Black tank overflow?

[Jayco2015JayFLIGHT]

Hello my black tank answers always say full. I bought this stuff called unique sensor cleaner and to see if they can restore them. It says to fill the tank with water and then add 16 oz. How do I know when it's full it seems full when I looked down the toilet but it keeps taking water and doesn't seem to be getting any more filled. I read some things about it can overflow into a vent pipe out the roof or in your walls. I'm nervous I might have filled it too much???

[sturgissteele]

I'm not aware of an overflow, other than backing all way up the toilet, then onto the floor. To fill the tank, you would fill from the top and you just keep an eye on it as it fills up.

Others have filled it up 1/2 - 3/4 then add a big bag of ice just prior to leaving for the campsite. Then it swishes around in there knocking the crud off of the sensors and walls as you drive. I'd have to search it up, but I think they add something like a detergent to help clean stuff up, too.

[RoadrunnerII]

We use any laundry detergent and Calgon or borax laundry additive to soften the water
Sensors work most of the time.
Doing a really good rinse helps... Leaving water in the tank when you travel allows some agitation

RoadrunnerII

[Parrott]

I just installed the Seelevel system. Sensors are mounted on the outside of the tank. Works perfect. Easy install as long as you can get to the tanks.

[Jayco2015JayFLIGHT]

Originally Posted by Parrott

I just installed the Seelevel system. Sensors are mounted on the outside of the tank. Works perfect. Easy install as long as you can get to the tanks.

I'll look into it. Hopefully it doesnt come to that 🤞

[GregandKelly]

If you are filling it from the toilet, the water level would show there before any chance of coming out the vent stack... the vent stack overflow happens when you use the black tank flush with no valves open and get distracted and forget about it. The water then has no where else to go but up.

[AZMarine]

I saw this < P3 P0550 Water Meter > on a post some time ago & purchased it from Amazon for about $21.00. This allows me to see how much water I am putting into my tanks. This has worked great, its small, convenient & simply attaches to the hose.
Also, after dumping & flushing my black tank (it is a 42 gal tank), I put in about 15 gal with a cup of fabric softener so it sloshes around while we go to the next site, or home. I might try the bag of ice trick as well on this summer trip.

[Jayco2015JayFLIGHT]

Originally Posted by GregandKelly

If you are filling it from the toilet, the water level would show there before any chance of coming out the vent stack... the vent stack overflow happens when you use the black tank flush with no valves open and get distracted and forget about it. The water then has no where else to go but up.

I hear you. That's kinda what i did. I was filling with the shower head and flushing over n over. It looked full then I kept holding the flush. I wanted to tippy full it to make sure I got the top sensors and it seemed as if it wouldnt get any fuller. Then I started wonder where the water was going. I got out and looked everywhere to make sure nothing coming out the roof. But I belive I was probably into the vent stack a little. Thank god I stoped. I went and let a gallon or 2 out for that reason. It's been soaking 48 hours now. Says 12 hours or more the more the better. I'll probably drain it tomrow 72 hours and hope the sensors are working