance & have a great day!!


Camper flush connection.jpg


Well-known member
What they are basically warning you is to always have the black tank drain valve open when you flush the tank. If you run the flush with the valve closed, and happen to forget to open it, it could overflow up the toilet into your rig. That being said, after I have drained the black tank I usually close the valve, turn on the water for the flush and let it run for a few minutes to build up a little water in the tank. Then I open the drain valve and drain again. Never had a problem doing that as long as you don't let the flush water run too long.


Well-known member
Jim, whatever you do, do not get distracted while using the black tank flush. I have seen people get distracted and it overflow on their rigs.

We saw a RV in Houston, at Katy West RV Park, that the owner had hooked up their city water to the black tank flush line. They turned the water on, then left and went to eat. The park turned the water off, but it was after it was all over the top, side of their rig and down the site into the main roadway.
Short version, when they returned, they were upset, and the park made them depart, because they were going to wait for a RV detailer/cleaner to come in a couple of days. When they left there was a trail of residue all the way out the gate, past our site on the way.


Prolifically Gabby Member
You can get an inexpensive digital water meter to connect to the tank flush inlet to know how many gallons of water you’ve put into the tank (with the drain closed). And when done rinsing, you’ll know how much water you’re adding for the tank to be used again.

Not a good idea to drain the tank “dry” and start putting solid waste back into it. I usually added 5-7 gallons back into the tank after dumping.

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Well-known member
Don't ever turn the water on unless you have a timer on your person. That is the flush water. John's idea of the flow meter is a great idea as tank will fill at different times depending on the camp ground water pressure.