Vacuum Flush question

The vacuum is held between the duck bill flapper at the outlet of the vacuum pump and the flush seal in the toilet bowl. Usally its a small piece of tissue at the toilet seal that causes the Vacuum to slowly be lost keeping the pump running and the red light on. When the system sits idle for a long time with the switch on, vacuum will slowly be lost causing the pump to cycle back on. This is normal.
When in storage, I turn my pump off,

RED.....
Low vacuum OR high tank level

Does bowl hold water?

If so......then vacuum leak on fittings/hose connections/pump shaft o-rings.
Spray shaving cream on each...flush toilet. If vacuum leak exists it will suck shave cream in.

Otherwise...tank level indicator is sending false signal.

If you are talking about the Macerator toilet and the flush panel showing green and RED. The Black tank has a dedicated sensor just for the Toilet and IF that sensor is showing the tank over 3/4 full it will stop the toilet from flushing(red light). So, if the regular Black tank level monitor shows below 3/4 full and the red light comes on either the Toilet sensor is dirty or the sensor is defective. It is critical to flush a black tank completely when dumping when you have this type toilet. If the tank is at 3/4 or higher then the system is operating correctly. You need to dump the tank. Doug