Black Tank Flusher Not Working?

[drjjj]

Our 3400RL is 11 months old. We have been stationary for most of that time, we are living it in full time while our next stick house is being built (then we hope to travel some). On the recommendation of our selling dealer, we leave both gray tanks open 24/7, and keep the black closed until the toilet "burps", then we dump it. The sensors always show that all three tanks are at least partially full. Our model (2007) has the built in black tank flusher. With our lifestyle we end up dumping the black tank about every 5-6 days. We have noticed that when we first had the trailer you could hear the flusher working while it was on, and see the water and "effluent" coming out after dumping. We always run the flusher at least 20-30 minutes after each dumping. I should also mention that we are using Thetfords "CampaChem" in the tank after each dumping. Later we noticed that while the flusher was running (we also have the clear elbow on the hose) that effluent would "pulse" out intermittently. Now when I turn the flusher on I hear nothing, and don't see any water coming out at all. My thoughts: 1) bring in a hose and fill the tank several times at the toilet and dump; 2) add some kind of organic material (enzymes?) to see if something needs to be "digested". Has anyone else had a similar experience with their flusher? I know some have advocated dumping a 20# bag of ice in the tank and taking the rig for a "ride". I would rather avoid that for at least 2 more months to avoid having to "break camp". Is it possible something has become disconnected? Thanks for any advice.