[DutchmenSport]

To give your sensors a better chance at working, dump your tank, flush it the best you can. Then add about 4-5 gallons of water, dump a half a cup of Dawn Dishwashing Liquid down the toilet, and drive to your next destination. The sloshing of the soap water will clean the crud hanging on the sensors and they will work again. I've been doing this for over 20 years in 4 different travel trailers and fifth wheel. Mine have always worked.

Now, to aid dumping your black tank? If your grey tank and your black tank join to a single outlet (2 valves), get yourself a Flush King valve and attach it to the drain outlet. Now do the following:

1. Drain the black tank completely and leave the valve open.
2. Close the Flush King valve.
3. Open the grey tank valve. This will now allow water from the grey tank to back-flush with force into the empty black tank.
4. Count to 10 and then close the grey tank valve.
5. Now open the Flush King again and let the black tank drain completely again.

Repeat this process 3 times, or until there is not enough water left in the grey tank to make any difference. What little bit of grey water is left after the 3rd back flush, use it to drain and clean out the sewer hose.

If you can get a clear section of drain so you can see what is actually coming out when you back flush, you'll be very surprised what, and how much more comes out.

NOW!! do a final flush with your black tank rinse and just let it run.

A few things are accomplished by doing this, namely you use MUCH less water to clean out your black tank as you are re-using your grey water instead of just dumping it and then using even more clean fresh water to flush the black tank.

Second, if you dump into a Blue Tote to cart away your waste to the dump station, you are not filling the tote multiple times as you are using only water that needs to be dumped anyway.

Third, back flushing cleans your tank, really well.

Now that you have back flushed, add the water, add the Dawn, and drive to your next destination and dump again. Sensors will work, tank is clean, never have smells or odors, and you've helped save the planet. It's a win-win in every direction to back flush.