black water amount to trigger sensor

I have a 2019 RG26, 35 GAL BLACK WATER TANK. LIGHT NEVER SHOWED OVER EMPTY I DUMPED EVERY OTHER DAY SO WOULDNT OVERFILL. JUST THE TWO OF US AND I WAS AWAY EVERY DAY JUST THERE AT NIGHTS. HOW MUCH DOES IT TAKE TO SHOW MORE THAN EMPTY, ANYONE ELSE HAD THIS PROBLEM? MAY NEED TO TAKE IT BACK TO DEALER ONLY HAD IT TWO MONTHS.
THANKS FOR THE INPUT

Hi S.W. Smith,

Welcome to the Heartland Owners Forum.

We have a 45 gallon black tank and it's usually getting full at 7 days (2 of us). If yours doesn't light up at all, you may have a problem with the sensor or test panel. Another possibility is that the dump valve has a slow leak (often caused by trapping waste material in the blade channel).

Next time you dump the black tank, close the dump valve and run the black tank flush for 5 minutes. Unless you have very low water flow, that should put 10-20 gallons in the tank. Use the timer on your phone and don't get distracted if someone walks up to talk with you. If the test panel still shows no lights, it'll need to be serviced.

Don't forget to let the water out of the tank.

The test panel lights are usually pretty useless as a little paper or waste gets stuck to the sensor and it always reads full. Most of us just dump the tanks on a schedule. Another method is to wait until the toilet "burps" while flushing. That indicates the tank is full.

Welcome to the forum! I don't believe you have a problem... we camp with 5-6 people (most of the time there's more than that using the toilet) and can go all weekend without the black tank getting full.

Some other people may comment on this but you are dumping the black tank too often. By dumping before you have sufficient liquid supply in the tank, a lot of solids get left behind. You did not say anything about using the flush system. When you drain the tank every other day, what do you do to rinse out the drain hose? Most drain the black tank first and then drain the grey tanks to flush out the hose. As Dan said, it takes about a week for two people to fill the black tank. There is a learning curve to all this stuff. I hope you are using disposable gloves when you are using the drain system. Even the grey tanks are full of bacteria.

After we dump, we add 10 gallons of water to black tank along w/ chems and all. Can go (like others have said) 1 week before dumping and like it was said too, toilet started to burp last night/day we were there. Even after dumping, sensor says tank is not empty. When we go for just a w/e, we dump before leaving just to be safe. Are you using a clear plastic elbow to see when tank water is 99% clear?