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Hello
I recently purchased an IceCap ATO with the dual sensors. I watched a few tutorial videos, so I believe it was set up correctly. It is currently in my Nuvo 20 in one of the back compartments. The pump triggers and fills up to the black sensor and stops. Maybe 2 hours later, I hear the alarm is going off. It appears the pump triggered again and kept filling until it was above the white sensor. The alarm signaling it's overfilled and kills the pump? This is the second time it's happened. Any idea what's causing it? I need to be able to rely in it to stop at the black sensor and not keep going until the white sensor triggers the stop.

Please advise.
Thank you.